slow ssh authentication
 

I installed 2 new Centos 5.2 boxes.

Both use Key authentication for ssh, both use the same sshd_config.
Same user and key even.

Making an ssh connection to one system logs me in immediately, the other one takes almost 30 seconds before I get my prompt. I went through all settings disabled iptables but can't see any reason why this is happening.

Any suggestions are appreciated.

I have a similar issue, using some ubuntu boxes as static IP boxes, caching packages to install across network. Some respond immediately on ssh, others take a few seconds, others take up to a minute. I'm resigned to it at this stage! I think it may have something to do with network latency at particular points.

I have moved this to Linux-Networking as you may get more responses there.

I don't think its latency as they are in the same IP subnet and physically on the same switch even, the path to each box is the same basically.

I found the reason, related to RDNS and in my resolv.conf I had typo in the IP of the DNS server listed first.

I'm happy you solved the problem, I must look at my boxes now!