[c-nsp] LACP and QinQ

[David Wilkinson]

Hi,

We have a QinQ link and each end of the link goes to 2 ports setup in a 
LACP port channel. We have noticed that the traffic leaving the QinQ is 
only going out of one port and not balancing between the two ports.


I have tried changing the balancing algorithm used however doesn't seem 
to be making difference.

The Setup is as follows

End user device A -> <2x1G port channel> -> Cisco 4948 -> Rest of 
network -> Cisco 4948 -> <2x1G port channel> -> End user device B

The port channel facing the end user device are setup as a dot1Q tunnel

-------

interface GigabitEthernet1/1
  switchport access vlan 1337
  switchport mode dot1q-tunnel
  mtu 9198
  logging event link-status
  no cdp enable
  channel-protocol lacp
  channel-group 1 mode passive

interface GigabitEthernet1/2
  switchport access vlan 1337
  switchport mode dot1q-tunnel
  mtu 9198
  logging event link-status
  no cdp enable
  channel-protocol lacp
  channel-group 1 mode passive

interface Port-channel1
  switchport
  switchport access vlan 1337
  switchport mode dot1q-tunnel
  mtu 9198
  logging event link-status
  l2protocol-tunnel cdp
  l2protocol-tunnel stp
  l2protocol-tunnel vtp

#show etherchannel load-balance
EtherChannel Load-Balancing Configuration:
         src-dst-port

EtherChannel Load-Balancing Addresses Used Per-Protocol:
Non-IP: Source XOR Destination MAC address
   IPv4: Source XOR Destination TCP/UDP (layer-4) port number
   IPv6: Source XOR Destination IP address


#show etherchannel 1 detail
		Channel-group listing:
		----------------------

Group: 1
----------
Group state = L2
Ports: 2   Maxports = 8
Port-channels: 1 Max Port-channels = 1
Protocol:   LACP
		Ports in the group:
		-------------------
Port: Gi1/1
------------

Port state    = Up Mstr Assoc In-Bndl
Channel group = 1           Mode = Passive         Gcchange = -
Port-channel  = Po1         GC   =   -             Pseudo port-channel = 
Po1
Port index    = 0           Load = 0x00            Protocol =   LACP

Flags:  S - Device is sending Slow LACPDUs   F - Device is sending fast 
LACPDUs.
         A - Device is in active mode.        P - Device is in passive 
mode.

Local information:
                             LACP port     Admin     Oper    Port        
Port
Port      Flags   State     Priority      Key       Key     Number      
State
Gi1/1     SP      bndl      32768         0x40      0x40    0x1C        
0x3C

Partner's information:

Port     Flags State   Priority AdminKey DevID          Age  OperKey 
PortNum PortState
Gi1/1    FA    bndl    1        0x0      xxxx.xxxx.xxxx   1s 0x4E21  
0x10    0x3F

Age of the port in the current state: 5d:09h:57m:58s

Port: Gi1/2
------------

Port state    = Up Mstr Assoc In-Bndl
Channel group = 1           Mode = Passive         Gcchange = -
Port-channel  = Po1         GC   =   -             Pseudo port-channel = 
Po1
Port index    = 1           Load = 0x00            Protocol =   LACP

Flags:  S - Device is sending Slow LACPDUs   F - Device is sending fast 
LACPDUs.
         A - Device is in active mode.        P - Device is in passive 
mode.

Local information:
                             LACP port     Admin     Oper    Port        
Port
Port      Flags   State     Priority      Key       Key     Number      
State
Gi1/2     SP      bndl      32768         0x40      0x40    0x1D        
0x3C

Partner's information:

Port     Flags State   Priority AdminKey DevID          Age  OperKey 
PortNum PortState
Gi1/2    FA    bndl    1        0x0      xxxx.xxxx.xxxx  28s 0x4E21  
0x27    0x3F

Age of the port in the current state: 5d:09h:54m:52s

		Port-channels in the group:
		---------------------------

Port-channel: Po1    (Primary Aggregator)

------------

Age of the Port-channel   = 62d:23h:05m:40s
Logical slot/port   = 11/1           Number of ports = 2
Port state          = Port-channel Ag-Inuse
Protocol            =   LACP
Port security       = Disabled

Ports in the Port-channel:

Index   Load   Port     EC state        No of bits
------+------+------+------------------+-----------
   0     00     Gi1/1    Passive            0
   1     00     Gi1/2    Passive            0

Time since last port bundled:    5d:09h:54m:54s    Gi1/2
Time since last port Un-bundled: 5d:13h:43m:08s    Gi1/2


-------

It feels like it the switches are not looking at the right headers 
within the packet and not matching on the Layer 3/4 headers, possibly 
due to the packets being double tagged assuming it does the XOR before 
the outer tag is removed?
Any ideas on what might be going on here?


Regards

David