[nsd-users] Fixed IPv6 Source Address for UDP Connections

Yuri Schaeffer yuri at NLnetLabs.nl
Mon Jul 12 07:28:44 UTC 2010

Hello Matthias-Christian,

> However, sometimes the DNS server replies from a different address
> (the client queried 2001:db8:1::2 and got a reply from 2001:db8:1::2),
> because the DNS server seems to pick an address randomly. This is
> possible because UDP is stateless (with TCP it works).

When you don't specify an interface to bind the OS will select one for
you. The tunnel interface may be confusing it. Make sure your nsd.conf
looks similar to this:

        ip-address: 2001:db8:2::1
        ip-address: [your ipv4 address]


Yuri Schaeffer
NLnet Labs

More information about the nsd-users mailing list