IPv6 Address formate

[KR SHAH]

HI,

I read some document about IPv4 to IPv6 migration and In 6to4 translation, when IPv4 i.e. 192.168.99.1 is converted into IPv6, it shows IPv6 Address 2002:C0A8:6301::1/64. In this , the ::1 is what interface ID or else. and if interface ID then how interface id calculated.?

Thanks,

Kuntal

[Michael Vincent]

IPv6 addresses beginning with 2002::/16 are special '6to4' addresses (see:  http://en.wikipedia.org/wiki/6to4).

The 6to4 address is created by appending the hex version of the IPv4 address to the '6to4' prefix:

In your example:

2002:192.168.99.1::/64

2002:c0.a8.63.01::/64

2002:c0a8:6301::/64

The ::1 is simply the lower half 64-bits of the IPv6 address and can really be just about anything.  So it is indeed the "interface ID" but can be calculated from various means including statically assigned.

[KR SHAH]

HI,

Thanks michael. But How to define interface ID. in some document i read that last bits are calcaulated from MAC addresses but i am still confuse about interface ID. Can you elaborate in detail ?

Thanks again for providing infromation,