Transmission Flush

Polluted Human Body
The human body becomes toxic or polluted from both external (exogenous) sources and internal (endogenous) sources. The most common external pathways of toxicity are from inhalation (smoking, air pollution, dental amalgam fillings, sick buildings), ingestion (chemical residues on food, chemicals in water, drugs) injection (vaccinations, flu shots, tattoos), absorption from chemicals from synthetic fabrics, paints, plastics, pesticides and chemical fertilizers sprayed on lawns, and irradiation from medical x-rays, nuclear power plants, bomb testing, uranium mine tailings, cell phones and towers, computer monitors and televisions, microwave ovens, and power grid and radio and satellite transmissions. The modern way of life has not only made our life easier, but has also put our very existence in danger, danger from radiation and pollution.

Damage To Our Immune Systems
The internal sources of toxicity are from fermentation, putrification, and rancidity from undigested foods consumed, and from dehydration, malnutrition, and toxic thoughts and emotions. This endogenous toxicity can also be caused from the effects of exogenous toxins contributing to malnutrition, and inhibition of digestion through damage to the nervous system, immune system, and enzyme systems. With that, we have to take all measures to detoxify.

What is Detoxification?
Detoxification is the process of clearing toxins from the body or neutralizing or transforming them, and clearing excess mucus and congestion. Many of these toxins come from our diet, drug use, and environmental exposure, both acute and chronic. Internally, fats, especially oxidized fats and cholesterol, free radicals, and other irritating molecules act as toxins. Poor digestion, colon sluggishness and dysfunction, reduced liver function, and poor elimination through the kidneys, respiratory tract, and skin all add to increased toxicity. However the most efficient detoxification organ we have is our skin. Our skin contains millions of pores which are equipped to flush out toxins. Flushing out toxins has never been easier with Sauna Therapy!

Symptoms of Being Too Toxic
Constipation and diarrhea, are also indications of foul matter in your intestines. Furthermore, the much more serious problems of cancer and immune system dysfunctions begin with a toxic bowel. Go ahead, purge those foul matter out of your body!

Once we truly understand that the “single greatest challenge our bodies face is the effective removal of wastes and toxins”, we will never again undermine the importance of frequent bowel movements. Do consult with your doctor if you do decide to take any form of laxatives.

Toxic Twentieth Century
Toxicity is of much greater concern in the twentieth century than ever before. There are many new and stronger chemicals, air and water pollution, radiation and nuclear power. We ingest new chemicals, use more drugs of all kinds, eat more sugar and refined foods, and daily abuse ourselves with various stimulants and sedatives. The incidence of many toxicity diseases has increased as well. Cancer and cardiovascular disease are two of the main ones. Our body just can no longer cope with all the toxins around us any longer!

Arthritis, allergies, obesity, and many skin problems are others. In addition, a wide range of symptoms, such as headaches, fatigue, pains, coughs, gastrointestinal problems, and problems from immune weakness, can all be related to toxicity.

Flushing Out Toxins
However, we now have a great way of detoxifying by using our main detox organ, which is our skin. Yes, sweating has proven to release more toxins than frequent bowel movement! Your sweat contains more toxins, urea and heavy metal than urine itself. One great way of sweating out all the toxins is by going through sauna therapy. The heat from the sauna forces your body to pump out all the toxins stored within into your sweat system and thus flushes out all the toxins from your body!

So what are you waiting for? Head to your nearest Sauna! Or better yet, get your very own personal sauna.

The first most importantly thing to do is ask the salesperson for the used car history records. By doing this procedure may save you some time and money. If the used car history report shows that the car in fact was a rental vehicle or has been involved in an accident, there is no point to even looking at it any further recommended. Ask the previous owner or salesperson if any repair has been done to the transmission. If the automatic transmission has already been rebuilt, abstain from buying the car. By saying that… not suggesting that all rebuilt transmissions will have problems but in some cases they work even better than before. The problem is that not all transmission shops can do equally the same high quality job. And since there is no way to verify if it was rebuilt properly or not, it’s better not to take chances. Another thing to be concern about is, ask if the used car you are looking to buy was not used for any towing purposes. Many vehicles that have a towed history like an example towing a trailer. Have much greater risk of having a worn out transmission because of the use for towing that can put a sustainable amount of strain on the transmission over time.

How To Check A Automatic Transmission

You should first get started by checking the transmission fluid level and condition.
With the engine idling, transmission in “Park” (some cars may have different procedures, refer to owner’s manual if needed) remove the automatic transmission dipstick and wipe it off with a clean cloth. Then insert it back in and pull it out again. Check the fluid level, low level may indicate a transmission leak. Pay close attention at the fluid very closely. It helps to drip the fluid on a white paper towel to be able to see fluid condition. The fluid on the paper towel should be clean and transparent, without any metal filings or black flakes. New fluid usually comes out red. Over the time in use it become more of a brownish of color, but it shouldn’t be black.
Try to smell the fluid. It should not have a burnt smell.
It may seem to be difficult to tell at first, but after you check a few similar cars, you’ll be able to pin point the difference with ease.
If you discover that the transmission fluid is too dirty or black, or smells burnt, avoid buying such a car.
Keep in mind, however, that some modern cars simply don’t have the transmission dipstick and require special procedures performed in a shop to check the fluid level. In this case, the only way to check it is by doing a test drive.

Automatic Transmission Indications Of Possible Transmission Problems Overview

One of the indications of a transmission problem is delayed engagement, when there is a long delay between the moment you shift the shifter into “D” (Drive) or “R” (Reverse) and the moment the transmission kicks in.
It’s easier to note delayed engagement after a car was sitting for a while: With the transmission in “P” (Park) start the engine, and wait until the engine rpm has reduced to normal level (650 – 850 rpm).
With your foot holding down the brake pedal, shift to the “D” (Drive) position. Almost immediately the transmission should engage – it feels like the car wants to creep forward. This should happen very smoothly, without a strong jerk or clunk.
Shift to “N” (Neutral), and the transmission should disengage. Now, still holding the brakes, shift to the “R” (Reverse) position. Again, the transmission kicks in almost immediately – you will feel the car wants to creep backward. This also should be very smooth, without a jerk or clunk.
Now, still holding the brake pedal down, try to shift from D to R and back. There should be no strong jerk or clunk.
If there is a notable long delay (more than 1 seconds) between the moment you shift and the moment the transmission kicks in, such a transmission might be either too worn or has some problem.
If you feel a strong jerk or clunk while shifting, the car may have a transmission problem, avoid such a car.

Now it’s time to test drive the car.

With the shifter in “D” (Drive) position drive gently, with smooth and gradual acceleration. Until the vehicle reaches a speed of 30-37 mph (50-60 km/h) or you should feel the gears shifting at least twice (from first to second, and from second to third gear).
All shifts should be done very smoothly, without jerks or slipping.
You should be able to feel when the transmission shifts by the slight change in the engine tone or change in engine rpm. If the transmission is severely worn it may shift with quite a strong jerk, shudder or a delay (especially from first to second gear).
Driving at a speed of 25-30 mph (40-50 km/h) if you press down the accelerator pedal for a few seconds, you should feel downshifting to the lower gear, if the automatic transmission works properly.

The next step: check overdrive.

While driving at 60-70 km/h or 35-45 mph on a level road, without using the accelerator, switch overdrive ON. You should feel an up shifting to the next speed. Switch it to “OFF,” and you should feel a downshifting.
Another thing to watch out for that may indicate the transmission has a problem is the slipping. When the transmission is excessively worn it may slip – which means you press the accelerator, the engine rpm increases but the speed remains the same.

While during a test drive you feel any problems such as the transmission seems to be slipping or shifts with a jerk or shudder or if the transmission got stuck in some gear, or has trouble shifting into a particular gear (for example, from second to third), You should avoid buying such a car.
Always try to test drive the car as long as possible. Often the transmission may work well when it’s cold but when it’s warmed up it starts giving troubles or vice versa. So, it is better to spend more time checking the transmission thoroughly than later repairing it at your expense. Normally there should be no shudder, no noises or any kind of strong jerks at any speed and at any engine temperatures while any shifting is going on. If the salesperson tells you that the jerks or shudder or any other abnormal transmission behavior is “normal” for this car or it’s just because the car is cold or anything alike…, don’t trust them. If the “check engine” and, or a flashing overdrive light comes on while driving, have the vehicle inspected with a certified mechanic before buying a vehicle.

How To Check A Manual Transmission

You should first check for oil leaks. There should absolutely not be any leaks.

Now, shift the transmission lever into neutral. Apply the parking brake. With the engine idling, press the clutch pedal all the way, hold it down, and listen for noises. Then release the pedal and listen for noises again. There should be no loud noises at either positions.
The next step will be to take the car for a test drive.
Try to drive the vehicle at different speeds in all gears, one by one. Every gear should shift smoothly and easily without any noises or jerks. While driving at the second or third gear, try to press down sharply on the accelerator pedal for an instance. The clutch should not slip.
If you feel any slipping (example like… the engine rpm increases but the speed remains the same), then the clutch most likely has to be replaced.
Try to drive with acceleration and deceleration there should be no grinding, whining or humming noise under any condition circumstances. All the gears should shift easily and noiselessly free.

Now that you know a whole lot more about…, How To Check A Used Car For Transmission Problems Before You Buy It. You may consider shopping at CarShopster.com for Used cars, New cars for Sale Online. We have over 5 million Used Cars, New Cars, listings at Local or Nationwide dealerships and automotive resources of cars for sale inventory in your area.

Owning a car entails for great responsibility as well as setting aside funds for additional expenses that goes on maintenance and repairs. The car contains at least six types of fluids which need to be periodically replenished or replaced namely engine oil, transmission fluid, anti-freeze/coolant, windshield washer solvent and fuel. The number six on the list is brake fluid which is often the neglected one. You’ve known about topping off brake fluid but changing it may be new to most car owners.

According to Car Care Council, the brake fluid of a typical vehicle is prone to contamination in two years time or less. This is because the fluid absorbs moisture which finds its way through the hydraulic system. During heavy braking conditions such as those encountered when driving in mountainous or hilly roads or when towing a trailer, the moisture in the overheated fluid vaporizes resulting to reduction on the braking efficiency.

Such condition can also happen even under normal driving circumstances especially if the brake fluid is seriously contaminated. There are actually two things that can happen. The first one is for the contaminated fluid to vaporize and second it has the ability to also freeze up either way the result is the same which is reduced braking efficiency.

Brake fluid must maintain a stable viscosity throughout its operating temperature range. If it’s too thick or too thin; it would impaired the braking action of the vehicle. Beyond the vaporization hazard moisture creates an additional problem for owners of vehicles especially those equipped with anti-lock braking systems (ABS) since ABS components often get rusted. A rusted and corroded ABS components is never good news since it’s very expensive to replace.

So how would a car owner know when its time to change their car’s brake fluid? Car Care Council recommends changing brake fluid every two years or for every 24,000 miles traveled. Plus, the Council also suggests a change in brake pads or shoe replacement. The brake system to choose would depend on your car make say if you own a Volkswagen then it is only sensible that you purchase Volkswagen brakes system. And in between as preventive measure, a professional brake technician should check the condition of the fluid with an accurate fluid test safety meter that is inserted into the master cylinder reservoir to record the fluid’s boiling point.

Volkswagen, the Company

Volkswagen is considered to be an icon of the 20th century due to the countless legendary cars it has produced. Volkswagen is a German word for people’s car. It started as a concept formed by Ferdinand Porsche in 1934. He wants to produce quality but affordable transport for the German people. He produced a working prototype in just a year.

Ferdinand Porsche has created a masterpiece in the form of a beetle-shaped sedan that was later on called the Volkswagen. The Beetle because of its unique design and aesthetic appeal has become very popular as a fact it has become the best selling car of all time.

Volkswagen was born in an era that is said to be designed for the privilege few and the vehicle has provided the German people would something to look forward to.

By the year 1942, 70,000 Volkswagens were produced. Three years after in a swift recovery after the war, Volkswagen was able to produce 2,000 vehicles but this time it was not for public sale but especially manufactured for the Allied Forces and the new German Post Office. The next production of Volkswagen was after three years again, 1948, wherein it produced a total of 25,000 vehicles from its production lines in Wolfsburg. It was also during that time when Beetles for export to the US was built. The following year 1949 and additional 25,000 Volkswagens were built including the Karmann convertible which became the best selling convertible in the world.

The year 1955 signaled the growth of Volkswagen into a world corporation when it produced a million Volkswagens. It was also on that year when the automaker started building factories and working communities in United States, Brazil, and Canada. The German automaker has not forgotten to also help its fellow countrymen; it has built working communities in major centers in Western Europe.

Less than two decades later The Beetle which was a people’s car was able to overtake Ford’s famous Model T. For the last fifteen years of the millennium Volkswagen has emerged as a true global force in the auto industry. Its acquisition and redevelopment of popular brands like the Audi, SEAT, Skoda, and Lamborghini has strengthen further its standing as one of the largest automaker in the world.

There was a time that when you filled your gasoline tank, a friendly, knowledgeable and efficient attendant cheerfully checked your oil, coolant, and transmission fluid. He cleaned your windshield, checked your wiper blades and sometimes even your tires. But with the advent of the self-service gas station, this person has slowly become extinct. At most stations, the only available human is the cashier whose knowledge is limited to the price of the gasoline.

Although checking fluid levels is not something you want to take your car to the repair shop to have done, it is a very important task and if neglected, can result in major maintenance problems. So it has now become something you need to do yourself. Fortunately it isn’t difficult.

To check the engine oil, first park your car on a level surface and be sure the parking brake is engaged. Wait for a while, and then raise the hood. Look for the dipstick. It normally reads, “engine oil.” Your owner’s manual should have a picture, if you have difficulty.

Pull the dipstick and wipe it with a clean rag or paper towel. Then replace it; ensuring it goes all the way back down. Now pull the dipstick again. At the very bottom you see a series of marks and the word “full.” Your oil should be on the full mark.

Look at the color. It should be transparent. If it is black, you need an oil change immediately. When it is dark brown, you don’t need to change it right away but you will need to do so very soon. If it has the appearance of coffee laced with milk, you have a problem. Your coolant is mixing with your engine oil due to a mechanical mal-function. You need to take the car to a repair shop.

If your oil is low, you need to add more oil. Do this a little at a time, waiting for the oil to go down, and checking the dipstick after each addition. Be very careful not to overfill it as this can damage your engine.

On most cars you check your transmission fluid with the shift in park and the engine idling. However, you should first check your owner’s manual to be sure this procedure is proper for your car. The owner’s manual will also show you where the transmission dipstick is located.

Pull the dipstick and wipe it with a clean rag free of lint. Then replace it ensuring that it settles all the way down into place. Pull it again and check. If your car has just been driven and is warm, the fluid will register at the upper end of the “hot” mark. If the engine is cold, then the fluid level should be within the cold marks.

If you have to add fluid, be sure you use the fluid recommended in the owner’s manual. If you don’t do this, you can damage your transmission. If adding fluid, add only a small amount, wait a few minutes and check the dipstick. Do not overfill.

To check coolant, look at your coolant overflow tank. If the level is between the “low” and “full” marks, it is okay. If it is low, pour some coolant into the overflow tank until you reach the “full” mark. Be careful not to open the coolant overflow tank or the radiator when the engine is warm. Wait for it to cool off completely.

Maintaining proper levels of all fluids is essential to prevent costly mechanical problems.

Shopping for a hybrid car is quite different from shopping for a regular car. You know that the hybrid will be easy on your budget and great for the environment but what else do you need to ask yourself? Here is a list of questions you need to answer to be able to find your ideal hybrid car.

Do you drive mostly on the highway or do you stick to city roads more? Many hybrids are great for highway driving but others are better when it comes to city roads. Figuring out what kind of driver you are is key to picking the right hybrid to meet your needs.

Do you need to save a lot of gas? The Honda Civic and the Toyota Prius hybrids are both excellent hybrids when it comes to saving a lot of gas. There are also many others who will run a close second to these cars.

Ar you interested in a sedan or would you rather have an SUV? As of today the hybrid car buyer is limited to one or the other but come the year 2009 you will also be able to choose from a full-sized pickup truck. Both the Chevy Silverado and the GM Sierra will be available in a hybrid.

Do you require a lot of space? Once you start shopping for a hybrid you will notice that many of the cars that were once roomier in a regular car are not as large on the interior now that they are a hybrid. If you require a lot of room you might want to make sure you throughly check to see if the hybrid you want has enough leg and head room to accommodate you comfortably. Don’t forget to think about traveling. Many new hybrids are short on storage space.

Are you interested in a hybrid that is less or more dependent on it’s battery pack? With hybrid cars some use the battery pack more than others will. They have the ability to switch from the gas engine while coasting or at very low speeds. If your interested in a hybrid like this then the Toyota Camry, Toyota Prius or even the Honda Civic is the one to check out.

Do you have the ability to pay for a hybrid? Hybrid cars cost more than regular cars by about $3,000 to $6,000. This increase can greatly effect what cars you are able to afford and whether you can have any extras.

Did you know you can receive a tax credit from purchasing a hybrid? The New Energy tax credit is give when less than 60,000 units of any hybrid have been sold. This credit is up to $3,400. Once 60,00 units have sold the government will begin reducing the credit. Ask your dealer for more information.

People buy hybrid cars for many reasons. Once you have decided why your purchasing a hybrid it will make the choice in which hybrid to purchase that much easier.

Section 1: Introduction

Although the Internet Protocol IPv4 was giving efficient service over than 20 years ,

but the new Internet Protocol IPv6 provides higher efficiency like having enough

level of IPs, stronger security and mobility. In fact it is good to evaluate the performance benefits that we can get from IPv6 protocol in compare to the IPv4 protocol. We can upgrade the existing IPv4 infrastructure to the next generation Internet Protocol(IPv6) and get its advantages using the transition mechanisms.

When IPv4 was designed most of networks had just few nodes, low bandwidth, high latency, and high error rates. Most common applications at that time were FTP,e-mail, and so on.In the early 1990’s, the computer industry expanded with coming the personal computers (PCs) to the market. The internet also developed and electronic businesses or e-commerce started. The market demand was the biggest factor in the Internet’s revolution. As the fast grow of the Internet was detected in the early 1990’s, it was

showing that the IPv4 address space would be finish by the end of the century. In this

regard, some mechanisms such as Network Address Translator (NAT) have extended the life of IPv4, but it was not a logical solution.Today, the market looks completely different than it was in the 1980’s. Although FTP, and e- mail are still very popular today but new applications such as video conferencing, Voice-over-IP, E-Commerce, Mobiles, and etc , have led the Internet

Engineering Task Force (IETF) to seek a new Internet Protocol, that we call it IPv6.

IPv4 and IPv6 are incompatible protocols. For this reason, transition to the new protocol cannot be expected to be painless, and will involve significant costs for service providers and customers alike. If we compare the costs of transition with the non-transition mode or using IPv4 with supporting new services, then it can help us identify the best time to start the transition process .Whenever transition begins there will be no single “flag day” on which the all-IPv4 network turns into an IPv6 network. At the Internet level, transition will be a lengthy

process, with the two protocols existing side by side for many years to come. To facilitate transition, the IETF (Internet Engineering Task Force) has set up a work group called ngtrans (Next Generation TRANSition) which specifies mechanisms for supporting interoperability between IPv4 and IPv6. In particular, the group has focused on two major problems:

•How to make IPv6 terminals communicate with IPv4 terminals.

•How to transport IPv6 over an IPv4 network so that IPv6 “islands” interconnected via the IPv4-based Internet can communicate.

This second problem, which is extremely important in the initial stage of IPv6

deployment, will be joined in the future by the reciprocal problem: how to transport

IPv4 over IPv6. However; discussion of this issue have been postponed until the presence of IPv6 reaches to a significant point on the Internet.

Work on these problems has led to the development of a set of transition mechanisms, each targeted to a particular range of uses and applications.

Section 2: IP Overview

Internet protocol is the set of techniques used by many hosts for transmitting data over

the Internet. The current version of the Internet protocol is IPv4, which provides a 32-bit address system.

Internet protocol is a “best effort” system, meaning that no packet of information sent

over it is assured to reach its destination in the same condition it was sent. Often other

protocols are used in tandem with the Internet protocol for data that for one reason or

another must have extremely high fidelity.

Every device connected to a network, be it a local area network (LAN) or the Internet,

is given an Internet protocol number. This address is used to identify the device uniquely among all other devices connected to the extended network.

2.1 : Features of IP

IP is a connectionless protocol. This means that it has no concept of a job or a session.

Each packet is treated as an entity in itself. IP is rather like a postal worker sorting

letters. He is not concerned with whether a packet is one of a batch. He simply routes

packets, one at a time, to the next location on the delivery route.

IP is also unconcerned with whether a packet reaches its eventual destination, or

whether packets arrive in the original order. There is no information in a packet to

identify it as part of a sequence or as belonging to a particular job. Consequently, IP

cannot tell if packets were lost or whether they were received out of order. IP is an

unreliable protocol. Any mechanisms for ensuring that data sent arrives correct and intact are provided by the higher- level protocols in the suite.

2.2 : IP Routing

So how does an IP packet addressed to a computer on the other side of the world find

its way to its destination? The basic mechanism is very simple.

On a LAN, every host sees every packet that is sent by every other host on that LAN.

Normally, it will only do something with that packet if it is addressed to itself, or if

the destination is a broadcast address.

A router is different. A router examines every packet, and compares the destination

address with a table of addresses that it holds in memory. If it finds an exact match, it

forwards the packet to an address associated with that entry in the table. This

associated address may be the address of another network in a point- to- point link, or

it may be the address of the next-hop router.

If the router doesn’t find a match, it runs through the table again, this time looking for

a match on just the network ID part of the address. Again, if a match is found, the

packet is sent on to the address associated with that entry.

If a match still isn’t found, the router looks to see if a default next- hop address is

present. If so, the packet is sent there. If no default address is present, the router sends

an ICMP “host unreachable” or “network unreachable” message back to the sender. If

you see this message, it usually indicates a router failure at some point in the

network.

The difficult part of a router’s job is not how it routes packets, but how it builds up its

table. In the simplest case, the router table is static: it is read in from a file at start- up.

This is adequate for simple networks. You don’t even need a dedicated piece of kit for

this, because routing functionality is built into IP.

Dynamic routing is more complicated. A router builds up its table by broadcasting

ICMP router solicitation messages, to which other routers respond. Routing protocols

are used to discover the shortest path to a location. Routes are updated periodically in

response to traffic conditions and availability of a route. However, the details of how

this all works is beyond the scope of this report.

2.3 : Future of the Internet

As we can see the Internet will have a serious problem in a few years. Due to its

amazing growth and the limitations in its design and facilities , there will be a

problem when no more free addresses are available for connecting to new hosts or

assigning to a new device. At that point, no more new web servers can be set up, no

more users can sign up for accounts at ISPs, and no more new machines can be set up to access the web or join in online games.

Several solutions have been made to solve the problem. A very popular approach is to

not assign a worldwide unique address to every user’s machine, but rather to assign

them “private” addresses, and hide several machines behind one official, globally

unique address. This technique is called “Network Address Translation” or NAT. It

has problems, as the machines hidden behind the global address can’t be addressed,

and as a result of this, opening connections to them which are used in online gaming,

peer-to-peer networking, and etc, is not possible.

A different approach to the problem of Internet addresses getting scarce is to discard

the old Internet protocol with its limited addressing capabilities, and use a new

protocol that does not have these limitations. The protocol or actually, a set of

protocols used by machines connected to form today’s Internet is known as the

TCP/IP (Transmission Control Protocol, Internet Protocol), and version 4 currently in

use has all the problems described above.

Switching to a different protocol version that does not have these problems of course

requires for a new version to be available. And actually, there is a better version.

Version 6 of the Internet Protocol (IPv6) provides future inquiries on address space,

and also addresses other features such as privacy, encryption, and better support of

mobile computing as well.

Assuming a basic understanding of how today’s IPv4 works, this report is intended

as an introduction to the IPv6 protocol. The changes in address formats and name

resolution are covered. After that, it is shown how to use IPv6 by using a simple-yet-

efficient transition mechanism called 6to4.

Section 3 : IPv6 vs IPV4

When telling people to migrate from IPv4 to IPv6, the question you usually hear is “Why?”.

There are actually a few good reasons to move to the new version:

• Bigger address space

• Support for mobile devices

• Built-in security

3.1 : Bigger address space

The bigger address space IPv6 offers is the most obvious enhancement it has over

IPv4. While today’s Internet architecture is based on 32-bit wide addresses, the new

version has 128-bit technology available for addressing. Base on the enlarged address

space, workarounds like NAT don’t have to be used anymore. This allows full, unconstrained IP connectivity for today’s IP-based machines as well as upcoming mobile devices like PDAs and cell phones all will benefit from full IP access through GPRS and UMTS.

3.2 : Mobility

When mentioning mobile devices and IP, it’s important to note that a special protocol

is needed to support mobility, and implementing this protocol that is called “Mobile

IP” is one of the requirements for every IPv6 stack. Thus, if we have IPv6 going, we

have support for roaming between different networks, with global notification when

we leave one network and enter the other one. Support for roaming is possible with

IPv4 too, but there are a number of hoops that need to be jumped in order to get things

working. With IPv6, there’s no need for this, as support for mobility was one of the

design requirements for IPv6.

3.3 : Security

Besides support for mobility, security was another requirement for the successor to

today’s Internet Protocol version. As a result, IPv6 protocol stacks are required to

include IPsec. IPsec allows authentication, encryption, and compression of IP traffic.

Except for application-level protocols like SSL or SSH, all IP traffic between two

nodes can be handled without adjusting any applications. The benefit of this is that all

applications on a machine can benefit from encryption and authentication, and that

policies can be set on a per-host (or even per-network) basis, not per application/service.

Section 4 : IPV6 Addressing

The IPV6 Addressing properties is presented in this section.

4.1: Multiple addresses

In IPv4, a host usually has one IP number per network interface or even per machine

if the IP stack supports it. Only very rare applications like web servers result in

machines having more than one IP number.

In IPv6, this is different. For each interface, there is not only a globally unique IP

address, but there are two other addresses that are of interest: The link-local address,

and the site-local address. The link-local address has a prefix of fe80::/64, and the

host bits are built from the interface’s EUI64 address. The link-local address is used

for contacting hosts and routers on the same network only, the addresses are not

visible or reachable from different subnets. If desired, there’s the choice of either

using global addresses as assigned by a provider, or using site-local addresses.[16]

Site-local addresses are assigned the network address fec0::/10, and subnets and hosts

can be addressed just as for provider-assigned networks. The only difference is that

the addresses will not be visible to outside machines, as these are on a different

network, and their site-local addresses are in a different physical net. As with the 10/8

network in IPv4, site-local addresses can be used, but don’t have to be. For IPv6, it’s

most common to have hosts assigned a local link and a global IP address. Site-local

addresses are rather uncommon today, and is no substitute for globally unique

adresses if global connectivity is required.

4.2 : Multicasting

In IP land, there are three ways to talk to a host: unicast, broadcast, and multicast. The

most common way to talk to a host is by talking to it directly using its unicast address.

In IPv4, the unicast address is the “normal” IP address assigned to a single host, with

all address bits assigned. The broadcast address used to address all hosts in the same

IP subnet has the network bits set to the network address, and all host bits set to “1″

which can be easily done using the netmask and some bit operations. Multicast addresses are used to reach a number of hosts in the same multicast group, which can be machines spread across the Internet. Machines must join multicast groups

explicitly to participate, and there are special IPv4 numbers used for multicast addresses, allocated from the 224/8 subnet. Multicast isn’t used very much in IPv4, and only few applications use it.In IPv6, unicast addresses are used the same as in IPv4, no surprise there all the

network and host bits are assigned to identify the target network and machine.

Broadcasts are no longer available in IPv6 in the way they were in IPv4, this is where multicasting comes into play. Addresses in the ff::/8 network are reserved for multicast applications, and there are two special multicast addresses that supersede the broadcast addresses from IPv4. One is the “all routers” multicast address, the others is for “all hosts”.

The details about IPv6 are in general the way they were proposed in the RFCs by IETF, however we chose to use Microsoft Windows 2003 as the platform to implement the tests. Due to their early stages of development, the IPv6 protocol stack in Windows 2003 still has many problems, such as fragmentation issues, no support

for IPSec, a native security feature, etc…

Microsoft has two different implementations of an IPv6 stack both for Windows NT 5.0 and Windows 2003. The older stack, known as the “Microsoft Research IPv6 Release 1.4”, works under both NT 4.0 and Win2K; the newer stack, known as the

“Microsoft IPv6 Technology Preview for Windows 2003” works under Windows 2003. Both stacks require an existing IPv4 stack to be previously installed.

Once installed, besides giving the Windows environment the support for IPv6, it

creates a whole new set of routines, such as “ping6”, “tracert6”, which are similar in

function to “ping” and “tracert”, but work with the new IPv6 stack. The good part about the IPv6 implementation that Microsoft created is that they embedded the IPv6 socket creation in the Winsock2 API. That means that they added a few more functions when you create the sockets, however, the fundamentals remained the same,

and thus a programmer that can make an IPv4 application can most likely learn how

to make a simple IPv6 application as well.

Internet Protocol version 6 is designed as an evolutionary upgrade to the Internet

Protocol (IPv4) and will, in fact, coexist with the older IPv4 for some time. IPv6 is designed to allow the Internet to grow steadily, both in terms of the number of hosts connected and the total amount of data traffic transmitted; it will have a 128 bit address looking like FFFF:FFFF:FFFF:FFFF, and it will support up to

340,282,366,920938,463,463,374,607,431,768,211,456unique addresses.in Table1 we can see the advantages of IPV6 versus IPV4 .

The IPv6 header is always present and is a fixed size of 40 bytes. The fields in the

IPv6 header are described briefly below.

The fields in the IPv6 header are:

Version – 4 bits are used to indicate the version of IP and is set to 6.

Traffic Class – Indicates the class or priority of the IPv6 packet. The size of this field

is 8 bits.The Traffic Class field provides similar functionality to the IPv4 Type of

Service field.

Flow Label – Indicates that this packet belongs to a specific sequence of packets

between a source and destination, requiring special handling by intermediate IPv6

routers. The size of this field is 20 bits. The Flow Label is used for non-default quality

of service connections, such as those needed by real- time data (voice and video). For

default router handling, the Flow Label is set to 0. There can be multiple flows between a source and destination, as distinguished by separate non-zero Flow Labels.Payload Length – Indicates the length of the IP payload. The size of this field is 16 bits. The Payload Length field includes the extension headers and the upper layer PDU. With 16 bits, an IPv6 payload of up to 65,535 bytes can be indicated. For payload lengths greater than 65,535 bytes, the Payload Length field is set to 0 and the Jumbo Payload option is used in the Hop-by-Hop Options extension header.

Next Header – Indicates either the first extension header (if present) or the protocol

in the upper layer PDU (such as TCP, UDP, or ICMPv6). The size of this field is 8

bits. When indicating an upper layer protocol above the Internet layer, the same

values used in the IPv4 Protocol field are used here.

Extension Header – Zero or more extension headers can be present and are of

varying lengths. A Next Header field in the IPv6 header indicates the next extension

header.Within each extension header is another Next Header field that indicates the

next extension header. The last extension header indicates the upper layer protocol

(such as TCP, UDP, or ICMPv6) contained within the upper layer protocol data unit.

The IPv6 header and extension headers replace the existing IPv4 IP header with options. The new extension header format allows IPv6 to be augmented to support future needs and capabilities. Unlike options in the IPv4 header, IPv6 extension headers have no maximum size and can expand to accommodate all the extension data

needed for IPv6 communication.

Hop Limit – Indicates the maximum number of links over which the IPv6 packet can

travel before being discarded. The size of this field is 8 bits. The Hop Limit is similar

to the IPv4 TTL field except that there is no historical relation to the amount of time

(in seconds) that the packet is queued at the router. When the Hop Limit equals 0, the

packet is discarded and an ICMP Time Expired message is sent to the source address.

Source Address –Stores the IPv6 address of the originating host. The size is 128 bits.

Destination Address – Stores the IPv6 address of the current destination host. The

size of this field is 128 bits. In most cases the Destination Address is set to the final

destination address.

However, if a Routing extension header is present, the Destination Address might be

set to the next router interface in the source route list.

Section 5 : Transition Mechanisms

As IPv6 is finally beginning to mature, it is evident that methods of upgrading the

Internet need to be found. One idea would be to turn off the entire Internet at 12 pm,

upgrade the network infrastructure include routers, protocol stacks, …and turn the

Internet back on at 6 am and hope everything works fine and correct.

This is unrealistic due to the fact that it would cost more money than it is imaginable,

the time would be way too short, and nothing ever works as good as it is in theory.

More gradual transition methods have evolved, ones which are likely to happen over

the course of 10 years or so. Some of the transition mechanisms are:

Dual Stack

SIIT – Stateless IP/ ICMP Translator

AIIH – Assignment of IPv4 Global Addresses to IPv6 Hosts

NAT – Protocol Translator – has scaling and DNS issues, and has single point of failure disadvantage

Tunnel Broker – dynamically gain access to tunnel servers, but has authentication and scaling issues;

6-to-4 Mechanism – dynamic stateless tunnels over IPv4 infrastructure to connect 6-to-4 domains

IPv6 in IPv4 tunneling – Allows existing infrastructure to be utilized via manually configured tunnels

o Host-Host Tunneling

o Router-Router Tunneling

o Host-Router and vice versa Tunneling

5.1 : Dual Stack:

The basic approach for permitting all communications is the so-called dual stack IP,

where each new host, server, router or other item of equipment dealing with the IP level can support both protocols. In this way, communication between IPv6 terminals

takes place directly, while an IPv4/IPv6 terminal which must communicate with an IPv4-only terminal can do so in IPv4. This approach is not particularly burdensome for hosts and servers, as it is a software upgrade which has no significant impact on the system. Nevertheless, the main drawback of this approach is the need to maintain

a multi-protocol network with a double routing infrastructure, which increases administrators’ work load. In addition, generalized use of the dual stack IP model will not be possible when address space exhaustion reaches the point that new IPv4 addresses can no longer be assigned.

To overcome these problems, several solutions for interoperation between IPv6-only networks and IPv4-only networks have been specified which permit end-to-end communication between heterogeneous terminals:

•Dual stack IP ALG devices which make it possible to perform protocol translation at the borders between non-homogeneous networks through the use of application proxies implemented on dual stack servers.

•NAT-PT (Network Address Translator – Protocol Translator) devices, which make it possible to perform address and protocol translation at the borders between non-homogeneous networks at IP level.

•The Dual Stack Transition Mechanism, or DSTM, which proposes to use the dual stack IP approach on the basis of IPv4 addresses assigned dynamically only when needed, and the use of IPv4 over IPv6 tunneling in order to cross the local IPv6 network before accessing the outer IPv4 network.

Though these transition mechanisms have the same shortcomings as the similar mechanisms proposed for interconnecting separate IPv4 networks, they provide a significant advantage for the future. Thus, while the mechanisms for IPv4 are final,and can no longer be done without, those for the transition towards IPv6 are instrumental in ensuring coexistence between IPv4 and IPv6, which should come to an end once the Internet operates entirely under IPv6.

IPv6 was delivered with migration techniques to cover every conceivable IPv4 upgrade case, but many were ultimately rejected by the technology community, and today we are left with a small set of practical approaches.

Dual stack is involve with running IPv4 and IPv6 at the same time. End nodes and routers/switches run both protocols, and if IPv6 communication is possible that is the preferred protocol.

A common dual-stack migration strategy is to make the transition from the core to the

edge. This involves enabling two TCP/IP protocol stacks on the WAN core routers,then perimeter routers and firewalls, then the server-farm routers and finally the desktop access routers. After the network supports IPv6 and IPv4 protocols, the process will enable dual protocol stacks on the servers and then the edge computer

systems.

Another approach is to use tunnels to carry one protocol inside another. These tunnels

take IPv6 packets and encapsulate them in IPv4 packets to be sent across portions of the network that haven’t yet been upgraded to IPv6.

Other techniques, such as network address translation–protocol translation (NAT-PT)

simply translate IPv6 packets into IPv4 packets. These translation techniques are more

complicated than IPv4 NAT because the protocols have different header formats.Translation techniques were intended to be used as a last resort. Using dual-stack and tunneling techniques is preferable to using NAT-PT.

It will be easier to try to run everything in a dual-stack mode first and then remove the

IPv4 protocol over time. Currently there aren’t many systems being developed for IPv6-only communications, but there are many systems that work in dual-stack mode. Microsoft’s new operating systems, for example, have a dual-layer architecture that makes for seamless operation of either protocol. Therefore, migration plans should maximize the use of dual stack and minimize the amount of tunneling. It should also

be mentioned that running dual stack is not the final state. We can’t forget that full

migration to IPv6 is the final destination.

Dual stack IPV4/IPV6

In the 1990s the network industry used the phrase “Switch where you can, route where you must.” However, over time the performance gap between routing and switching closed. For IPv6 transitions the new moniker will be “Dual stack where you can, tunnel where you must.”

5.2 : IPv6 in IPv4 tunneling:

IPv6 in IPv4 tunneling is one of the easiest transition mechanism by which two IPv6

hosts / networks can be connected with each other while running on existing IPv4 networks through establishing some special routes called tunnels. In this technique, IPv6 packets are encapsulated in IPv4 packets and then are sent over IPv4 networks like ordinary IPv4 packets through tunnels. At the end of tunnel these packets are

decapsulated to the original IPv6 packets.

The following are some important characteristics of tunneling mechanism:

When encapsulating a datagram, the TTL in the inner IP header is decremented by

only one if the tunnel is being done as part of forwarding the datagram; otherwise the

inner header TTL is not changed during encapsulation. If the resulting TTL in the

inner IP header is zero, the datagram is discarded and an ICMP Time Exceeded message is returned to the sender.

Therefore, an encapsulator will not encapsulate a datagram with TTL=0.

Encapsulation of IPv6 in IPv4:

o Utilizes IPv4 routing and properties.

o Loses special IPv6 features.

o Requires a hole in firewall to allow through protocol 41 (IP in IP).

There are two types of tunnels: manual and dynamic. Manually configured IPv6 tunneling requires configuration at both ends of the tunnel, whereas dynamic tunnels are created automatically based on the packet destination address and routing. Dynamic tunneling techniques simplify maintenance compared with statically

configured tunnels, but static tunnels make traffic information available for each

endpoint, providing extra security against injected traffic.

There are, in fact, concerns over the security of tunneling techniques. For example, with dynamic tunnels it isn’t easy to track who is communicating over the transient tunnels, and you don’t know the tunnel destination endpoint. It is a scary proposition when your routers communicate with other nonauthenticated routers. It is also

possible to send forged traffic toward a tunnel endpoint and get traffic spuriously inserted into the tunnel. Tunneling creates situations in which traffic will be encapsulated, and many firewalls won’t inspect the traffic if it is in a tunnel. Allowing IP Protocol 41 (IPv6 encapsulated in IPv4) through an IPv4 firewall is not a best

practice. This is like creating an “IPv6 permit any any all” rule through the firewall.

Tunnels will constantly have to be changed and monitored as your transition progresses. Tunnels will also have to be removed when the IPv6 ocean gets larger and we migrate to full IPv6. Tunnels are, therefore, just a transitional technique, and troubleshooting in an environment full of tunnels will be challenging.

Dynamic tunnel techniques don’t create tunnel interfaces that can be monitored with SNMP. Dynamic tunnel techniques such as 6 to 4 use 2002::/16 addresses, which means you will need to re-address the network twice as part of the transition to IPv6.

Many of the dynamic tunneling techniques are also unable to forward multicast traffic and can’t traverse an IPv4 NAT in the middle of the network.

If a tunnel falls entirely within a routing domain, it will be considered as plain serial

link by interior routing protocol such as RIP or OSPF. But if it lies between two routing domains it needs exterior protocols like BGP etc..

In case of congestion in the tunnel, an ICMP Source Quench message will be issued in order to inform the previous node of the congestion.

In different types of tunneling, only de/encapsulation points are varied depending on

the start and end of tunnels, however the basic idea remains the same.

IPv6 tunneling enables the iSeries server to connect to IPv6 nodes (hosts and routers) across IPv4 domains. Tunneling permits isolated IPv6 nodes or networks to communicate without changing the underlying IPv4 infrastructure. Tunneling allows IPv4 and IPv6 protocols to cooperate, and thereby provides a transitional method of

implementing IPv6 while retaining IPv4 connectivity.

A tunnel consists of two dual-stack (IPv4 and IPv6) nodes on an IPv4 network. These dual-stack nodes are capable of processing both IPv4 and IPv6 communications. One of the dual-stack nodes on the edge of the IPv6 infrastructure inserts an IPv4 header in front of (encapsulates) each IPv6 packet that arrives and sends it as though it were normal IPv4 traffic, through existing links. IPv4 routers continue to forward this traffic. On the other side of the tunnel, another dual-stack node removes the extra IP header from the IPv6 packet (decapsulates) and routes it to the ultimate destination using standard IPv6.

IPv6 tunneling runs over configured tunnel lines, which are virtual lines. Configured tunnel lines provide IPv6 communications to any node with a routable IPv4 address that supports IPv6 tunnels. These nodes may exist anywhere, that is, within the local IPv4 domain or within a remote domain.

Configured tunnel connections are point-to-point.To configure this type of tunnel

line, you must specify the local tunnel endpoint (IPv4 address), such as 124.10.10.150, and the local IPv6 address, such as 1080:0:0:0:8:800:200c:417a. We must also create an IPv6 route to enable traffic to travel through the tunnel. As we create the route, we will define one of the tunnel’s remote endpoints (IPv4

address) as the route’s next hop. We may configure an unlimited number of endpoints

for an unlimited number of tunnels.

5.2.1 : Host-to-Host Tunneling

In host to host tunneling method, encapsulation is done at source host and ecapsulation is done at destination host. So the tunnel is created in between two hosts supporting both IPv4 and IPv6 stacks. So in this way encapsulated datagrams are sent through the tunnel over the IPv4 network.

Both hosts having dual stack encapsulate the packets of IPv6 in IPv4 packets and transmit over the network as an IPv4 packet utilizing all the characteristics and routing mechanisms of IPv4. With this transition mechanism, it is possible to support IPv6 simply by upgrading the end hosts protocol stacks to IPv6 while leaving the IPv4

infrastructure unchanged.

5.2.2 : Router-to-Router Tunneling

In router to router tunneling mechanism, encapsulation is done at edge router of

originating host and decapsulation is done in the same way at edge router of destined host. The tunnel is created in between two edge routers supporting both IPv4 and IPv6 stacks. Therefore, the end hosts can support native IPv6 protocol stack while the edge routers create the tunnels and handle the encapsulation and decapsulation in order to transmit the packets over the existing IPv4 infrastructure.

The IPv6 datagrams are forwarded from host to edge routers while encapsulation takes place at the router level; similarly at the other end, the reverse process takes place. In this method, both edge routers need to support dual stacks and established a tunnel prior to transmission.

5.2.3 : Host-to-Router Tunneling

In host to router tunneling mechanism, encapsulation is done at originating host and

decapsulation is done in the same way at edge router of destined host and vice versa.

The tunnel is created in between one host and one edge router both of them supporting both IPv4 and IPv6 stacks. So in this way encapsulated datagrams are sent through the tunnel over the existing IPv4 network. The same process can happen the other way around, from one edge router to an end host.

The tunnel is therefore established between the host and the router. In this method one

dual stack supporting router and one dual stack supporting host is required.

5.3 : Overlay Tunnels for IPv6

Overlay tunneling encapsulates IPv6 packets in IPv4 packets for delivery across an

IPv4 infrastructure (a core network or the Internet).By using overlay tunnels, we can

communicate with isolated IPv6 networks without upgrading the IPv4 infrastructure

between them. Overlay tunnels can be configured between border routers or between

a border router and a host; however, both tunnel endpoints must support both the IPv4

and IPv6 protocol stacks as we can see in figure

4 . Cisco IOS IPv6 supports the

following types of overlay tunneling mechanisms:

• Manual

• Generic routing encapsulation (GRE)

• IPv4-compatible

• 6to4

• Intra-Site Automatic Tunnel Addressing Protocol (ISATAP)

Note Overlay tunnels reduce the maximum transmission unit (MTU) of an interface

by 20 octets (assuming the basic IPv4 packet header does not contain optional fields).

A network using overlay tunnels is difficult to troubleshooting. Therefore, overlay tunnels connecting isolated IPv6 networks should not be considered as a final IPv6 network architecture. The use of overlay tunnels should be considered as a transition technique toward a network that supports both the IPv4 and IPv6 protocol stacks or just the IPv6 protocol stack .

5.5 : GRE/IPv4 Tunnel Support for IPv6 Traffic

IPv6 traffic can be carried over IPv4 GRE tunnels using the standard GRE tunneling technique that is designed to provide the services necessary to implement any standard point-to-point encapsulation scheme. As in IPv6 manually configured tunnels, GRE tunnels are links between two points, with a separate tunnel for each

link. The tunnels are not tied to a specific passenger or transport protocol, but in this

case carry IPv6 as the passenger protocol with the GRE as the carrier protocol and

IPv4 or IPv6 as the transport protocol.

The primary use of GRE tunnels is for stable connections that require regular secure

communication between two edge routers or between an edge router and an end system. The edge routers and the end systems must be dual-stack implementations.

GRE has a protocol field that identifies the passenger protocol. GRE tunnels allow

Intermediate System-to-Intermediate System (IS-IS) or IPv6 to be specified as a passenger protocol, which allows both IS-IS and IPv6 traffic to run over the same tunnel. If GRE did not have a protocol field, it would be impossible to distinguish whether the tunnel was carrying IS-IS or IPv6 packets. The GRE protocol field is why

it is desirable that you tunnel IS-IS and IPv6 inside GRE.

5.6 : GRE/CLNS Tunnel Support for IPv4 and IPv6 Packets GRE tunneling of IPv4 and IPv6 packets through CLNS networks enables Cisco CLNS Tunnels (CTunnels) to interoperate with networking equipment from other vendors. The optional GRE services defined in header fields, such as checksums, keys, and sequencing, are not supported. Any packet received requesting such

services will be dropped.

5.7 : Automatic 6to4 Tunnels

An automatic 6to4 tunnel allows isolated IPv6 domains to be connected over an IPv4 network to remote IPv6 networks. The key difference between automatic 6to4 tunnels and manually configured tunnels is that the tunnel is not point-to-point; it is point-to-multipoint. In automatic 6to4 tunnels, routers are not configured in pairs because they treat the IPv4 infrastructure as a virtual nonbroadcast multiaccess (NBMA) link. The

IPv4 address embedded in the IPv6 address is used to find the other end of the automatic tunnel.

An automatic 6to4 tunnel may be configured on a border router in an isolated IPv6 network, which creates a tunnel on a per-packet basis to a border router in another IPv6 network over an IPv4 infrastructure. The tunnel destination is determined by the IPv4 address of the border router extracted from the IPv6 address that starts with the prefix 2002::/16, where the format is 2002:border-router-IPv4-address::/48. Following the embedded IPv4 address are 16 bits that can be used to number networks within the

site. The border router at each end of a 6to4 tunnel must support both the IPv4 and IPv6 protocol stacks. 6to4 tunnels are configured between border routers or between a border router and a host.

The simplest deployment scenario for 6to4 tunnels is to interconnect multiple IPv6 sites, each of which has at least one connection to a shared IPv4 network. This IPv4 network could be the global Internet or a corporate backbone. The key requirement is that each site have a globally unique IPv4 address; the Cisco IOS software uses this address to construct a globally unique 6to4/48 IPv6 prefix. As with other tunnel

mechanisms, appropriate entries in a Domain Name System (DNS) that map between hostnames and IP addresses for both IPv4 and IPv6 allow the applications to choose the required address.

5.8 : Automatic IPv4-Compatible IPv6 Tunnels

Automatic IPv4-compatible tunnels use IPv4-compatible IPv6 addresses. IPv4-compatible IPv6 addresses are IPv6 unicast addresses that have zeros in the high-order 96 bits of the address, and an IPv4 address in the low-order 32 bits. They can be written as 0:0:0:0:0:0:A.B.C.D or ::A.B.C.D, where “A.B.C.D” represents the

embedded IPv4 address.

The tunnel destination is automatically determined by the IPv4 address in the low-

order 32 bits of IPv4-compatible IPv6 addresses. The host or router at each end of an IPv4-compatible tunnel must support both the IPv4 and IPv6 protocol stacks. IPv4-compatible tunnels can be configured between border-routers or between a border-router and a host. Using IPv4-compatible tunnels is an easy method to create tunnels

for IPv6 over IPv4, but the technique does not scale for large networks.

IPv4-compatible tunnels were initially supported for IPv6, but are being deprecated. Cisco recommends that you use the IPv6 ISATAP tunneling technique.

Section 6 : IPV6 Network potential problems

6.1 : Poor IPv6 Network Performance:

Most applications on dual stack nodes will try IPv6 destinations first by default due

to the Default Address Selection mechanism. If the IPv6 connectivity to those

destinations is poor while the IPv4 connectivity is better , the IPv6 traffic experiences higher latency, lower throughput, or more lost packets than IPv4 traffic, applications will still communicate over IPv6 at the expense of network

performance. There is no information available to applications in this case to advise them to try another destination address. An example of such a situation is a node which obtains IPv4 connectivity natively through an ISP, but whose IPv6 connectivity is obtained through a configured tunnel whose other endpoint is

topologically such that most IPv6 communication is done through triangular IPv4 paths. Operational experience on the 6bone shows that IPv6 RTT’s are poor in such situations. An example of such a network is an enterprise network that has both IPv4 and IPv6 routing within the enterprise and has a firewall configured to allow some IPv4 communication,but no IPv6 ommunication.

6.2 : Security Problems in IPV6 over IPV4:

Enabling IPv6 on a host implies that the services on the host may be open to IPv6 communication. If the service itself is insecure and depends on a security policy enforced somewhere else on the network (such as in a firewall), then there is

potential for new attacks against the service.

A firewall may not be enforcing the same policy for IPv4 as for IPv6 traffic, which could be due to misconfiguration of the firewall. One possibility is that the firewall could have more relaxed policy for IPv6, perhaps by letting all IPv6 packets pass through, or by letting all IPv4 protocol packets pass through. In this scenario, the dual stack hosts within the protected network could be subject to different attacks than for IPv4.Even if a firewall has a stricter policy or identical policy for IPv6 traffic than for

IPv4 (the extreme case being that it drops all IPv6 traffic), IPv6 packets could go through the network untouched if tunneled over a transport layer. This could open the host to direct IPv6 attacks. It should be noted that IPv4 packets can also be tunneled, so this is not a new security concern for IPv6. Firewalls must be

deliberately and properly configured.

A similar problem could exist for virtual private network (VPN) software. A VPN could protect all IPv4 packets but transmit all others onto the local subnet unprotected. At least one widely used VPN behaves this way. This is problematic

on a dual stack host that has IPv6 enabled on its local network. It establishes its VPN link and attempts to communicate with destinations that resolve to both IPv4 and IPv6 addresses. The destination address selection mechanism prefers the IPv6 destination so the application sends packets to an IPv6 address. The VPN doesn’t know about IPv6, so instead of protecting the packets and sending them to the

remote end of the VPN, it passes such packets in the clear to the local network.

This is problematic for a number of reasons. The first is that if the node has a default IPv6 route, the packets will be forwarded off-link to an unknown destination.

Another is if no legitimate router is on-link and the node makes the on-link, the packets will simply be sent onto the local link to be potentially viewed by a node spoofing the destination. A third is if a rogue IPv6 router exists on-link. In that case the malicious node will simply be sent all IPv6 packets in the clear.

6.3 : Finding problems in TCP/IP using IPV6:

In this part I want to describe the techniques and tools that we can use to help identify

a problem at successive layers of the Transmission Control Protocol/Internet Protocol

(TCP/IP) protocol stack that is using an Internet Protocol version 6 (IPv6) Internet layer in Microsoft Windows XP , Windows Server 2003 or Windows Vista.

Depending on the type of problem, we might do one of the following:

-Starting from the bottom of the stack and move up.

-Starting from the top of the stack and move down.

The following sections are organized from the top of the stack and describe how to:

-Verify IPv6 connectivity

-Verify Domain Name System (DNS) name resolution for IPv6 addresses

-Verify IPv6-based TCP connections

We can also use Network Monitor to capture IPv6 traffic Although not specified in the following sections, to troubleshoot many problems with IPv6-based communications. Network Monitor is provided with Microsoft Systems Management Server and as an optional network component with Windows Server 2003. However, to correctly interpret the display of IPv6 packets in Network Monitor, we must have

detailed knowledge of the protocols included in each packet.

7.3.1 : Manage Configuration

To manually configure IPv6 addresses, use the netsh interface ipv6 set address command. In Windows Vista, we can manually configure IPv6 addresses from the properties of the Internet Protocol Version 6 (TCP/IPv6) component, available from the Network Connections folder. In most cases, we do not need to manually configure

IPv6 addresses because they are automatically assigned for hosts through IPv6 address auto-configuration.

Also to make changes to the configuration of IPv6 interfaces, we use the netsh interface ipv6 set interface command. To add the IPv6 addresses of DNS servers, use the netsh interface ipv6 add dnsserver command.

7.3.2 : Verify Reachability

To verify reachability with a local or remote destination, try the following:

“Check and flush the neighbor cache” . Similar to the Address Resolution Protocol (ARP) cache, the neighbor cache stores recently resolved link-layer addresses. To display the current contents of the neighbor cache, use the netsh interface ipv6 show neighbors command.

Section 7 : Conclusion

There are some of mechanisms for network administrators to transition their networks

from IPv4 to IPv6. The transition technologies I have presented are robust to slowly and incrementally transitioning groups of networks, as well as mixed protocol support of hosts within individual networks.

My recommendation is using tunneling IPV6 over IPV4 as much as possible to Simplify communications between IPv6 hosts.

I recommend first using tunneling to support both IPv4 and IPv6 applications, then slowly transitioning to pure IPV6 infrastructure. I believe this gradual process will support legacy systems until they are totally replaced, and this will ready the intranet for an IPv6 internet by the time of IPv4 address exhaustion.

Microsoft has more software that has no IPv6 support, but alternatives are available and everything still works on IPv4. It will take some time before everything has IPv6 support, until than both IPv6 and IPv4 can coexist together without any problems. Therefore it is advisable to implement IPv6 as much as possible,

because sooner or later the migration from IPv4 to IPv6 has to be made. Important when deciding to implement IPv6 is to plan everything very carefully. Especially when it comes to services it is important to know whether or not the services installed and configured in your situation are capable of handling IPv6.

Internet service providers may wait till there are enough IPv6 applications to deploy IPv6 networks, and application developers may wait for the IPv6 network to be deployed first. It is up to servers and application developers to take

more and more IPv6 into consideration and also all the business sectors to consider migrating to IPv6, and not waiting for others to be the firsts.

Of course, if everyone waits until the last minute, it could end up costing much

more not just to engineer the transition, but in the cost of the disruption to what has become a crucial part of our economic and social infrastructure.

As I wrote a common dual-stack migration strategy is to make the transition from the

core to the edge. This involves enabling two TCP/IP protocol stacks on the WAN core

routers, then perimeter routers and firewalls, then the server-farm routers and finally

the desktop access routers. After the network supports IPv6 and IPv4 protocols, the

process will enable dual protocol stacks on the servers and then the edge computer Systems.

In my opinion it is not difficult to implement IPv6 in an IPv4 environment and if there

are any hesitations left, this report shows that migration can go without difficulties.

The transition from IPv4 to IPv6 will be a larger task for the industry. It will affect nearly all networked applications, end-systems, frastructure systems, and network architectures.

The conversion to IPv6 has no specific timeline.

However, as noted upper, the rate of IPv4 address using is rapidly decreasing.

Section 9 : References

[1] Borella, M.; Grabelsky, D.; Lo, J.; Taniguchi, K. Realm “Specific IP Protocol Specification.” . IJCSNS International Journal of Computer Science and Network Security .http://tools.ietf.org/html/rfc3103 March 2007

[2] Sawant, A. ” IPv6 Features and Migration from IPv4.” In Bechtel Telecommunications Technical Journal, January 2004. from www.bechteltelecoms.com/docs/bttj_v2/Article8.pdf

[3] T. Chown.” Considerations for IPv6 Tunneling Solutions.”. International Journal of Foundations of Computer Science (IJFCS).April 2004.University of Southampton

[4] China Internet Information Center. “Statistical Survey Report on the Internet Development in China.”. from http://www.cnnic.net.cn/uploadfiles/pdf/2007/2/14/200607.pdf January 2007

[5] S. Daniel Park, “IPv6 Tunnel End-point Automatic Discovery Mechanism”. IJCSNS International Journal .(Sep 2004).

[6] Nevil Brownless, NeTraMet, .” Observations of IPv6 traffic on a 6to4 relay”

IJCSA, International Journal of computer science and application . http://portal.acm.org/citation.cfm?id=1052821 .(Jan 2005)

[7] Daniele Muscetta , “ Connecting to an IPv6 Tunnel Broker ” . IJCSNS International Journal . (2005)

[8] Wright, A. “ Internet Adoption Slowing But Dependence on It Continues to Grow. “. from http://www.ipsosna.com/news/pressrelease.cfm?id=3030 March 29, 2006

[9] Barlow, J. “ IPv6 HandsOn “ IJCSA, International Journal of computer science and application . December 2006

[10] Tsirtsis, G.; Srisuresh, P.” Network Address Translation Protocol Translation (NATPT).” In InternetDraft, .Retrieved December 2006 from http://tools.ietf.org/html/rfc2766

[11] Borella, M.; Montenegro, G. “Address Sharing with EndtoEnd Security. “ In the Proceedings of the Special Workshop on Intelligence at the Network Edge, December 2006 from https://www.usenix.org/publications/library/proceedings/ine2000/full_papers/borella/borella_html/rsipusenix.html

[12] Borman, D.; Deering, S.; Hinden, R. “ IPv6 Jumbograms.” . IJCSNS International Journal . December 2006 from http://tools.ietf.org/html/rfc2675

[13] Carpenter, B.; Moore, K.” Connection of IPv6 Domains via IPv4 Clouds.”

International Journal of Foundations of Computer Science (IJFCS) Decemeber 2006 .

[14] Hupprich, L.; Bumatay, M. Global Internet Population Grows an Average of Four Percent YearOverYear. Nielsen//NetRatings. March 2007 from http://phx.corporateir.net/phoenix.zhtml?c=82037&p=irolnewsArticle&ID=538993&highlight=

[15] [RFC4607] H. Holbrook and B. Cain, “Source-Specific Multicast for IP”, Cisco RFC 4607, August 2006.

[16] IPv6 Task Force, U.S. Department of Commerce.” Technical and Economic Assessment of Internet Protocol Version 6 (IPv6).” January 2006. from http://www.ntia.doc.gov/ntiahome/ntiageneral/ipv6/final/ipv6final.pdf

[17] Metz, C.; Hagino, J. “ IPv4Mapped Addresses on the Wire Considered Harmful.” International Journal of Foundations of Computer Science (IJFCS), December 2006 .

[18] Professor Peter Kirstein, Dr. Tim Chown “Why a new Internet Protocol?”, UKIPV6 Task Force Journal . (2006).

[19] Pekka Savola. CSC/FUNET, Finland .

” Observations of IPv6 Traffic on a 6to4 Relay. “IJCSA, International Journal of computer science and application. (Sep 2007).

[20] Microsoft, “ Microsoft’s Objectives for IPV6 Tunneling” http://technet.microsoft.com/en-us/library/bb726951.aspx (2007),

[21] [RFC4795] B. Aboba, D. Thaler, L. Esibov, “Link-local Multicast Name

zesolution (LLMNR)”, HongKong Computer Society journal. January 2007.

[22] Raymond A. Plzak, “ARIN Board Advises Internet Community on Migration to IPv6.” International Journal of Foundations of Computer Science (IJFCS). (May 2007)

[23] Jeroen van Nieuwenhuizen ( 2007 ). Setting up IPv6 . Project Phoenix The Legend

M. Rahman, Ph.D, Andrew Schaumberg (2007). Transitioning Networks from IPv4 to IPv6.University Plaza, Platteville, USA .

[24] IANA. “ IPv4 Address Report.” International Journal of Foundations of Computer Science (IJFCS) . (March 2007) from http://www.potaroo.net/tools/ipv4/index.html

In order to maintain you car in a good shape, to offer you the safety as well the performances it was designed for in the first place, taking care of your vehicle’s transmission is a vital thing you should take care of. Modern cars have very complex drive trains, and the transmission being one of the most important elements of it, repairing it because of the in-proper use can be very costly. The most serious operations on a car’s drive train can only be executed in specialized shops, but the casual maintenance operations you can make them yourself.

The biggest enemy of the vehicle’s transmission is heat. There are many causes for the heating of the transmission’s elements, and many are related to operating your car under difficult conditions. Racing with your vehicle, towing a load, or repeatedly putting it in drive and reverse for exiting heavy snow or mud can contribute to the overheating of its ensembles.

If you often are forced to operate your car under these circumstances, you can benefit greatly from adding additional cooling to your transmission. Such a cooler will be mounted on the radiator and it will cool the transmission fluid. Because many SUV owners use them to tow heavy vehicles, they came equipped from the factory with such auxiliary transmission coolers.

In the following paragraph you will find a series of tips about properly maintaining your car’s transmission.

The most important aspect is to have your transmission fluid checked on a regular basis. Also check for its color. It should be red. If it had turned brown or it has a burnt smell should be changed at once.

Before buying transmission fluid, check with your car’s owner’s manual to se the exact type the manufacturer recommends. Never mix two different types of fluid of fluids coming from different manufacturers.

The recommended period to replace it is every 2 years or every 24,000 miles, which ever condition occurs first.

When you want to put your car in reverse, come to a complete stop first. Changing from drive to reverse while the vehicle is still moving will harm your transmission.

In order to protect vital transmission elements, put the cark into park after you have pressed the brake pedal and pull the emergency brake. By doing this, less stress is applied to the drive train.

Always change gears from park to drive only when your engine is at idle.

When towing a very heavy load or when you are climbing abrupt terrain, be sure to disengage the overdrive feature, if your car is equipped with such a option, as it will prevent the car from repeatedly changing gears from and to overdrive. Overdrive is the highest gear in the transmission and it used to allow that vehicle to run at highway cruising speeds with a reduced revs, in order to mainly save fuel and reduce noise. If the automatic gear in your car has a 4-speed transmission with overdrive, the overdrive refers to the 4th gear. The same is with cars with 5-gear automated transmission with overdrive. There is the possibility to have a smaller car, with a 4 or 5 way automated transmission, but without the overdrive function.

You spend thousands of dollars on buying the vehicle, but now you are just flushing that hard earned money by being careless. If you feel that you have been doing your part for your car by taking it for servicing twice a month, then let me put a check there. This is not enough… a few tips would definitely help in a smoother drive and longer lifeline of the car. Follow these tips that include some Do’s & Dont’s…

1. The Right Start Obviously it is something very common but most of us never give it a thought. Turning on the car accessories before the car starts, wears down the engine. While starting the car, just turn off different accessories like music system, climate control, air conditioner or climate controller, etc. Increase the lifeline of the car – Don’t Put Pressure On The Engine.

2. ‘Warm Up’ – But The Right Way During Winters, you must be revving the engine to warm up the car. You never cracked your brain to the thought that when you rev the engine, the oil has not reached the system thus forcing the engine to work without any kind of lubrication. Rather than warming up your car, you are just heating it. So next time, you intend to warm up your darling vehicle, do it the right way – Let It Sit Idle For Around 60 Seconds.

3. Use The Emergency Brake It is always advisable to use these emergency brakes that are commonly known as hand brakes or parking brakes. These would help in keeping the vehicle motionless without putting the pressure on the parking pawl and consequently on the transmission system. Why trouble the transmission of the car, when you can do without it easily. Therefore remember – Always Use Parking Brakes.

4. Let The Car Stop Completely & Then Drive This is what we always do and that is right from the parking we shift to drive before the car stops moving backward. I hope you would be honest to admit it. This will ruin your vehicle. Remember to let the car stop from going backward before you start driving. If you don’t obey this, you are risking the gears, drive shafts and the entire transmission of the car. Avoid a worn out transmission – Let the car stop before shifting to drive.

5. Listen to Your Car’s Needs Paying immediate attention can reduce the aggravating problem. I am not suggesting you to be tensed about the driving – rather just be alert to any unusual sound of the car.

A small check yourself would help you identify the cause easily.

Hybrids are hot nowadays. Hybrid cars use 2 engine, one for the traditional fuel, while the other uses the energy from a rechargeable battery. The recent years had car manufacturers scrambling to rollout a entire spectrum of hybrid Cars from the most popular brands to the more obscure. What then is or guarantee that we are protected from too much hype, instead of an honest advertising?

Hybrid Cars according to Consumer Reports.

There are many hybrid cars information available, especially on their features, engine specifications, designs, colors and much other dizzying information. Information from the manufacturer’s website are also good source of needed preliminary knowledge n hybrid cars. But such sites are good for information gathering, and much more comparison activities should be done before buying your hybrid cars.

The Pros. “These hybrid systems have been very reliable,” declares David Champion, senior director of Consumer Reports’ auto test center, influential consumer survey. This center, collects individual consumer reports on hybrid cars, and uses the statistics to come up with a talk paper. It also accords “awards” to car with the best review report. However, some automobile experts and analysts have criticized the hybrid car powertrain, as flamboyant in that two engines are being used for one purpose. Consumer Reports on the other hand, disagreed. Champion explained that the electric motor adds power to the engine. Prior to the award proper, Consumer Report conducts a testing, by applying some actual expectations of consumers to hybrid cars. The Accord hybrid for instance, achieved superior fuel efficiency unsurpassed by its conventional counterparts.

The Cons. But as in other endeavor, consumer reports on hybrid cars also impartially advises from a different perspective. An alternative consumer view from the same center posed the question: “Considering a hybrid car? Don’t rush out to the dealership just yet.” The center asserts that they are not against the protection of environment and it also insisted that they are supportive for burning less fossil fuel. Their concerns, essentially stems from some financial experts arguments that hybrid drivers may be paying a higher price for an automobile that offers marginally better fuel efficiency than the other economy cars already on the road.

These are but only few of the literature that deals with consumer reports on hybrid cars. It is, ultimately, depends on the consumer, to peruse on many information regarding hybrid cars.

Visit my site for more details on Environmentally Friendly Cars and more.

With the cost of both recreational and service vehicles consistently on the rise, in addition to the escalating cost of fuel, purchasing high quality parts that protect and extend the life of your transmission can prove to be a tremendously worthwhile investment. Mag Hytec is an industry leading manufacturer of superiorly designed transmission pans and differential covers that can help eliminate costly repairs and extend the life of your transmission.

Those who own and operate vehicles that are subject to heavy usage know how important it is to properly maintain their vehicles in order to keep them in good working order and avoid costly repairs. The transmission, also commonly referred to as the gearbox, of any vehicle is one of the many hard working and critically important vehicle parts. With heavy usage it is normal for axles and transmission parts to no longer perform at optimal levels and simply wear out. Transmission pans and differential covers make it possible to maintain the original performance standards of your transmission and increase its functional life span.

These parts are highly regarded in the automotive industry. The differences between Mag Hytec products and those provided by the competition are both aesthetic and functional. Mag Hytec differential covers and transmission pans are both manufactured in A356-T6 aluminum and enhanced with a textured, jet black powder coat finish. Machined cooling fins ensure appropriate temperatures are maintained while magnetic drain plugs filter out any metallic debris that could potentially become embedded within the transmission fluid and reduce its effectiveness.
From differential covers to transmission pans, their heavy duty construction and intuitive design are hard to beat and have always been extremely beneficial.

Although there are various types of transmissions, they all operate according to the same basic principle. The primary function of a vehicles transmission is to synchronize power and speed in order for the vehicle to operate efficiently and effectively under various operating circumstances and terrain conditions. This is true of both automatic and manual transmissions of varying sizes and gears. As a vehicles speed is increased the engine is required to spin more rapidly, increasing the amount of power generated in order to move the vehicle and anything that may be in tow capably. The engine does not require as much power when it is being driven at a consistent speed on a primarily level surface. The transmission regulates the ratio between the speed and power required by the engine under different driving circumstances. It will utilize a higher ratio when a lot of power is required at reduced speeds, as would be the case when climbing a hill, and a lower ratio when more speed and less power is necessary, such as during highway cruising.

A constant and safe operating temperature is maintained through the use of transmission fluid which lubricates and cools moving parts. The heat generated throughout the normal course of operations causes the transmission fluid to break down and requires regularly scheduled replacement of the fluid. In addition, the heat generated throughout the course of normal usage causes the transmission parts to wear down, resulting in the mixture of this metallic debris with the transmission fluid. The magnetized transmission covers and pans attract and filter out the debris, resulting in transmission fluid that runs cleaner and extends the life of the transmission and its components.

The construction of Mag Hytec transmission components and products, including their transmission covers and differential pans, are designed to compliment and enhance the cooling process required to keep the engine and transmission running at the ideal temperatures regardless of particular circumstances.