ipspace
[BUG] SR Linux not setting next-hop-self on BGP RR
It looks like a SR Linux device running as a BGP route reflector does not do "next-hop-self".
Validation log @ https://netlab-cicd.pages.dev/srlinux/clab/bgp/03-ibgp-rr.yml-validate.log (the validation plugin threw an error, but based on the JSON dump, it's evident the next hop is not the loopback address of the route reflector)
Topology @ https://github.com/ipspace/netlab/blob/dev/tests/integration/bgp/03-ibgp-rr.yml
I solved a similar issue with a route map on Arista EOS. If that's not an option, we could add a device quirk to prevent this scenario.
Third party next hop support was recently added if I recall, that might fix it
(Edited your comment to remove the quoted email -- GitHub is doing a poor job these days)
I checked the SR Linux configuration for 02-ibgp-ebgp-session and 03-ibgp-rr. In the IBGP/EBGP case, you set "next-hop-self" to True, in the 03-ibgp-rr one you do not, which results in validation failure.
It could be that setting 'next-hop-self' affects reflected routes (like on Arista EOS), in which case you'd have to use a route map on IBGP updates, and I'm positive SR Linux had the ability to set BGP next hop to 'self' in a route map for a while (that's not a third-party next hop).
FWIW, the weird error in the validation log was caused by FRR validation plugin crashing when trying to report that the next hop is wrong. Fixed in 63047f07