CDP not working on trunk link between ASR920 IOS-XE and ASR 9006 IOS-XR interface

[michele.franchuk]

I work for a large service provider and we just started deploying ASR 920's as an edge solution for our customers,  here is the information along with the  configurations I have tried so far . 

cdp run is configured globally and cdp enabled is on the ASR 920 interface, facing our core 9006 router.  I am not able to get CDP to work from the ASR 920 to the ACR 9006.

I can see the ASR920 from the ACR9006 using cdp but not the other way around. The ASR920 shows output, but no input for the ACR9006 using the show command below.  The 9006 should not have the same issue as the 3400's using native VLAN 1, and I have tried the following commands on the service instances facing the 9006 on the 920's trunk port port.  Any suggestions or help to get this working, would be appreciated. 

l2protocol peer cdp

l2protocl forward cdp

ASR920#show cdp traffic
CDP counters :
Total packets output: 75, Input: 1
Hdr syntax: 0, Chksum error: 0, Encaps failed: 0
No memory: 0, Invalid packet: 0,
CDP version 1 advertisements output: 0, Input: 0
CDP version 2 advertisements output: 75, Input: 1

ASR 920 port facing ACR 9006 configuration:

interface TenGigabitEthernet0/0/5
mtu 9216
no ip address
load-interval 30
cdp enable

!Customer EPLN traffic
service instance <vlan> ethernet   
encapsulation dot1q <vlan>
rewrite ingress tag pop 1 symmetric
service-policy input QSP-CBS-10G-HFP-IN-MAP
service-policy output QSP-ALL-HFP-OUT-MAP
bridge-domain <vlan>
!

!

!L2 management for the 920 from a routed interface on the 9006
service instance <vlan> ethernet  
encapsulation dot1q <vlan>
rewrite ingress tag pop 1 symmetric
bridge-domain <vlan>
!

ACR 9006 port facing ACR 920 configuration:

RP/0/RSP0/CPU0:ASR9006#show run int te0/1/0/0*

Sat Jul 9 15:32:17.152 UTC
interface TenGigE0/1/0/0
cdp
mtu 9216
transceiver permit pid all
!

!Customer EPLN traffic
interface TenGigE0/1/0/0.<vlan> l2transport ---> customer EPLN traffic
encapsulation dot1q <vlan>
mtu 9212
!

!L2 management for the 920 from a routed interface on the 9006
interface TenGigE0/1/0/0.<vlan> l2transport  
encapsulation dot1q <vlan>
rewrite ingress tag pop 1 symmetric
!

[michele.franchuk]

I figured it out, I just needed a untagged service instance that was a part of bridge-domain 1 on the ASR920 facing the ACR9006 trunk port  along with my existing service instances that were already configured. Looks like it is the same solution as the 3400 native vlan 1 issue.   Happy Networking! 

---

---

interface TenGigabitEthernet0/0/5
mtu 9216
no ip address
load-interval 30
cdp enable

!

service instance 1 ethernet
encapsulation untagged
l2protocol peer cdp
bridge-domain 1
!

!Customer EPLN traffic
service instance <vlan> ethernet   
encapsulation dot1q <vlan>
rewrite ingress tag pop 1 symmetric
service-policy input QSP-CBS-10G-HFP-IN-MAP
service-policy output QSP-ALL-HFP-OUT-MAP
bridge-domain <vlan>

!

!L2 management for the 920 from a routed interface on the 9006
service instance <vlan> ethernet  
encapsulation dot1q <vlan>
rewrite ingress tag pop 1 symmetric
bridge-domain <vlan>
!

[chefwearer]

Good job! I had the same issue getting CDP to work between 920s and 7600s and 3400s, discussed here.