I'm having a bit of a problem with the "cname" option in Dnsmasq. I have some 
configuration options like these in dnsmasq.conf, where "host1" and "host2" 
have IPv4 addresses from DHCP:


This works well for A lookups on git.example.com and nas.example.com, but the 
cname options are ignored for AAAA lookups. I think this is by design, since 
the man page says the target of a cname must be known or it will be ignored. 
(Although, maybe this is unintentional in this case? It does seem like a bit of 
a bug for a name to *sometimes* be a CNAME, depending on the request type.) 
Unfortunately, it's causing problems when the AAAA queries are forwarded 
upstream, but I'm not sure how to fix it since these servers don't have IPv6 

For some background:

The goal is to provide something like split-horizon DNS. Host1 and host2 reside 
behind NAT. On public DNS, philadelphia.example.com resolves to their public 
address, with git.example.com and nas.example.com both being CNAMEs to that 
name. But within the LAN, git.example.com and nas.example.com should be CNAMEs 
to their local names.

The problem is, some clients cache their DNS requests. When these clients send 
a AAAA request, it gets forwarded upstream and they end up caching the public 
CNAME record. Then, they use the (incorrect) cached CNAME for A requests, too.

Is there a good way to solve this?


Dnsmasq-discuss mailing list

Reply via email to