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Cisco Bug: CSCvi06446 - incorrect default "switchport trunk native vlan tag" settings on trunk ports

Last Modified

Sep 19, 2019

Products (1)

  • Cisco Catalyst 6000 Series Switches

Known Affected Releases

15.2(1.3)

Description (partial)

Symptom:
Switch shows default "no switchport trunk native vlan tag" settings on trunk ports where in-fact "switchport trunk native vlan tag" is configured.

Example:
VSS#show run interface ten 1/5/4
Building configuration...

Current configuration : 142 bytes
!
interface TenGigabitEthernet1/5/4
 switchport
 switchport trunk native vlan 2
 switchport mode trunk
end

VSS#show running-config all | b interface TenGigabitEthernet1/5/4
interface TenGigabitEthernet1/5/4
 mvrp timer leave-all 1000
 mvrp timer leave 60
 mvrp timer join 20
 no mvrp timer periodic
 no mvrp
 switchport
 switchport trunk native vlan 2
 no switchport trunk native vlan tag <<<<<---- 
 switchport mode trunk
 mtu 1500
...

VSS#show vlan dot1q tag native 
dot1q native vlan tagging is enabled globally

Per Port Native Vlan Tagging State:
--------------------------------------------------

Port         Operational           Native VLAN
                Mode               Tagging State
--------------------------------------------------

Te1/5/4      trunk                  enabled   <<--- native tagging is enabled


In this configuration trunk ports with configured native vlan will not accept untagged traffic

Conditions:
Cat 6k running 15.2(1)SY3 + trunk port with native vlan
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