I have a L2TP Client setup for PPP, I want to make it so that it lives for 1 hour after no traffic is sent through it.

However it appears to be going down and instantly reconnecting. No matter what I've tried it keeps doing it so I assume something *somewhere* on the network is trying to reach the VPN connected side.

Is there any easy way to figure out what packets are causing the connection to get reconnected so I can trace the source?