Change ssh port remotely

How to change ssh port *remotely*



0. yum -y install telnet-server

    Enable telnet under xinetd by editing /etc/xinet.d/telnet (from disable=yes to no)



service telnet
{
        flags           = REUSE
        socket_type     = stream
        wait            = no
        user            = root
        server          = /usr/sbin/in.telnetd
        log_on_failure  += USERID
        disable         = no
}


1. Create a new account telnet123

   Grant sudo or something to telnet123



2. Telnet to the server



3. Change sshd port from 22 to 2200



[root@dragon525 ~]# diff /etc/ssh/sshd_config*
13,14d12
<
< # Stanrdard port
16,19d13
<
< # vuhung 2011/08/10 ported changed to 2200
< Port 2200
<




4. Restart sshd: sudo /etc/init.d/sshd restart



5. Login with ssh, new port = 2200



6. Delete user: telnet123



7. Delete package telnet-server or disable telnet (see step 0), using ssh.