Compare BGP sent/received routes on different routers before/after maintenance

[jamesharr]

Is your feature request related to a problem? Please describe.
Compare BGP routes received on different peers.

Describe the solution you'd like
Say we have a peer on an MX router, R1, and we moved that peer to an IOS-XR router, R2. I'd like to compare routes sent/received from that peer before and after the maintenance.

Additional context
This is an SP-focussed feature to compare routes sent-to and routes received-from a BGP peer after migration.

This is probably a different user-story, but we'd like to be able to collect/investigate routes accepted vs routes received as well. Sometimes we're not accepting routes from a peer and I think we'd like to see that, but it's probably more related to our peers doing maintenance or us doing route-policy maintenance on the same router.

Thanks!