DNS lookup for IPv6 peers (Teredo & 6to4)

[niktarace]

Hello.

In Peers tab, peers with IPv6 (Teredo tunneling & 6to4) have no reverse DNS (name & flag).

Anyway the logic is pretty simple to extract the IPv4 address from IPv6 address, and then apply the DNS lookup like any IPv4 peer.

Teredo

Bits 96 to 127 contains the obfuscated IPv4 address. This is the public IPv4 address of the NAT with all bits inverted.

http://en.wikipedia.org/wiki/Teredo_tunneling#Teredo_IPv6_addressing

Ex.: 2001:0:d5c7:a2d6:109d:14fb:a9e1:5e3f

a9e15e3f XOR ffffffff = 561ea1c0 (hex-IP)

Then hex-IP is simply converted into dec-IP 86.30.161.192

DNS lookup: cpc1-ipsw1-2-0-cust447.5-4.cable.virginmedia.com|UK

6to4

http://en.wikipedia.org/wiki/6to4#Address_block_allocation

Ex.: 2002:59d4:d11e::59d4:d11e

59d4d11e (hex-IP) converted into dec-IP 89.212.209.30

DNS lookup: 89-212-209-30.dynamic.dsl.t-2.net|SI

NB: Convert and locate IP addresses

http://www.kloth.net/services/iplocate.php