[nsd-users] Cannot reach server from outside

[Stuart Henderson]

On 2023/10/04 20:55, Sagar Acharya via nsd-users wrote:
> Tried with ip-address option, it is not working.
> 
> I think ip-address binds to local ip address. Anyways localhost binds to the same ip as that of
> http, 0.0.0.0 , so everything is right from the system.

If your host has multiple addresses, binding to 0.0.0.0 will often
not do what you want for UDP. The source address of responses will
not necessarily be the same address as the query was sent to.
This is also described in the nsd.conf(5) manual in the description
of the "ip-address" option.

I suggest listing the specific IP addresses on which NSD will be
sent DNS queries.

Also use e.g. tcpdump to check that the queries are actually received
at your machine and not filtered upstream.

> How do I test udp from other network as dig tests over udp. Or can I dig over tcp?

"dig +tcp" will use TCP for the test, but TCP does not have the above
problem on multi-homed hosts.