Emergency UNIX and Linux Support

This has never happened before, but my laptop is now unable to access any remote servers. I have tried with 3 independent servers that I have access as recently as last week.

I am not asked for my password,

Code:

home:~ x$ ssh -v -p22 user@server
OpenSSH_5.2p1, OpenSSL 0.9.7l 28 Sep 2006
debug1: Reading configuration data /etc/ssh_config
debug1: Connecting to server [194.57.168.xx] port 22.
debug1: connect to address 194.57.168.xx port 22: Operation timed out
ssh: connect to host serverport 22: Operation timed out

What might I have done wrong? I cleared the known_hosts file after I started having this problem. I can see that ssh_config is probably what is causing me this problem

When I ping any of the remote servers I get no response and on cancelling the request I have 100% packet loss.

Any help appreciated!!!!!

looks more like a network problem... if you can not ping the server, you most certainly can not ssh to the server...

As Duke mentioned, it's certainly a network problem. Could be an issue due to network configuration of the laptop or could be possible network admin changed VLANs behind your back and forgot to enable routing among them.

I would rather need a clear picture of your network and the network config of the OS you are running to conclude something.

Greetings,

As has been previously mentioned, more information about your network topology would probably help in troubleshooting this. That being said, let me toss out a couple situations that might apply to your problem, or if not, maybe they can help get you thinking in the right direction.

First, just because a ping does not succeed does not mean there is a problem. If you are on different subnets or networks, that might be normal. Most networks block ICMP (ping) traffic from entering their networks if not being more restrictive. If however, you have been able to successfully ping before, and now you cannot, then it would seem that there is indeed a network problem and you should contact someone on your network team.

Second, most UNIX and Linux servers use TCP_WRAPPERS to protect network services on their server. This means that in the hosts.allow file, there is most likely an entry allowing you and your computer access via SSH. This is done by allowing your IP address (or subnet perhaps) or hostname access to the system. If by some chance the IP address on your PC has changed (say, by DHCP) that could cause the error you see. Or if they are using a hostname to allow access, it could be a DNS problem if the server you are connecting to cannot perform a reverse DNS lookup on your IP. So there are a couple things to check, make sure your IP hasn't changed and make sure that reverse DNS is working properly for that IP. Plus, the server you are connecting to could be having DNS problems even if DNS in general is functioning on your network.

I hope this helps, please post an update with more information if you are still having problems, or if you find the solution.

Thanks,

Laz

As you get error with given command and your SSH command is user@server (I hope it is some server name not IP).

So it is trying to connect to 194.57.168.xx .
Now if ping failed it could that server is down/network is down or Server has ping disabled on n/w or on server or even from your laptop f/w.

Do some basic check
1. Check if you internet connection is good
2. Check if you can connect to another server on same n/w
3. if you have internet working . then try connecting via another server. Some times routes are set bad or shortest connection is down.
4. Call some one on Datacenter and check if server is up or not.
else .. we have a Road block.

Code:

home:~ x$ ssh -v -p22 user@server
OpenSSH_5.2p1, OpenSSL 0.9.7l 28 Sep 2006
debug1: Reading configuration data /etc/ssh_config
debug1: Connecting to server [194.57.168.xx] port 22.
debug1: connect to address 194.57.168.xx port 22: Operation timed out
ssh: connect to host serverport 22: Operation timed out

My hunch: firewall is blocking it.

not necessarily, firewall could block ICMP but pass ssh.