Cannot ssh in to remote machine
 

Hey all, my problem is fairly straight forward: I was able to log into a client's box remotely but I can't any longer. My computer and the remote are both CentOS 5.2. My putty session just hangs and eventually errors.

NOTES:
I remotely logged into their windows server and used putty to get into the linux box in question (from 10.0.0.3 ssh -> 10.0.0.2). Here's what I was able to dredge:

I used the 'last' utility to see the last time I was able to login from my home:
Sat May 2 19:04 - 19:25
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I attempted a simple telnet session from my home to their box:
echo 'helo' | telnet mail.domain.com 22
Trying www.xxx.yyy.zzz...
telnet: connect to address www.xxx.yyy.zzz: Connection timed out

If I change it to port 25 it works:
# echo 'helo' | telnet mail.domain.com 25
Trying www.xxx.yyy.zzz...
Connected to mail.domain.com.
Escape character is '^]'.
Connection closed by foreign host.
So port forwarding is not the issue.

I went to http://www.canyouseeme.org (from their windows box) for a sanity check though. This site reported that it was able to get through on port 22.
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nmap, iptables -L, and netstat -ant all show ssh as funtional.
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If I pick through some of the logs I see entries like this:
aaa.bbb.ccc.ddd used to map to mail.example.org.ccc.bbb.aaa.in-addr.arpa, but I put a call into the ISP a few months ago to correct this, now it's correct: aaa.bbb.ccc.ddd <=> mail.example.org (fwd/rev)
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I then vi ~/.ssh/known_hosts and removed the previous key from my server and saved. This didn't help - duh.
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When I saw the above I checked /etc/hosts.deny on the remote box: empty
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grep denied /var/log/audit/audit.log (nothing)
grep fail /var/log/audit/audit.log (a few things that looked appropriate)
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I tightened the first rule and added the second:
These rules both work on other servers. I copy/pasted them to avoid type-o's.

Then: 'service iptables restart' and still can't get in from home.
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When I tail -f various logs (/var/log/{message,secure,audit}) while attempting an ssh session the logs don't budge. It's like I'm not hitting the box at all. Again though, I was able to at one time.
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SELinux is fully functional by the way. Past greping the the audit log for failures I don't know what to do with SELinux (newb).
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The clients' router is a consumer grade actiontec dsl modem. I shut off remote management for both ssh and telnet. If these are on, you'll end up telnet/sshing into the dsl modem.

I re-checked the port forwarding on the device as well. Both 'advanced port-forwarding' and 'applications' are doing the same thing forwarding all TCP port 22 requests to 10.0.0.2. This works for me at my home so it seems good.
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At this point I'm drawing a blank. If there's anything else I'm missing please correct my troubleshooting.

Thanks in advance-
TT

RE: Cannot ssh in to remote machine
 

Update: I don't believe this is a routing or port-forwarding issue. I'm now noticing gazillions of these:
These messages stopped when I modified the firewall rules in the previous post. So, at least others were able to hit the machine :D NOTE: all time/date stamps are of course in epoch time. The last last attempt was: Wednesday, June 10, 2009 11:33:10 AM which seems about right. This is a great time converter by the way: http://www.epochconverter.com/

On a personal note: since Google crawls the web and caches sites like this I feel like I should put a shout out to the douche-bags @ Xeex XEEX-COMMUNICATIONS-2 for trying to jack my server. Nice try F-tards.

Cannot ssh in to remote machine
 

ok, I checked one of the other posts and found a work-around:

I was doing it like this:
ssh mail.domain.com
like I do with all of my other connections.

When I specify the user root I am prompted for a password.
ssh root@mail.domain.com
root@mail.domain.com's password:
Last login: Wed Jun 10 13:30:24 2009 from mail.example.org
then, of course, I am given a shell:
[root@localhost ~]#
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I'm not sure what causes this. Please let me know. For all of my other servers I only have to: ssh mail.domain.com


Thanks,
TT