[c-nsp] xconnect based pseudowire broken on one end

[Christian Kratzer]

Hi,

we are at our wits end with an mpls based pseudowire we are trying to setup between a 6504/Sup720 and a 6509/Sup2T.

Both switches are setup as Vss clusters.

We have a trunk port on both ends with vlan 21 being the specific vlan we want to pass over the xconnect.

Vlan 21 is specifically not in the vlan database because of the limitations of the sup720/pfc3 based platform without special wan line cards.

Mpls Layr3 vpns are working fine between the two boxes so we assume that our mpls setup is ok.

We have configured following (first two octets of the ips replaced to 192.168):

   6509-sup2t
   ----------

   interface Port-channel7
    switchport
    switchport trunk allowed vlan 21,40-49,100,3000-3499
    switchport mode trunk
   !
   interface Port-channel7.21
    encapsulation dot1Q 21
    xconnect 192.168.80.6 21 encapsulation mpls
   !

   6504-sup720
   -----------
   interface GigabitEthernet2/2/6
    switchport
    switchport trunk encapsulation dot1q
    switchport trunk allowed vlan 21,50,2000,2040,2041
    switchport mode trunk
    spanning-tree portfast edge trunk
   !
   interface GigabitEthernet2/2/6.21
    encapsulation dot1Q 21
    xconnect 192.168.80.5 21 encapsulation mpls
   !

We do see the xconnect coming up on both sides:

   6509-sup2t#show xconnect all
   Legend:    XC ST=Xconnect State  S1=Segment1 State  S2=Segment2 State
     UP=Up       DN=Down            AD=Admin Down      IA=Inactive
     SB=Standby  RV=Recovering      NH=No Hardware

   XC ST  Segment 1                         S1 Segment 2                         S2
   ------+---------------------------------+--+---------------------------------+--
   UP     ac   Po7.21:21(Eth VLAN)          UP mpls 192.168.80.6:21                UP



   6504-sup720#show xconnect all
   Legend:    XC ST=Xconnect State  S1=Segment1 State  S2=Segment2 State
     UP=Up       DN=Down            AD=Admin Down      IA=Inactive
     SB=Standby  HS=Hot Standby     RV=Recovering      NH=No Hardware

   XC ST  Segment 1                         S1 Segment 2                         S2
   ------+---------------------------------+--+---------------------------------+--
   UP     ac   Gi2/2/6.21:21(Eth VLAN)      UP mpls 192.168.80.5:21                UP

Looking at "show mpls l2transport vc 21 detail" we see packets going in and out on the sup720 but no received packets on the sup2t side.

We are also missing the "LDP is UP" part on the sup2t but we are puzzled as to why the xconnect might come up.

   6509-sup2t#show mpls l2transport vc 21 detail
   Local interface: Po7.21 up, line protocol up, Eth VLAN 21 up
     Interworking type is Ethernet
     Destination address: 192.168.80.6, VC ID: 21, VC status: up
       Output interface: Vl50, imposed label stack {44}
       Preferred path: not configured
       Default path: active
       Next hop: 192.168.81.6
     Create time: 1d02h, last status change time: 1d02h
     Signaling protocol: LDP, peer 192.168.80.6:0 up
>     Targeted Hello: 192.168.80.5(LDP Id) -> 192.168.80.6
       Status TLV support (local/remote)   : enabled/not supported
 	Label/status state machine        : established, LruRru
 	Last local dataplane   status rcvd: no fault
 	Last local SSS circuit status rcvd: no fault
 	Last local SSS circuit status sent: no fault
 	Last local  LDP TLV    status sent: no fault
 	Last remote LDP TLV    status rcvd: not sent
       MPLS VC labels: local 49, remote 44
       Group ID: local 0, remote 0
       MTU: local 1500, remote 1500
       Remote interface description: Vpls zu cr01
     Sequencing: receive disabled, send disabled
     VC statistics:
>     packet totals: receive 0, send 145832
>     byte totals:   receive 0, send 10532878
>     packet drops:  receive 0, send 0


   6504-sup720#show mpls l2transport vc 21 detail
   Local interface: Gi2/2/6.21 up, line protocol up, Eth VLAN 21 up
     Interworking type is Ethernet
     Destination address: 192.168.80.5, VC ID: 21, VC status: up
       Output interface: Vl50, imposed label stack {49}
       Preferred path: not configured
       Default path: active
       Next hop: 192.168.81.5
     Load Balance: none
     Flow Label: Disabled
     Create time: 1d02h, last status change time: 1d02h
     Signaling protocol: LDP, peer 192.168.80.5:0 up
>      Targeted Hello: 192.168.80.6(LDP Id) -> 192.168.80.5, LDP is UP
       Status TLV support (local/remote)   : enabled/not supported
 	LDP route watch                   : enabled
 	Label/status state machine        : established, LruRru
 	Last local dataplane   status rcvd: No fault
 	Last local SSS circuit status rcvd: No fault
 	Last local SSS circuit status sent: 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 44, remote 49
       Group ID: local 0, remote 0
       MTU: local 1500, remote 1500
       Remote interface description:
     Sequencing: receive disabled, send disabled
     Control Word: On (configured: autosense)
     VC statistics:
>     transit packet totals: receive 97473, send 90961
>     transit byte totals:   receive 7047328, send 6185360
>     transit packet drops:  receive 0, send 0


I am 50/50 split that this is an issue either in the mpls forwarding or something magic on the sup2t platform that we need to enable.

Also not sure if this might be related to using a port-channel on the sup2t side.

Any tips on what we might try next or what to look for in specific ?

Greetings
Christian Kratzer
CK Software GmbH

-- 
Christian Kratzer                      CK Software GmbH
Email:   ck at cksoft.de                  Wildberger Weg 24/2
Phone:   +49 7032 893 997 - 0          D-71126 Gaeufelden
Fax:     +49 7032 893 997 - 9          HRB 245288, Amtsgericht Stuttgart
Web:     http://www.cksoft.de/         Geschaeftsfuehrer: Christian Kratzer