Why can I ping a server but not connect via SSH?

Abe picture Abe · Oct 3, 2012 · Viewed 121k times · Source

When I ping my server, it responds:

user@localhost:~$ ping my.server
PING my.server (111.111.111.11) 56(84) bytes of data.
64 bytes from my.server (111.111.111.11): icmp_req=1 ttl=42 time=38.4 ms
64 bytes from my.server (111.111.111.11): icmp_req=2 ttl=42 time=50.0 ms
64 bytes from my.server (111.111.111.11): icmp_req=3 ttl=42 time=58.6 ms
^C
--- my.server ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 38.419/49.037/58.637/8.287 ms

but when I try to ssh (something that I always do, and have been doing for the past few hours on the same connection), it hangs:

user@localhost:~$ ssh my.server

http://speedtest.net says that my connection has 1.5 Mbps download and 0.4 Mbps upload speed.

Is there a reason that ssh hangs?


Results from suggestions provided in answers

from @nsfyn55

user@localhost:~$ telnetmy.server 22 
Trying 111.111.111.11...
Connected to my.server
Escape character is '^]'.
SSH-2.0-OpenSSH_4.3
Connection closed by foreign host.

from @vahid:

user@localhost:~$ nc -v -w 1 111.111.111.111 -z 22
nc: timeout cannot be negative

Answer

V H picture V H · Oct 3, 2012

ping (ICMP protocol) and ssh are two different protocols.

  1. It could be that ssh service is not running or not installed

  2. firewall restriction (local to server like iptables or even sshd config lock down ) or (external firewall that protects incomming traffic to network hosting 111.111.111.111)

First check is to see if ssh port is up

nc -v -w 1 111.111.111.111 -z 22

if it succeeds then ssh should communicate if not then it will never work until restriction is lifted or ssh is started