Etherchannel problems on cisco 6509

Zigmunds Vitins · ‎06-15-2011

Hi all,

I have Cisco 6509 with 5 ether-channel configured on it.

On one ether-channel other side are Dell Powerconnect 5448 switch.

All is working fine for some month, but today for some reasons this Po was disabled (already 4 times).

On Cisco in logs I can see:

48w2d: %PM-SP-4-ERR_DISABLE: channel-misconfig error detected on Po3, putting Gi3/5 in err-disable state

48w2d: %PM-SP-4-ERR_DISABLE: channel-misconfig error detected on Po3, putting Gi4/5 in err-disable state

48w2d: %PM-SP-4-ERR_DISABLE: channel-misconfig error detected on Po3, putting Po3 in err-disable state

On Dell are no entry about this problem.

Configuration on cisco are:

interface Port-channel3

description Po3

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 15-18,25,35,x,x,x,x

switchport mode trunk

no ip address

end

interface GigabitEthernet3/5 (also gi4/5)

description Po3

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 15-18,25,35,x,x,x,x

no ip address

no cdp enable

channel-group 3 mode on

end

On Dell Pc 5448 configuration are:

interface port-channel 1

description Po3

exit

interface port-channel 1

switchport mode trunk

exit

interface port-channel 1

switchport trunk allowed vlan add 15-18,25,35,x,x,x,x

exit

interface range ethernet g(45-48)

channel-group 1 mode on

exit

How can I found what is reason of this problem?

Thanks.

Zigmunds

lgijssel · ‎06-15-2011

Please verify the allowed vlan list is identical on both sides.

regards,

Leo

Antonio Knox · ‎06-15-2011

In addition to Leo's sggestion,

for 'interface Port-channel3'

no cdp enable

for 'interface GigabitEthernet3/5 (also gi4/5)'

switchport mode trunk

Zigmunds Vitins · ‎06-15-2011

Hi,

thanks.

About: "switchport mode trunk" in gi4/5 and 3/5 - there is this parameter, I accidentally deleted it when post

about cdp:

cisco(config)#int po3

cisco(config-if)#no cdp enable

% CDP already disabled since not supported on this interface, or for this encapsulation

ok, I will check all vlans

Zigmunds Vitins · ‎06-15-2011

Hi,

allowed vlan list on both sides ar equal.

what should I chech next?

Thanks.

Antonio Knox · ‎06-15-2011

Post output for

show etherchannel port-channel

show etherchannel port

show etherchannel summary

Though the Dell should default to standard 802.1q encapsulation, I would hard-code that on the 5448 side as well.

Zigmunds Vitins · ‎06-15-2011

Hi,

show etherchannel port-channel:

Ports in the Port-channel:

Index Load Port EC state No of bits

------+------+------+------------------+-----------

0 55 Gi3/5 On 4

1 AA Gi4/5 On 4

Time since last port bundled: 0d:01h:19m:15s Gi4/5

Time since last port Un-bundled: 0d:01h:20m:28s Gi4/5

show etherchannel port:

Group: 3

----------

Ports in the group:

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

Port: Gi3/5

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

Port state = Up Mstr In-Bndl

Channel group = 3 Mode = On Gcchange = -

Port-channel = Po3 GC = - Pseudo port-channel = Po3

Port index = 0 Load = 0x55 Protocol = -

Age of the port in the current state: 0d:01h:20m:22s

Port: Gi4/5

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

Port state = Up Mstr In-Bndl

Channel group = 3 Mode = On Gcchange = -

Port-channel = Po3 GC = - Pseudo port-channel = Po3

Port index = 1 Load = 0xAA Protocol = -

Age of the port in the current state: 0d:01h:20m:22s

cisco#show etherchannel summary

Flags: D - down P - bundled in port-channel

I - stand-alone s - suspended

H - Hot-standby (LACP only)

R - Layer3 S - Layer2

U - in use f - failed to allocate aggregator

M - not in use, minimum links not met

u - unsuitable for bundling

w - waiting to be aggregated

Number of channel-groups in use: 7

Number of aggregators: 7

Group Port-channel Protocol Ports

------+-------------+-----------+-----------------------------------------------

1 Po1(SU) - Gi3/7(P) Gi4/7(P)

2 Po2(SU) - Gi3/8(P) Gi4/8(P)

3 Po3(SU) - Gi3/5(P) Gi4/5(P)

4 Po4(SU) - Gi3/3(P) Gi4/3(P)

5 Po5(SU) - Gi3/6(P) Gi4/6(P)

11 Po11(SU) - Gi7/3(P) Gi8/3(P)

20 Po20(SU) - Gi3/15(P) Gi3/16(D) Gi4/15(P) Gi4/16(D)

On dell switch I found very little information about port-channel:

show interfaces port-channel 1

Load balancing: Layer 2.

Gathering information...

Channel Ports

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

ch1 Active: g(45-46) Inactive: g(47-48)

Thanks.

smogra · ‎06-15-2011

Hi,

1. Do a shut and no shut on the ports and see if they join back the etherchannel bundle.

2. Try changing the channel group mode to desirable mode and test again.

3. The errors comes this way. When you configure an etherchannel between two switches, you do it one at a time. As long as they are connected, at one moment one switch will have the config and the other will not - that is where the "misconfig" falls in. As soon as this is detected, the involved ports will be placed into err-disabled state. One way to configure an etherchannel if you do not want to disable the ports first could be to use the following command:

"no spanning-tree etherchannel guard misconfig" on switches. This is a global config command and is applied across the entire switch.

This way communication continues to happen - and switch will see any misconfigs as you carry out your configurations. The etherhcannel guard feature is on by default and it is the one that reports on this and err-disables the ports as soon as it notices a misconfiguration on the etherchannel.

It is a useful feature so after you finish configuring and your port-channel comes up - turn it back on as follows:

"spanning-tree etherchannel guard misconfig"

Hope this helps.

Sweta

Antonio Knox · ‎06-15-2011

Sweta has a good point.

glen.grant · ‎06-15-2011

I would make sure it matches on both sides. Looks like you have 2 ports configured in your port channel on the cisco side and 4 ports configured on the dell side . Maybe it doesn't like that . Might want to think about using LACP for your port channels instead of forcing the channel on . The dell should support that .

Leo Laohoo · ‎06-15-2011

1. Correct me if I'm wrong, but doesn't Dell switches support "LACP"?

2. How did you change the settings of your etherchannel on the 6500? The reason why I'm asking because in some cases (due to IOS), you can just edit a line out during configuration (like putting a "no" to remove the line). With the 6500 you have to remove the port channel completely (no interface Po ) and then putting it back in via the physical interface (channel-group mode on).

Zigmunds Vitins · ‎06-15-2011

Hi,

thanks all.

Sweta - I will try your suggestions.

Yesterday after 8th downtime ( it happens every 40 min) I remove port channel and leave singe port configuration on both sides

Now I will create new one Po config with test connections and test it.

Thanks.

ciscona728 · ‎06-16-2011

Leolaohoo has a point. Shouldn't you use LACP

So instead of the channel-group being set to on set it to active. Try the following:

channel-group {#} mode active

Thanks in advance