rtmon

Save all network state changes to a file

$ sudo rtmon file path/to/file

$ sudo rtmon file link

rtmon [options] file path

rtmon monitors and records network state changes to a file. It captures link changes, address modifications, and routing table updates for later analysis.
The output can be replayed or analyzed to understand network configuration history.

file path

Output file for network state changes

Filter by change type (link, address, route)

Requires root privileges. Output file can grow large over time with frequent changes.

Part of iproute2 package, providing network monitoring and logging capabilities.

ip(8), ip-monitor(8)