Fast-reroute for egress link protection (ELP) feature is not working when spanning tree (STP) is also enabled on the interface. The presence of spanning tree is causing local MAC addressed to be flushed despite having ELP feature enabled.

Related configuration:

jnpr@switch> show configuration forwarding-options evpn-vxlan reroute-address | display set

set forwarding-options evpn-vxlan reroute-address inet 192.168.10.2

jnpr@switch> show configuration interfaces lo0.0 | display set

set interfaces lo0 unit 0 family inet address 192.168.10.1/32 primary

set interfaces lo0 unit 0 family inet address 192.168.10.1/32 preferred

set interfaces lo0 unit 0 family inet address 192.168.10.2/32

jnpr@switch> show configuration protocols rstp | display set

set protocols rstp bridge-priority 0

set protocols rstp interface ae1 edge

set protocols rstp bpdu-block-on-edge

If ae1 interface goes down on this leaf, the MAC addresses that were reachable through it will be removed and learned remotely:

-- leaf3's ethernet-switching table after link was disabled on host side (link towards leaf3)

{master:0}

labroot@jtac-qfx5120-32c-r2017-leaf3> show ethernet-switching table | match 00:21

vn2000 00:21:01:00:00:01 DR ae1.0      <<<<<<<<<   DR flag is unexpected in this case, it should be DLR

vn2001 00:21:01:00:00:02 DR ae1.0      <<<<<<<<<   DR flag is unexpected in this case, it should be DLR

... Omitted for brevity

This issue is fixed through PR1815823. 

2024-09-02 : Article Created

2024-10-24 : Added public PR link