Conditional advertisement in eBGP based on ISIS status

[allalamine]

Hello networkers,

In MPLS L3VPN, can we advertise a route to eBGP neighbor only if there is at least one ISIS neighbor up ? (ISIS is the IGP and running in GRT). PE is an ASR 9010.

The neighbor is dual-homed and the advertised route from PE to neighbor is a default generated using default-generate.

Thank you

[MHM Cisco World]

https://blog.ipspace.net/2019/10/changing-cisco-ios-bgp-policies-based.html

check this link

[allalamine]

Thank you

To use this, I need to create as many IP SLA objects as ISIS neighbors. each IP SLA will ping a neighbor.

Gonna be hard to maintain as we should update config whenever we add/remove neighbors .. also convergence will be longer ..

[smilstea · Accepted solution]

This should get you started:

https://community.cisco.com/t5/service-providers-knowledge-base/conditional-route-advertisement/ta-p/3872594

Sam

[allalamine]

Thanks Sam

if rib-has-route would work with a prefix-list containing hosts like RR or NMS which are always up