Script to check the status of ipsec tunnels and refresh them if they're down. This should be run from cron every minute. To add monitoring on a tunnel, add a commented-out `monitor` line with the IP and port to use for establishing connection status. eg. `#monitor 172.17.105.80 9898` Adapted from a script posted by user "c b" on Strongswan [issu…

ipsec-monitor.sh

#!/bin/bash

function main()
{
    monitor_from_file $*
}

function monitor_vpn_ip_port()
{
    local CONN_NAME=$1
    local IP=$2
    local PORT=$3
    
    nc -w 10 -z $IP $PORT || ( \
        echo "$IP $PORT did not respond, resetting connection $CONN_NAME"; \
        ipsec auto --refresh $CONN_NAME;)
}

function monitor_from_file()
{
    local FILE=$1
    if [[ ! -e $FILE ]]; then
        echo "Can not find file $FILE."
        return 1
    fi

    # load the file into memory. Hope it's not too big. :)
    # -t strips out the newlines on each line.
    mapfile -t MYARRAY < $FILE
    # init local variable to contain the current connection name.
    local CONN=
    for LINE in "${MYARRAY[@]}"; do
        # Skip over any lines that have the comment at the very beginning.
        if [[ $LINE =~ ^\# ]]; then continue
        
        # Look for a line that looks like this which defines a VPN connection:
        # conn CONNECTION-NAME
        elif [[ $LINE =~ ^conn[\ ]  ]]; then
            # extract the part after the "conn " to get the name.
            CONN=`echo $LINE | sed 's/^conn //'`

        # Look for a line where we have the commented 'monitor' keyword.
        # Example:         #monitor 172.17.105.80 9898
        elif [[ $LINE =~ \#monitor ]]; then
            # Remove everything from the beginning up to and including the "#monitor "
            IP_PORT=`echo $LINE | sed 's/^.*#monitor //'`
            printf "`date` monitoring $CONN \t $IP_PORT\n"
            # IP_PORT should be space delimited and hence should work as separate parameters.
            monitor_vpn_ip_port $CONN $IP_PORT

        # if we have a blank line, that ends any connection configuration.
        elif [[ $LINE =~ ^$ ]]; then
            CONN=
        fi
    done
}


# now start running the script by calling main() with all parameters.
main $*

Hello,

thank you for sharing this script. I've been using it on a few projects

I'd like to point out that depending on the system the ipsec command may not be available when the script is run from CRON, due to the $PATH variable being redefined to the default value of the system. And as such it's advisable to set $PATH on the top of the script according to your configuration or to use the full path to the ipsec command,

@dareenzo

If you just add the following to the top of your crontab file, you won't need to adjust the script.

SHELL=/bin/bash
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=[email protected]

Its the same as any other crontab file, if you want a different set of paths or different users to get the cron mails, then you need to do this.

https://www.centos.org/docs/5/html/5.2/Deployment_Guide/s2-autotasks-cron-configuring.html

or read the man pages in most linux distros will give you some more example of variables that you can use.