README.md

ipsec-monitoring

A set of libreswan-compatible bash scripts for monitoring ipsec tunnel status (e.g. send mail when tunnel is down)

The script looks for the 'unrouted' indicator in the output of the 'ipsec status' command.

Setup using crontab:

Assuming repo is cloned to /opt/ipsec-monitoring, the scripts can be executed as follows:

All VPN tunnels:

Usage: /opt/ipsec-monitoring/monitor-all-tunnels.sh *MAIL ADDRESS*

Crontab:

*/1 * * * *     /opt/ipsec-monitoring/monitor-all-tunnels.sh [email protected] >> /var/log/ipsec-monitoring.log

A specific VPN tunnel

Usage: /opt/ipsec-monitoring/monitor-tunnel.sh *TUNNEL NAME* *MAIL ADDRESS*

Crontab:

*/1 * * * *     /opt/ipsec-monitoring/monitor-tunnel.sh CUSTOMER-1 [email protected] >> /var/log/ipsec-monitoring.log

Additional considerations

chmod +x /opt/ipsec-monitoring/monitor-all-tunnels.sh
chmod +x /opt/ipsec-monitoring/monitor-tunnel.sh

Logging

Log file /var/log/ipsec-monitoring.log could look like this:

** Monitoring check of all tunnels at Thu May  9 12:31:01 UTC 2024
Tunnel CUSTOMER-1 is still up
Tunnel CUSTOMER-2 is still up
Tunnel CUSTOMER-3 is now down, mail sent to *email_recipient*

** Monitoring check of all tunnels at Thu May  9 12:32:01 UTC 2024
Tunnel CUSTOMER-1 is still up
Tunnel CUSTOMER-2 is still up
Tunnel CUSTOMER-3 is now up, mail sent to *email_recipient*

I highly recommend log rotation.

Automatic mail upon new offline status

Subject:

(Monitoring) IPSec tunnel down on *host*: CUSTOMER-3

Body:

~ IPSec monitoring on *host*  ~
 The following tunnel is down:
000 "CUSTOMER-3": *left ip*...%any[@customer-3]===*right ip*; unrouted; eroute owner: #0