EoMPLS vlan rewrite between brands; possibly new bug in Cisco IOS 15

Jeff Tantsura jeff.tantsura at ericsson.com
Sun Nov 15 01:54:51 UTC 2015


As expected - the problem is related to vc type negotiation.

You have hit CSCuq28998 :)
talk to your cisco rep	

- configure VC type 5 between the routers (configured on HP side)
- configuring no-control-word 

The bug has been reported in 15.2(4)S4a, perhaps there’s an image with the problem fixed.


On 11/14/15, 17:31, "Jonas Bjork" <mr.jonas.bjork at me.com> wrote:

>Dear Mr. Jeff,
>Thank you for your reply. Below is the complete output in question (l2 is short for l2transport).
>You are mentioning platform capabilities and that the default might have changed. How do I alter this?
>pe#sh mpls l2 vc 42 d
>Local interface: Po190.42 up, line protocol up, Eth VLAN 42 up
>  Destination address: X.X.1.89, VC ID: 42, VC status: down
>    Last error: Imposition VLAN rewrite capability mismatch with peer
>    Output interface: none, imposed label stack {}
>    Preferred path: not configured
>    Default path: no route
>    No adjacency
>  Create time: 00:00:59, last status change time: 00:31:40
>    Last label FSM state change time: 00:00:18
>    Last peer autosense occurred at: 00:00:18
>  Signaling protocol: LDP, peer X.X.1.89:0 up
>    Targeted Hello: X.X.0.2(LDP Id) -> X.X.1.89, LDP is UP
>    Graceful restart: not configured and not enabled
>    Non stop routing: not configured and not enabled
>    Status TLV support (local/remote)   : enabled/not supported
>      LDP route watch                   : enabled
>      Label/status state machine        : remote invalid, LruRnd
>      Last local dataplane   status rcvd: No fault
>      Last BFD dataplane     status rcvd: Not sent
>      Last BFD peer monitor  status rcvd: No fault
>      Last local AC  circuit status rcvd: No fault
>      Last local AC  circuit status sent: DOWN PW(rx/tx faults)
>      Last local PW i/f circ status rcvd: No fault
>      Last local LDP TLV     status sent: No fault
>      Last remote LDP TLV    status rcvd: Not sent
>      Last remote LDP ADJ    status rcvd: No fault
>    MPLS VC labels: local 242, remote 1199
>    Group ID: local 0, remote 0
>    MTU: local 9216, remote 9216
>    Remote interface description:
>    Remote VLAN id: 42
>  Sequencing: receive disabled, send disabled
>  Control Word: Off (configured: autosense)
>  SSO Descriptor: X.X.1.89/42, local label: 242
>  Dataplane:
>    SSM segment/switch IDs: 0/0 (used), PWID: 142
>  VC statistics:
>    transit packet totals: receive 0, send 0
>    transit byte totals:   receive 0, send 0
>    transit packet drops:  receive 0, seq error 0, send 0
>Anyone else: feel free to join in. Maybe we have any L2VC/PW ninjas watching.
>Best regards,
>Jonas Bjork
>> On 15 Nov 2015, at 1:26, Jeff Tantsura <jeff.tantsura at ericsson.com> wrote:
>> Been forever since i looked at cisco, however sounds like vc type mismatch. They used to have it as a platform capability, perhaps SW upgrade changed the default.
>> to my memory "show mpls l2 transport" should provide enough details.
>> Hope this helps
>> Regards,
>> Jeff
>>> On Nov 14, 2015, at 4:50 AM, Jonas Bjork <mr.jonas.bjork at me.com> wrote:
>>> Hi, I am using a couple of AToM/EoMPLS tunnels in order to carry customer voice and data traffic across our IP/MPLS core, and it is currently working just fine. The first side consists of a Cisco 7600 router (rsp) and the other one is an HP A5500-HI routing switch with full LER/E-LSR capability. At the HP site, the tunnels are facing the access ports towards our premium end-customers; and on the Cisco PE I terminate the tunnels on one of the 2x10GE portchannel backbone links. There is vlan X on the HP side and vlan Y on the Cisco side - vlan rewrite is working perfectly - as long as I use IOS 12.
>>> After upgrading the Cisco router software to IOS 15 the tunnels won't come up. sh mpls l2 vc Y d says:
>>> ...
>>> Last error: Imposition VLAN rewrite capability mismatch with peer
>>> ...
>>> I use almost exactly the same Cisco configuration before and after the upgrade (only minor changes and nothing related to this) and I havn't touched the HP. Apparently they don't talk the same L2PW language. I wonder though, why now? We use service instances on the HP switchport as endpoint, we initiate the targetted LDP session in addition to the pseudowire handshake from a sub interface MPLS crossconnect. There is no MTU mismatch; not here - not anywhere.
>>> Anyone heard of this issue or experienced it?
>>> Best regards,
>>> Jonas Björk
>>> SNE, Europe/Sweden (hope you guys will help me anyway:)

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