suspended Interfaces status

Unanswered Question
Jul 1st, 2009

Hello ALL,

can anyone let me know what the reason that some interfaces show that are in suspended state when using the sh etherchannel summary command.



I have this problem too.
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Jerry Ye Wed, 07/01/2009 - 06:22

Hi Jean,

When a port in the etherchannel is in a suspended state means the port configuration is not compatible with others in the same etherchannel. Check you port configurations and make sure they are 100% match.



jeansamarani Wed, 07/01/2009 - 07:16

Hi Jerry,

thanks for your quick reply, i will check the ports configuration on each side? is there any link or reference on the cisco website that describe this issue?

N.B: the other side of the etherchannel is a Big IP loadbalancer.



glen.grant Wed, 07/01/2009 - 07:21

You would have to check and see if they are trying to etherchannel to the load balancer or not . Maybe its a leftover config thats not supposed to be there.

xcz504d1114 Wed, 07/01/2009 - 11:58

One more thing that can cause the etherchannel ports to go into a suspended state is when you are using two different types of link control, IE: One side is using LACP, the other side is using PaGP.

Check the log on the device with the suspended ports to verify. You might have to "shut" then "no shut" the suspended ports to generate a fresh log statement.



jeansamarani Thu, 07/02/2009 - 03:17

The other box is a Big IP loadbalancer. it's configured to use the LACP protocol and the same duplex and speed settings.

so you suggest to shut and no shut the suspended interfaces ?

xcz504d1114 Thu, 07/02/2009 - 06:15

Absolutely, that is the only way to clear the suspended state, once in a suspended state it is very much like being err-disabled, it doesn't try to automatically recover.

You will probably need to shut and no shut your port channel interface as well.

If they go back into a suspended state, do a show log and it will tell you why they went back into a suspended state. Typically if all of the ports in the etherchannel went into a suspended state it's because of a mismatched control protocol or a mismatch with the port-channel interface configuration.

On some devices the default behavior for a port-channel is a routed interface, so adding the "switchport" to the port-channel interface is sometimes required. Also, sometimes during the configuration of one side or the other it can trigger the suspended state, even though your final configuration is correct, you just need to shut no shut to clear the suspended state.

Make sure that if only part of the port-channel is down, you only shut no shut the suspended interfaces and don't shut no shut the port-channel interface, or else you will loose connectivity comnpletely.

Akhtar Samo Tue, 11/06/2012 - 13:04


Is there any way for the UP interface(P state) to detect the remote suspended interface state(S) and bring its interface down, suspend or un-bundle from Port Channel, so that the traffic doesn't get black holed on one link.

(S)-------------traffic black holed------------------(P)




wandering_997 Thu, 07/02/2009 - 18:24

My colleague told me F5 supports LACP and static link aggregation.

Suggest you use static mode to establish channel.

And why not show the configuration here?


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