03-28-2011 01:37 AM - edited 03-06-2019 04:17 PM
Hi!
There is (again) something completely new for me.
A configured Layer 2 Port Channel (channel-group 40) with 2 Ports (Ten2/4, Ten5/4) in it on a 6500 with Sup720.
The strange thing is now there is a Port Channel 40 and also a Port Channel 40A each with 1 Port in it.
The only difference I recognised in the configuration is that "no cdp enable" is configured on one of the channel member ports.
Could this cdp configuration be the cause (cannot test at the moment, since this is critical production environment) for creating a "A" Port Channel?
I expected, that the channel is not built if port members are not configured equal, so I estimate another cause for this unusual situation...
Anyone has an explaination for this?
thanks for any hints!
br.herwig
Group: 40
----------
Group state = L2
Ports: 2 Maxports = 16
Port-channels: 2 Max Port-channels = 16
Protocol: LACP
Minimum Links: 0
Group Port-channel Protocol Ports
------+-------------+-----------+-----------------------------------------------
40 Po40(SU) LACP Te2/4(P)
40 Po40A(SU) LACP Te5/4(P)
interface Port-channel40
description Layer2_Portchannel
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
switchport nonegotiate
load-interval 30
interface TenGigabitEthernet2/4
description Layer2-Portchannel_
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
switchport nonegotiate
carrier-delay msec 0
udld port aggressive
no cdp enable
channel-group 40 mode active
interface TenGigabitEthernet5/4
description Layer2-Portchannel
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
switchport nonegotiate
carrier-delay msec 0
udld port aggressive
channel-group 40 mode active
router#show etherchannel 40 det
Group state = L2
Ports: 2 Maxports = 16
Port-channels: 2 Max Port-channels = 16
Protocol: LACP
Minimum Links: 0
Ports in the group:
-------------------
Port: Te2/4
------------
Port state = Up Mstr In-Bndl
Channel group = 40 Mode = Active Gcchange = -
Port-channel = Po40 GC = - Pseudo port-channel = Po40
Port index = 0 Load = 0xFF 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
Te2/4 SA bndl 32768 0x28 0x28 0x205 0x3D
Partner's information:
Partner Partner LACP Partner Partner Partner Partner Partner
Port Flags State Port Priority Admin Key Oper Key Port Number Port State
Te2/4 SA bndl 32768 0x0 0x28 0x205 0x3D
Age of the port in the current state: 3d:21h:55m:11s
Port: Te5/4
------------
Port state = Up Mstr In-Bndl
Channel group = 40 Mode = Active Gcchange = -
Port-channel = Po40A GC = - Pseudo port-channel = Po40
Port index = 0 Load = 0xFF 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
Te5/4 SA bndl 32768 0x28 0x28 0x505 0x3D
Partner's information:
Partner Partner LACP Partner Partner Partner Partner Partner
Port Flags State Port Priority Admin Key Oper Key Port Number Port State
Te5/4 SA bndl 32768 0x0 0x1028 0x505 0x3D
Age of the port in the current state: 3d:21h:55m:11s
Port-channels in the group:
----------------------
Port-channel: Po40 (Primary Aggregator)
------------
Age of the Port-channel = 346d:06h:32m:02s
Logical slot/port = 14/8 Number of ports = 1
HotStandBy port = null
Port state = Port-channel Ag-Inuse
Protocol = LACP
Fast-switchover = disabled
Load share deferral = disabled
Ports in the Port-channel:
Index Load Port EC state No of bits
------+------+------+------------------+-----------
0 FF Te2/4 Active 8
Time since last port bundled: 3d:21h:55m:11s Te2/4
Time since last port Un-bundled: 3d:21h:55m:17s Te5/4
Port-channel: Po40A
------------
Age of the Port-channel = 3d:21h:55m:18s
Logical slot/port = 14/6 Number of ports = 1
HotStandBy port = null
Port state = Port-channel Ag-Inuse
Protocol = LACP
Fast-switchover = disabled
Load share deferral = disabled
Ports in the Port-channel:
Index Load Port EC state No of bits
------+------+------+------------------+-----------
0 FF Te5/4 Active 8
Time since last port bundled: 3d:21h:55m:13s Te5/4
Last applied Hash Distribution Algorithm: Fixed
03-31-2011 03:48 PM
Hi Hgans,
See if this links helps you:
Usually its recommended to configure all the ports with the same configuration, sometimes it does allow you to form a port-channel but you will see such secondary port-channel formed.
Are linecards 2 and 5 same model linecards ?
JayaKrishna.
04-11-2011 05:35 AM
Hi,
hmm, interesting.
we have a second pair of 65k with similar channel setup under same IOS and hardware.
on these boxes I don't see this "sub" channels.
So at the moment I think the cause is indeed the "no cdp enable" configuration on one of the two member ports.
I will eliminate the cdp configuration in my next maintenance window and state a result here....
This are the Modules that form the channel:
2 8 CEF720 8 port 10GE with DFC WS-X6708-10GE
5 5 Supervisor Engine 720 10GE (Active) VS-S720-10G
Herwig
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