This topic how to produce the problem.
this the topology made with GNS3 lab.
CE advertise it’s loopback ip 192.168.0.100 to PE1 & PE2 with diffrent path length, hope that short bgp_path will be choosen as we can see in PE3
try this steps:
- After CE rebooted everything looks fine. from PE3 we can see 192.168.0.100 with shorted path has been selected.
- After that try to disable peer PE-1 from CE, then we can see from PE3 that 192.168.0.100 with longest path has been selected
3.Then try to enable again peer PE-1 from CE, then the problem happen, from PE3 we can still see 192.168.0.100 with longest path keep selected.
4.To make sure now you can disable peer PE-2 from CE, now from PE3 we can see 192.168.0.100 with shorted path has been selected.
5.Then try to enable peer PE-2 again from CE and from PE3 we can see 192.168.0.100 with shorted path still selected.
Problem happen exactly i explain at point 3 after prefix with longest path selected it wont come back to shorted path until we remove prefix with longest path from routing table.
I already try to replace PE with cisco or vyos problem point 3 did not happen. (see attachment for vyos configuration)
soon after peer PE-1 has been enabled, then we can see that prefix with shorted path selected.
i also found another problem, sometimes after disable peer from CE then enable it, sometime bgp stuck cannot established, until i have to enable/disable BGP on PE’s
hope everything clear maris, i already report this issues years.
please check and test this topology in yours labs.
thx
vyos-PE-1.txt (3.95 KB)
vyos-PE-2.txt (3.87 KB)
PE2-v7.rsc (3.27 KB)
PE3-v6.rsc (1.88 KB)
RR-1-v6.rsc (1.49 KB)
PE1-v7.rsc (3.43 KB)
PE2-v6.rsc (2.16 KB)
PE1-v6.rsc (2.23 KB)
CE-CUST01-v6.rsc (1.76 KB)