SSH on Multiple ports Fedora Core 4

John Gallagher john.gallagher at ciosystems.com
Mon Nov 28 21:47:00 UTC 2005


I have created a separate config file for SSH to run and listen on another
port (for example: 5000 RSA connections only).  I created another init
script called sshd-ext in /etc/init.d (Minor Modifications see file below).
I created file to call the new config in /etc/sysconfig/sshd-ext.

All seems to work fine except I get errors in the security logs.  Which I
have seen from others post on the Fedora forum.

Nov 28 12:26:58 vpn sshd[26691]: error: Bind to port 5000 on 0.0.0.0 failed:
Address already in use.
Nov 28 12:35:42 vpn sshd[26691]: Received signal 15; terminating.

I edited the conf file and specified the IP Address of the interface to use
for this config:

Port 5000
#Protocol 2,1
ListenAddress 10.200.16.10
#ListenAddress 0.0.0.0
#ListenAddress ::

I verified the original sshd_confid was only listening on 0.0.0.0 and not ::

The problem is ssh seems to use the same PID for both processes and always
wants to bind on port 22 for some reason.  If I restart one of the processes
it can and sometimes does kill the other process.  

service sshd restart will kill the process started as sshd-ext.
 
I also run the same config on FC1 and I have do not have these issues.
 
See version and intit scripts below:

[root at vpn root]# rpm -qa |grep ssh
openssh-askpass-3.6.1p2-34
openssh-3.6.1p2-34
openssh-clients-3.6.1p2-34
openssh-askpass-gnome-3.6.1p2-34
openssh-server-3.6.1p2-34
[root at vpn root]#

[root at vpn root]# cat /etc/init.d/sshd-ext
#!/bin/bash
#
# Init file for OpenSSH server daemon
#
# chkconfig: 2345 55 25
# description: OpenSSH server daemon
#
# processname: sshd
# config: /etc/ssh/ssh_host_key
# config: /etc/ssh/ssh_host_key.pub
# config: /etc/ssh/ssh_random_seed
# config: /etc/ssh/sshd_config
# pidfile: /var/run/sshd-ext.pid

# source function library
. /etc/rc.d/init.d/functions

# pull in sysconfig settings
[ -f /etc/sysconfig/sshd-ext ] && . /etc/sysconfig/sshd-ext

RETVAL=0
prog="sshd"

# Some functions to make the below more readable
KEYGEN=/usr/bin/ssh-keygen
SSHD=/usr/sbin/sshd
RSA1_KEY=/etc/ssh/ssh_host_key
RSA_KEY=/etc/ssh/ssh_host_rsa_key
DSA_KEY=/etc/ssh/ssh_host_dsa_key
PID_FILE=/var/run/sshd-ext.pid

do_rsa1_keygen() {
        if [ ! -s $RSA1_KEY ]; then
                echo -n $"Generating SSH1 RSA host key: "
                if $KEYGEN -q -t rsa1 -f $RSA1_KEY -C '' -N '' >&/dev/null;
then
                        chmod 600 $RSA1_KEY
                        chmod 644 $RSA1_KEY.pub
                        success $"RSA1 key generation"
                        echo
                else
                        failure $"RSA1 key generation"
                        echo
                        exit 1
                fi
        fi
}

do_rsa_keygen() {
        if [ ! -s $RSA_KEY ]; then
                echo -n $"Generating SSH2 RSA host key: "
                if $KEYGEN -q -t rsa -f $RSA_KEY -C '' -N '' >&/dev/null;
then
                        chmod 600 $RSA_KEY
                        chmod 644 $RSA_KEY.pub
                        success $"RSA key generation"
                        echo
                else
                        failure $"RSA key generation"
                        echo
                        exit 1
                fi
        fi
}

do_dsa_keygen() {
        if [ ! -s $DSA_KEY ]; then
                echo -n $"Generating SSH2 DSA host key: "
                if $KEYGEN -q -t dsa -f $DSA_KEY -C '' -N '' >&/dev/null;
then
                        chmod 600 $DSA_KEY
                        chmod 644 $DSA_KEY.pub
                        success $"DSA key generation"
                        echo
                else
                        failure $"DSA key generation"
                        echo
                        exit 1
                fi
        fi
}

do_restart_sanity_check()
{
        $SSHD -t
        RETVAL=$?
        if [ ! "$RETVAL" = 0 ]; then
                failure $"Configuration file or keys are invalid"
                echo
        fi
}

start()
{
        # Create keys if necessary
        do_rsa1_keygen
        do_rsa_keygen
        do_dsa_keygen

        echo -n $"Starting $prog:"
        initlog -c "$SSHD $OPTIONS" && success || failure
        RETVAL=$?
        [ "$RETVAL" = 0 ] && touch /var/lock/subsys/sshd-ext
        echo
}

stop()
{
        echo -n $"Stopping $prog:"
        killproc $SSHD -TERM
        RETVAL=$?
        [ "$RETVAL" = 0 ] && rm -f /var/lock/subsys/sshd-ext
        echo
}

reload()
{
        echo -n $"Reloading $prog:"
        killproc $SSHD -HUP
        RETVAL=$?
        echo
}

case "$1" in
        start)
                start
                ;;
        stop)
                stop
                ;;
        restart)
                stop
                start
                ;;
        reload)
                reload
                ;;
        condrestart)
                if [ -f /var/lock/subsys/sshd-ext ] ; then
                        do_restart_sanity_check
                        if [ "$RETVAL" = 0 ] ; then
                                stop
                                # avoid race
                                sleep 3
                                start
                        fi
                fi
                ;;
        status)
                status $SSHD
                RETVAL=$?
                ;;
        *)
                echo $"Usage: $0
{start|stop|restart|reload|condrestart|status}"
                RETVAL=1
esac
exit $RETVAL
[root at vpn root]#
 




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