06-22-2022 05:26 AM
I have 3 routers 2 of which are running EBGP. These 2 are getting a default route which is being redistributed into OSPF. OSPF will then advertise this default route to the 3rd router. On RTR1 i am using default-information originate and on RTR2 i am using default-information originate metric 200. RTR3 is receiving the default route from RTR1 however when BGP on RTR1 loses its default route from BGP RTR3 still has the default route from RTR1. The only way i have found to make it use the default route from RTR2 is to shut the link to RTR1 and clear the OSPF process. I am not using the ALLWAYS on the default-information originate.
This is on a Cisco ASR-920-12CZ-A running Cisco IOS XE Software, Version 03.18.06.SP.156-2.SP6-ext
Any ideas.
06-22-2022 05:51 AM
Can you show use configuration information, how these connected any small network diagram to understand ?
are these Routers connected to external with different provider ?
06-22-2022 06:24 AM
The RTR 1 and 2 are connected to 2 different ISP's
06-23-2022 06:14 AM
Can you post the configuration of the routers?
06-22-2022 06:55 AM
friend since the RTR1 learn the default-information from OSPF (which get it from RTR2) then this loop is endless.
what you Need here ?
Try
bgp default-information route-map 0.0.0.0
route-map 0.0.0.0
match next-hop (ISP RTR1 connect to)
06-23-2022 01:37 AM
Hi,
the 0.0.0.0 is learnt from EBGP on rtr1 and 2. It is then redistributed into OSPF and advertised to rtr3
06-23-2022 04:53 AM
rtr1 and rtr2 is connect via OSPF ?
If yes then when rtr1 failed receive 0.0.0.0 from ISP it must not advertise it into OSPF BUT
rtr1 even it not receive the 0.0.0.0 from ISP it still receive it from OSPF, and hence the 0.0.0.0 still appear in rtr1 and rtr1 still advertise it into OSPF.
So how can I check this??
when rtr1 failed receive 0.0.0.0 from ISP check RIB what is the next-hop for 0.0.0.0 ? is it rtr2 or internal SW? if yes then you need conditional advertise 0.0.0.0 as I mention above.
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