There is a server that cannot be connected to via SSH (port 22). Please consider these three servers all running CentOS 5.x:
- server1 - SELinux enforcing
- server2 - SELinux permissive
- server3 - SELinux enforcing
- server1 can access server1 and server3 via SSH but not server2
- server2 can access server2 but not access server1 or server3
- server3 can access server1 and server3 via SSH but not server2
Since server2 can access itself via ssh, it seems that ssh is properly working. From server2, the following have been tested or verified.
- /etc/sysconfig/iptables has port 22 open, and is identical to the other servers.
- verified that openssh-server and openssh-client is installed
- verified that service sshd status is running with chkconfig on
- used netstat -ptan and netstat -nlpa to verify that sshd is running with a pid
- verified that SELinux is permissive
- even attempted to connect with the firewall turned off: service iptables stop
- reviewed various logs to determine if there is anything obvious that would not permit ssh access. Only can find messages that access is "Connection refused".
Is there anything else I should consider towards resolution, aside from upgrade to CentOS6 or are all the updates applied?