2011/07/07

An ISP uses 6to4 tunnel to serve as v6 DNS resolver

Strange ! WTT has rolled out native IPv6 service but it  does not want to feed native IPv6 connection to its own dual-stack resolvers but uses 6to4 tunnels for serving as v6 DNS resolvers.  I have the chance to read WTT's  IPv6 configuration guide and notice that for static configuration, users have to input the DNS resolver as "2002:d596:2a92:1:71:53::". This is a 6to4 tunnel address.  Why not hook up the DNS resolver to its own native IPv6 link. 


















The extra path to a 6to4 gateway introduces delay and there is no acceptable guarantee of service. Bearing in mind the WTT 200M native IPv6 service is for corporate users, how comes WTT offers a lower class service for not providing truly v4/v6 DNS resolvers.

I think ISPs in Hong Kong should be careful not to rely on tunnels as part of its native v6 service

3 comments:

Anonymous said...

how to tell one is 6to4 tunnel address? thanks.

warrenkwok said...

2002::/16 is allocated 6to4 usage. In short, any IPv6 address with 2002 is 6to4 address.

Anonymous said...

thanks.
I visit your website every working day and learn a lot :)