ssh problem-big problem

alismayilov · 08-13-2011, 02:37 AM

Hello,

We have one user interface, there is some problem ssh to this server. Inside country (Azerbaijan) everybody can ssh to this machine. Outside of country, some people can ssh, some people not. Why?

[user@user-hp ~]$ ping ui.example.org
PING ui.example.org (ip) 56(84) bytes of data.
64 bytes from ui.example.org (ip): icmp_seq=1 ttl=128 time=114 ms
64 bytes from ui.example.org (ip): icmp_seq=2 ttl=128 time=114 ms
^C

--- ui.example.org ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1553ms
rtt min/avg/max/mdev = 114.307/114.332/114.358/0.339 ms
[user@user-hp ~]$ ssh user@ui.example.org
ssh: Could not resolve hostname ui.example.org: Name or service not known
[user@user-hp ~]$

What is the problem? Any idea?

norbert74 · 08-13-2011, 02:53 AM

Quote:

ssh: Could not resolve hostname ui.example.org

Can you log in with IP address ?

Code:

ssh user@[ip address]

alismayilov · 08-14-2011, 01:22 AM

No, I also could not connect with IP address.

siranjeevi · 08-14-2011, 04:00 AM

Hi,

Can you check if your local machine is opened with ssh port number .?.. Seems like your local machine is blocked with that outgoing port number.

alismayilov · 08-14-2011, 05:22 AM

ssh port is open. I also check online http://ping.eu/port-chk/ and it shows that: 22 port is open

snowweb · 08-14-2011, 05:41 AM

If we had a domain name or IP address, perhaps we could run traces?

Pete

Reuti · 08-14-2011, 06:15 AM

You can use telnet as a debugging tool. When you use telnet, you should get an output of:

Code:

$ telnet foobar.example.com 22
Trying 123.123.123.123...
Connected to foobar.example.com.
Escape character is '^]'.
SSH-2.0-OpenSSH_5.1

You can’t log in this way, but it checks whether you can access the port at all. If this is working, you can run ssh in verbose mode to check where it stops:

Code:

$ ssh -vvv foobar.example.com

Maybe it spots something.

alismayilov · 08-17-2011, 01:54 AM

Code:

[user@user-hp ~]$ telnet ui.example.org 22
Trying [ip]...
Connected to ui.example.org.
Escape character is '^]'.
^]

telnet> Connection closed.
[user@user-hp ~]$ ssh -vvv ui.example.org
OpenSSH_5.2p1, OpenSSL 0.9.8k-fips 25 Mar 2009
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to ui.azgrid.org [ip] port 22.
debug1: Connection established.
debug1: identity file /home/user/.ssh/identity type -1
debug1: identity file /home/user/.ssh/id_rsa type -1
debug1: identity file /home/user/.ssh/id_dsa type -1

So, after this nothing happen. So, what is the problem?

Reuti · 08-17-2011, 04:47 AM

Compared to the machines I have access to the lines:

Code:

debug1: Remote protocol version 2.0, remote software version OpenSSH_5.1
debug1: match: OpenSSH_5.1 pat OpenSSH*

are missing and an equivalent output with the telnet access is missing too. So I would check what is listening on port 22 - seems not to be an sshd but something else.

SKelem · 11-21-2011, 06:56 PM

I'm having trouble connecting to another computer on a local network.
I set up ssh on the server to use port 8383.
I can ping the server, but I can't telnet or ssh.

Any idea what's wrong?

Code:

% ping 192.168.111.175
PING 192.168.111.175 (192.168.111.175) 56(84) bytes of data.
64 bytes from 192.168.111.175: icmp_req=1 ttl=64 time=0.227 ms
64 bytes from 192.168.111.175: icmp_req=2 ttl=64 time=0.247 ms
^C
% telnet 192.168.111.175 8383
Trying 192.168.111.175...
telnet: connect to address 192.168.111.175: No route to host
% ssh -vvv 192.168.111.175:8383
OpenSSH_5.6p1, OpenSSL 1.0.0e-fips 6 Sep 2011
debug1: Reading configuration data /local/home/user/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
ssh: Could not resolve hostname 192.168.111.175:8383: Name or service not known

deep27ak · 11-21-2011, 10:45 PM

Quote:

Originally Posted by SKelem

I'm having trouble connecting to another computer on a local network.
I set up ssh on the server to use port 8383.
I can ping the server, but I can't telnet or ssh.

Any idea what's wrong?

Code:

% ping 192.168.111.175
PING 192.168.111.175 (192.168.111.175) 56(84) bytes of data.
64 bytes from 192.168.111.175: icmp_req=1 ttl=64 time=0.227 ms
64 bytes from 192.168.111.175: icmp_req=2 ttl=64 time=0.247 ms
^C
% telnet 192.168.111.175 8383
Trying 192.168.111.175...
telnet: connect to address 192.168.111.175: No route to host
% ssh -vvv 192.168.111.175:8383
OpenSSH_5.6p1, OpenSSL 1.0.0e-fips 6 Sep 2011
debug1: Reading configuration data /local/home/user/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
ssh: Could not resolve hostname 192.168.111.175:8383: Name or service not known

post the output of following commands

Code:

#netstat -ntlp | grep 8383

#cat /etc/hosts

#cat /etc/resolv.conf