topic Re: BGP show Local RIB before Import filters in General Topics

BGP show Local RIB before Import filters

MichielDetailleur — Mon, 14 Oct 2019 13:08:55 GMT

Hello,

After applying Import filters in BGP the Local RIB is reduced to a filtered set of routes advertised by peers.

However it seems to be impossible to see what the original set of advertised routes is. The peers are still advertising these routes, but there seem to be no methods in the GUI or CLI (show routing, debug routing ...) to see those advertised routes...

Is the only way to check this list really to disable all Import filters? And thus risking that unwanted routes will be installed? You could also first disable installing of routes (on the BGP General tab), but then you have a different problem...

Re: BGP show Local RIB before Import filters

JohnUrbanek — Wed, 03 Mar 2021 17:27:08 GMT

The ridiculous conclusion I came to was to brute-force it with a pcap. It's certainly before the filter gets applied... 🙂

# enable debug pcap for bgp debug routing pcap bgp on virtualrouter default # request bgp peer to resend all routes test routing bgp virtual-router default refresh peer lab01 # pcap name might be different view-pcap verbose++ yes debug-pcap bgp-vr-1.pcap # or SCP it elsewhere to view in wireshark scp export debug-pcap from bgp-vr-1.pcap to user@host:/optional/path # disable and delete the debug pcap for bgp when done debug routing pcap bgp off debug routing pcap bgp delete

Review the pcap preferably in wireshark and look for the prefixes. It works. Pretty asinine. There has to be a better way.

Re: BGP show Local RIB before Import filters

MichielDetailleur — Thu, 04 Mar 2021 08:29:52 GMT

Kudos for your mad skills! But not gonna accept this as a solution 🙂 Indeed there HAS to be a better way...