Symptom
Upon second PW configuration on existent BD (already including routed interface BVI and single PW) packet loss is observed and dropped packets are accounted against NP drop counter VPWS ingress DXID no match drop.
RP/0/RSP1/CPU0:ASR#show drops np np0 location 0/1/CPU0
Node: 0/1/CPU0:
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NP 0 Drops:
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VPWS ingress DXID no match drop 10106 <<<<<<<< HERE
Additionally, simplified BVI flag is observed incorrectly enabled for bridge domain which shouldn't be the case when there are 2 PWs in the bridge domain., which is causing the destination XID to be incorrectly read from the bridge domain structure rather than a MAC lookup.
RP/0/RSP1/CPU0:ASR#show uidb data location 0/1/CPU0 bvI 816 egress | inc BVI
UIDB_EXID_BVI_SIMPLIFIED 1 <<<<<<<< HERE
Using Ping/ICMP with destination of routed interface BVI will show that ICMP reply is dropped and all dropped packets accounted against VPWS ingress DXID no match drop.
Conditions
1. The linecard having the issue is lightspeed (LSQ or LSP).
2. The original BD has and only has 1 PW and 1 BVI in it.
3. Adding any additional bport such as AC or PW to the BD will move the BD to the bad state.
Workaround
Delete and re-configure bridge-domain routed interface BVI.
