Description

Packet drops are observed for traffic transiting switch in a QinQ network.  Using cli command 'show ethernet-switching table <>' where <> is the SMAC of affected flow identified the cause of traffic blackholing as MAC move. To resolve this issue filter the traffic in order to prevent mac moving. 

 

Symptoms

Traffic drops were resulting due to MAC moves in the QinQ network. To check that a MAC address has moved:

{master:0}
root@switch> show ethernet-switching table aa:aa:aa:aa:aa:aa
Ethernet switching table: 1 entry, 1 learned
Routing instance: default-switch
Vlan     MAC                        MAC    Age     Logical        NH      RTR
name   address                   flags              interface      Index  ID
S2       aa:aa:aa:aa:aa:aa      D        -       xe-0/0/0.2   0        0   >>>>>> Mac learned

 

{master:0}
lab> show ethernet-switching table aa:aa:aa:aa:aa:aa
Ethernet switching table: 1 entry, 1 learned
Routing instance: default-switch
Vlan     MAC                       MAC   Age      Logical        NH      RTR
name   address                  flags              interface      Index  ID
S2       aa:aa:aa:aa:aa:aa     D       -        xe-0/0/1.2   0        0 >>>>>> Mac moved

 

Solution

To resolve this issue filter the traffic in order to prevent mac moving. 

 

Modification History

2024-09-13 : KB Updated
2024-06-27 : Article Created