With the development of internet technology is increasingly rapidly causing more and more internet users. But it added the internet user is not matched with the number of IPv4 addresses. So IETF issued a new IP protocol standard called IPng (Internet Protocol Next Generations) or also known as IPv6. IPv6 address format and has a different header with IPv4. So that IPv4 can not directly interconnect with IPv6. This can cause problems in the implementation of IPv6 in the IPv4 Internet network that has been installed. As solution to this problem required an implementation of IPv6 transition mechanism for IPv6. The aim of making this transition mechanism is so that IPv6 packets can be passed into the existing IPv4 networks or conversely.
Automatic Tunneling Mechanism functioning IPv6 packets pass through IPv4 network which has
there, without changing the IPv4 network infrastructure. Automatic Tunneling mechanism has a working principle encapsulates IPv6 packets with a header IPv4, then the package is immediately sent to the IPv4 network. The function of the encapsulation of IPv6 packets with IPv4 header is for the package can diroutingkan by routers IPv4. However with the addition of the IPv4 header is certainly going to increase in size, according to the packet length IPv4 header length is 20 byte. Accretion this package will also result in increased delay time the main paket. Question shipping of the implementation of IPv6 transition mechanism is the accretion time delay the process due to the length packets, the encapsulation process and the process decapsulation.
Automatic Tunneling Transition Mechanism has advantages :
- Easier in implementation.
In the implementation does not require much computer, simply use a computer
already there. especially for the gateway tunnel, the OS needs to be upgraded to the operating dualstack system which supports IPv6 and IPv4. - It’s easier in terms of configuration at the operating system.
In the configuration script is not needed a complex configuration script, simply by
tunnel interface configuration and configuration of routing tables only. - Does not require a server that serves the transition.
In the implementation does not require a special server that serves the transition mechanism, encapsulation and decapsulation is done in a tunnel between the gateway and point-to-point.
Weaknesses :
- Can not be implemented if the client is in transition NAT router.
- Will cause added delay (processing time).
- Vulnerable to DDOS attacks.
