This is the weirdest problem I've ever had with trying to ssh into a server. Suddenly I can't ssh from my workstation to the server on the LAN. I can do so just fine from home, however. /var/log/auth.log isn't helpful, even with sshd logging set to VERBOSE:
Oct 18 17:08:35 servername sshd[4171]: refused connect from 192.168.0.7 (192.168.0.7)
The ssh -v output doesn't provide any helpful information either:
username@192.168.0.7:/home/username$ ssh -v username@192.168.0.30 -p ####
OpenSSH_5.3p1 Debian-3ubuntu7, OpenSSL 0.9.8k 25 Mar 2009
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to 192.168.0.30 [192.168.0.30] port ####.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /root/.ssh/identity type -1
debug1: identity file /root/.ssh/id_rsa type -1
debug1: identity file /root/.ssh/id_dsa type -1
ssh_exchange_identification: Connection closed by remote host
I don't have fail2ban running, and iptables doesn't show any funky rules. Anyone have any ideas or futher debugging tips?