QinQ over ASR 9910 not working

[vladdar1349]

Hello all,

I am trying to transport double tagged traffic over the Cisco ASR 9910 but with no luck. It works only with one tag and I don't know why. I am not able to ping through with double tags, not even ARP is learned. Traffic is with tags 679 (outer) and 100 (inner) coming to interface BE55.679 and should be forwarded to the interface GigabitEthernet0/3/0/1 only with tag 100 (also receiving traffic on this int is only with tag 100). It also didn't work when  I used double tagging on interface GigabitEthernet0/3/0/1.

Here is the configuration:

!

l2vpn

bridge group vlan679
bridge-domain vlan679
mtu 9000
interface Bundle-Ether55.679
!
interface GigabitEthernet0/3/0/1

!

interface Bundle-Ether55
mtu 9212
bundle minimum-active links 1

!

interface Bundle-Ether55.679 l2transport
description test-vlan679outer-vlan100inner
encapsulation dot1q 679
rewrite ingress tag pop 1 symmetric

!

interface GigabitEthernet0/3/0/1
description test-vlan100
mtu 9212
transceiver permit pid all
l2transport

!

!

#sh l2vpn forwarding bridge-domain vlan679:vlan679 mac-address location 0/3/CPU0
Tue May 15 09:42:18.964 utc
To Resynchronize MAC table from the Network Processors, use the command...
l2vpn resynchronize forwarding mac-address-table location <r/s/i>

Mac Address Type Learned from/Filtered on LC learned Resync Age/Last Change Mapped to
-------------- ------- --------------------------- ---------- ---------------------- --------------
6c3b.6bb4.7f3f dynamic Gi0/3/0/1 0/3/CPU0 15 May 09:39:19 N/A
4c5e.0cfd.c047 dynamic BE55.679 0/3/CPU0 15 May 09:39:49 N/A

sh platform:

0/RSP0/CPU0 A99-RSP-TR(Active) IOS XR RUN PWR,NSHUT,MON
0/RSP1/CPU0 A99-RSP-TR(Standby) IOS XR RUN PWR,NSHUT,MON
0/0/CPU0 A9K-MOD160-TR IOS XR RUN PWR,NSHUT,MON
0/0/0 A9K-MPA-8X10GE OK PWR,NSHUT,MON
0/0/1 A9K-MPA-2X40GE OK PWR,NSHUT,MON
0/1/CPU0 A9K-4T16GE-TR IOS XR RUN PWR,NSHUT,MON
0/3/CPU0 A9K-40GE-TR IOS XR RUN PWR,NSHUT,MON
0/4/CPU0 A9K-40GE-TR IOS XR RUN PWR,NSHUT,MON
0/6/CPU0 A9K-4T16GE-TR IOS XR RUN PWR,NSHUT,MON
0/7/CPU0 A9K-MOD160-TR IOS XR RUN PWR,NSHUT,MON
0/7/0 A9K-MPA-8X10GE OK PWR,NSHUT,MON
0/7/1 A9K-MPA-2X40GE OK PWR,NSHUT,MON

Version is 6.0.2

Any help would be much appreciated.

Thank You.

[xr-escalation]

you are popping only a single tag on frames with QinQ. Try popping both.

[vladdar1349]

Tried that:

!

interface Bundle-Ether55.679 l2transport
description test
encapsulation dot1q 679 second-dot1q 100
rewrite ingress tag pop 2 symmetric

!

untagged traffic on GigabitEthernet0/3/0/1 but no change. Still doesn't work.

[xr-escalation]

hmm, this should work...

Can you share

sh l2vpn bridge-domain bd-name
sh l2vpn forwarding platform bridge-domain mac-address location

/Aleksandar

[vladdar1349 · Accepted solution]

Hello all,

I found the that the issue lies elsewhere on the path. One of the switches along the path does not support QinQ, looks like it strips the inner tag. I didn't think of it, as I never encountered a switch which would not be able to transport QinQ when it has sufficient MTU. I thought that switch only looks at the first (outer) tag and doesn't care what is after it.

So all is OK on ASR.

Thank you all for replies.