Comment 5 for bug 389006

Another confirmation here.

It seems that dnsmasq doesn't want to listen on the correct interface. Here's the setup. The Ubuntu machine is connected to my router (192.168.1.1), which is connected to the internet. The Ubuntu box has address 192.168.144 on the side facing the router and internet, and 10.42.43.1 on the side that it is providing NAT to.

I ran some DNS lookups on the Ubuntu machine that is doing NAT. The first query is to the router (192.168.1.1), which is connected to the internet. The next three queries are to different interfaces on the the local machine. The only one that DOESN'T work is the interface that I'm actually interested in, which is 10.42.43.1 -- it's the address that the Ubuntu machine tells its clients is the DNS server.

# Querying the router OK
$ host ubuntu.com 192.168.1.1
Using domain server:
Name: 192.168.1.1
Address: 192.168.1.1#53
Aliases:

ubuntu.com has address 91.189.94.156
ubuntu.com mail is handled by 10 mx.canonical.com.

# Localhost interface OK
$ host ubuntu.com 127.0.0.1
Using domain server:
Name: 192.168.1.1
Address: 192.168.1.1#53
Aliases:

ubuntu.com has address 91.189.94.156
ubuntu.com mail is handled by 10 mx.canonical.com.

# Ubuntu machine's router-facing interface OK
$ host ubuntu.com 192.168.1.144
Using domain server:
Name: 192.168.1.1
Address: 192.168.1.1#53
Aliases:

ubuntu.com has address 91.189.94.156
ubuntu.com mail is handled by 10 mx.canonical.com.

# The client-side NAT interface of the Ubuntu machine NOT OK
$ host ubuntu.com 10.42.43.1
Using domain server:
Name: 10.42.43.1
Address: 10.42.43.1#53
Aliases:

Host ubuntu.com not found: 5(REFUSED)