topic Re: Path monitored static route not removed from BGP RIB out table when path monitor dest. IP unreachable. in General Topics

Path monitored static route not removed from BGP RIB out table when path monitor dest. IP unreachable.

Ben-Price — Tue, 13 Jul 2021 02:18:04 GMT

Hi,

I have an issue where a Static route that is being path monitored and redistributed into BGP, is not removed from the BGP RIB out table when the monitored path is unreachable. The static route is still populated in the Palo Alto BGP rib out table and is also populated in the BGP peer route table.

Any ideas as to what may cause such an issue?

Re: Path monitored static route not removed from BGP RIB out table when path monitor dest. IP unreachable.

aleksandar.astardzhiev — Tue, 13 Jul 2021 08:30:46 GMT

Hi @Ben-Price ,

Without looking at your config, I would take a whild guess and assume that in BGP Redist. Rules you have put the network instead of using redistribution profile. Am I correct?

- If you put prefix in bgp redist rules, FW will create "dummy" route for this network and redistribute to BGP that network. Because this network is not associated with any interface, not it is static route with path monitor, this route will always be active and redistributed to BGP. The main purpose for this function is to redistribute range that you don't have in your routing table - for example additional NAT range that is used for NAT rules.

- If you want FW to stop redistributing prefix once the route is inactive you need to use redistribution profile. Redis profile will match the routes that are already in your routing table and add it to the BGP process.

You should be able to confirm the use "dummy route" by checking your routingtable. You should have route with flag "~"

Re: Path monitored static route not removed from BGP RIB out table when path monitor dest. IP unreachable.

kanes39 — Wed, 14 Jul 2021 13:15:10 GMT

Hi @aleksandar.astardzhiev,

I am using Redistribution Profile and not IP/Prefix on the BGP redistribution.

Unsure why even with a static route configured and redistribution profile created the route seems to be there at all times even after path monitoring fails. The only time the route goes away from the bgp redistribution is when the route statement is removed from the export list.

Regards,

Kanes.R

Re: Path monitored static route not removed from BGP RIB out table when path monitor dest. IP unreachable.

aleksandar.astardzhiev — Wed, 14 Jul 2021 15:09:18 GMT

Hi @kanes39,

If you filter your routing table for that prefix while the path monitor is down, what is the output?

Re: Path monitored static route not removed from BGP RIB out table when path monitor dest. IP unreachable.

kanes39 — Thu, 15 Jul 2021 01:05:38 GMT

@AlexanderAstardzhiev,

The route is still visible on the table.

Regards,

Kanes.R

Re: Path monitored static route not removed from BGP RIB out table when path monitor dest. IP unreachable.

Ben-Price — Mon, 26 Jul 2021 07:37:06 GMT

Hi @Astardzhiev, my issue turns out to be slightly different after doing some further troubleshooting, but I did lab up your scenario and you are correct the configuration you described, does result in the path monitored static route not being removed from the RIB out table.

Once I have a resolution for my issue, I will post here.

Thanks.