Service Interruption between QINQ devices
Physical Network Topology
SwitchA sends ping packets carried vlan10 tag; on SwitchB, enable vlan-stacking and vlan-mapping on GE0/0/25, and the inner VLAN tag is 210 and outer WLAN tag is 2010; on switchC, dot1q-tunnel is enabled on GE2/0/25, which causes SwitchA and SwitchD can ping through each other.
Fault Description
switchA can not ping switchd.
Configuration Files
SwitchA:
#
interface Vlanif10
ip address 192.168.1.1 255.255.255.0
#
interface GigabitEthernet1/0/25
port link-type trunk
port trunk allow-pass vlan 10
#
SwitchB:
#
interface GigabitEthernet0/0/25
port link-type hybrid
qinq vlan-translation enable
undo port hybrid vlan 1
port hybrid tagged vlan 10
port hybrid untagged vlan 2010
port vlan-stacking vlan 210 stack-vlan 2010
port vlan-mapping vlan 10 map-vlan 210
#
interface GigabitEthernet0/0/26
port link-type trunk
port trunk allow-pass vlan 2010
#
SwitchC:
#
interface GigabitEthernet2/0/26
port link-type trunk
port trunk allow-pass vlan 2010
#
interface GigabitEthernet2/0/25
port link-type dot1q-tunnel
port default vlan 2010
#
SwitchD:
#
interface GigabitEthernet0/0/25
port link-type trunk
port trunk allow-pass vlan 210
#
interface Vlanif210
ip address 192.168.1.2 255.255.255.0
#
Troubleshooting Location
Step 1 Check whether to have learned the remote's ARP entry on switchA and switchD.
<switchA> display arp | in 192.168.1
IP ADDRESS MAC ADDRESS EXPIRE(M) TYPE INTERFACE VPN-INSTANCE
VLAN/CEVLAN
------------------------------------------------------------------------------
192.168.1.1 a08c-f8bb-803b I - Vlanif10
------------------------------------------------------------------------------
Total:36 Dynamic:29 Static:0 Interface:7
It shows that switchA have not learn the ARP of switchD.
<switchD> display arp | in 192.168.1
IP ADDRESS MAC ADDRESS EXPIRE(M) TYPE INTERFACE VPN-INSTANCE
VLAN/CEVLAN
------------------------------------------------------------------------------
192.168.1.2 a08c-f88d-1391 I - Vlanif210
------------------------------------------------------------------------------
Total:38 Dynamic:36 Static:0 Interface:2
It shows that switchD have not learn the ARP of switchA.
Step 2 After switchA and switchD ping each other, check the MAC address.
<SwitchA> display int Vlanif 10
Vlanif10 current state : UP
Line protocol current state : UP
Last line protocol up time : 2018-09-10 12:29
Description:
Route Port,The Maximum Transmit Unit is 1500
Internet Address is 192.168.1.1/24
IP Sending Frames' Format is PKTFMT_ETHNT_2, Hardware address is a08c-f8bb-803b
Current system time: 2018-09-10 12:29
Input bandwidth utilization : --
Output bandwidth utilization : --
<SwitchD> display interface Vlanif 210
Vlanif210 current state : UP
Line protocol current state : UP
Last line protocol up time : 2018-09-10 12:29
Description:
Route Port,The Maximum Transmit Unit is 1500
Internet Address is 192.168.1.2/24
IP Sending Frames' Format is PKTFMT_ETHNT_2, Hardware address is a08c-f88d-1391
Current system time: 2018-09-10 12:29
Input bandwidth utilization : --
Output bandwidth utilization : --
<SwitchA> display mac-address GigabitEthernet 1/0/25
-------------------------------------------------------------------------------
MAC Address VLAN/VSI Learned-From Type
-------------------------------------------------------------------------------
643e-8c30-9c40 1/- GE1/0/25 dynamic
c80c-c8dc-fec0 1/- GE1/0/25 dynamic
d4c8-b02e-8ec0 1/- GE1/0/25 dynamic
fce3-3c9f-3f70 10/- GE1/0/25 dynamic
-------------------------------------------------------------------------------
Total items displayed = 4
<SwitchB> display mac-address GigabitEthernet 0/0/25
-------------------------------------------------------------------------------
MAC Address VLAN/VSI/BD Learned-From Type
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
Total items displayed = 0
<SwitchB> display mac-address GigabitEthernet 0/0/26
-------------------------------------------------------------------------------
MAC Address VLAN/VSI/BD Learned-From Type
-------------------------------------------------------------------------------
643e-8c30-9c40 2010/-/- GE0/0/26 dynamic
a08c-f88d-1391 2010/-/- GE0/0/26 dynamic
c80c-c8dc-fec0 2010/-/- GE0/0/26 dynamic
d4c8-b02e-8ec0 2010/-/- GE0/0/26 dynamic
<SwitchC> display mac-address GigabitEthernet 2/0/26
-------------------------------------------------------------------------------
MAC Address VLAN/VSI Learned-From Type
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
Total items displayed = 0
<SwitchC> display mac-address GigabitEthernet 2/0/25
-------------------------------------------------------------------------------
MAC Address VLAN/VSI Learned-From Type
-------------------------------------------------------------------------------
643e-8c30-9c40 2010/- GE2/0/25 dynamic
a08c-f88d-1391 2010/- GE2/0/25 dynamic
c80c-c8dc-fec0 2010/- GE2/0/25 dynamic
d4c8-b02e-8ec0 2010/- GE2/0/25 dynamic
fce3-3c9f-3f70 2010/- GE2/0/25 dynamic
-------------------------------------------------------------------------------
Total items displayed = 5
<SwitchD> display mac-address GigabitEthernet 0/0/25
-------------------------------------------------------------------------------
MAC Address VLAN/VSI Learned-From Type
-------------------------------------------------------------------------------
fce3-3c9f-3f70 1/- GE0/0/25 dynamic
-------------------------------------------------------------------------------
Total items displayed = 1
From the above information, we can know:
After switchA pings switchD, GE0/0/25 on switchB did not learn MAC address of vlanif10 of switchA.
After switchD pings switchA, GE0/0/26 on switchB have learned the MAC address of vlanif210 of switchD.
It indicates that the ping packet was discarded in GE0/0/25 on switchB.
SwitchB can learn the MAC address of the switchA of vlanif, but the VLAN is 210; indicating that only vlan-mapping takes effect and vlan-stacking does not.
Step 3 Run the port vlan-stacking vlan 10 stack-vlan 2010 map-vlan 210 command, and the service is restored to normal.
[switchA-GigabitEthernet0/0/25] port vlan-stacking vlan 10 stack-vlan 2010 map-vlan 210
Root Cause
For fixed switches running V200R011C10SPC600 and later versions, the port vlan-stacking vlan 10 stack-vlan 2010 map-vlan 210 command is added to configure VLAN mapping and VLAN stacking together. For fixed switches running earlier versions, the VLAN mapping and VLAN stacking functions cannot be configured together.
When the port vlan-stacking vlan 210 stack-vlan 2010 and port vlan-mapping vlan 10 map-vlan 210 commands are run on an interface, only the VLAN mapping function takes effect.
