When I was trying to start puppet, I had the following message:
[root@m03 puppet]# service puppet start
Starting puppet: dnsdomainname: Unknown host
dnsdomainname: Unknown host

Even though puppet started successfully. I checked my /etc/hosts file as puppet looks up DNS from there, everything looked fine. I also disabled selinux as that had been recommended on another blog. That might work for you, but didn’t do much for me.

Trying to sign my certificate was proving to be the same issue as well, rendering my puppet setup completely useless:
/usr/sbin/puppetd –waitforcert 30
dnsdomainname: Unknown host
dnsdomainname: Unknown host

I decided to check on the puppet master to see if my signature request had successfully hit the master:
puppet cert list –all | grep -i m03
…but no joy there.

When the dnsdomainname error comes up, the obvious answer is that the DNS is not resolving and it turns out that my puppet install is using an extra DNS entry to connect to the master. I compared an entry on another machine in /etc/resolv.conf, added that to the new machine; ran:
/usr/sbin/puppetd –waitforcert 30

…then the catalog ran successfully.