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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 (

The ssh -v output doesn't provide any helpful information either:

username@$ ssh -v username@ -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 [] 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?

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have you tried it from a differeny PC on the same network? To your knowledge were there any previous failed authentications from tis host? – Argusvision Oct 19 '12 at 0:30
hm... it's just the one workstation. So the problem is likely with the workstation (all of a sudden!). I can't imagine what though... – Logos Oct 19 '12 at 15:59
Check your logs for SSH regarding failed authentication, or restricted/blocked Hosts or RSA's. I might be of the mark but I'm pretty sure multiple failed authentication can barr a host. – Argusvision Oct 20 '12 at 0:24
@Argusvision: which logs would those be, then? I posted the data from the logs I thought relevant. – Logos Oct 20 '12 at 18:25

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