How to send a connection notification to a router port?

Question

Network administration

Good afternoon,
Tell me in which direction to look for the answer. I would like to determine the moment when a router (ASUS RT-AC68U, Merlin) is connected from the WAN to a port (for example, to a forwarded port for watching a video camera or a home automation system, etc.) and send a notification (run a command, for example, send email or push notification to the phone (andriod), but this is not very important - just how to run the command on the router).
Thanks,
Dmitry

Answer 1

Didn't work with Asus. I'm writing from the point of view of other devices (Cisco, *nix)...
Standardly via SNMP (really, you need a second device or an additional service on the first one)? Install SNMP protocol. Periodically poll the router for status (raising a port, for example) and then perform a specific action.
You can go further and set traps for SNMP-Trap events, and the receiving side can parse the incoming OID and react further (send email, etc.).
Well, a custom path (did not check) -
https://github.com/RMerl/asuswrt-merlin/wiki/Sendi...
www.snbforums.com/threads/mail-when-vpn-connection...