Add IP-FORWARD-MIB to the default snmp.yml

[satwell]

Could IP-FORWARD-MIB be added to the modules available in the default snmp.yml config? This provides the routing table for the device.

Why is the useful? I have some Mikrotik routers using OSPF, and I'd like to set up alerts to fire when devices aren't using the expected routes. E.g., if they switch to using a failover link instead of a primary.

[bastischubert]

@satwell if you like, you can hand in a PR for a new module with the necessary fields that would be needed for such monitoring use-case. https://github.com/prometheus/snmp_exporter/tree/main/generator#file-format explains how such a module definition needs to be created in order to work with the snmp-exporter generator.