Trunking over Lacp on 3560 switch

[andrewrocks]

I'm trying to run a trunk over a four port Lacp group to a netgear switch form a 3560 but am getting stuck. Everything works fine if I setup a trunk using a single standalone port, and everything works when I use a Lacp group in 'switchport access' mode, but as soon as I enable 'switchport trunk' the status of each gi goes to 'suspended' and no traffic will flow.

Does anyone have any suggestions?

Thanks.

[Peter Paluch]

Hello Andrew,

If you change the mode of the Etherchannel bundle from access to trunk, make sure that the switchport trunk encapsulation and switchport mode trunk commands are added both to the Port-channel interface and to the physical interfaces grouped under this EtherChannel. Ports moving into suspended state usually indicate that their physical configuration is different from the configuration on the Port-channel interface.

Best regards,

Peter

[andrewrocks]

Hi Peter,

I have set all those settings on the gi interfaces already, do I understand you correctly that I also need to do this on the po1 interface?

Thanks for your help on this.

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[Peter Paluch]

Hello Andrew,

I have set all those settings on the gi interfaces already, do I  understand you correctly that I also need to do this on the po1  interface?

Yes, absolutely. The settings are copied from physical interfaces to the Port-channel interface only when initially creating it, not afterwards.

As a matter of rule, all these changes should be configured on the Port-channel interface, as (almost) all configuration changes on the Port-channel interface will be propagated automatically down to the member ports. However, the opposite is not true.

Give it a try

Best regards,

Peter

[andrewrocks]

Excellent, I will try that tomorrow when I get to the office and report back.

Thanks again.

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[andrewrocks]

Hello,

I'm seeing some strange behaviour on this. The connection is working (i.e. I can ping the vlan ip from the net gear switch) for about 200 pings, but then I get no response for about 50 pings and then the pattern repeats.

Do you have any suggestions?

Thanks for your help.

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[Peter Paluch]

Andrew,

Would you mind posting your current Etherchannel configuration (i.e. the configuration of the Port-channel interface and of all the constituent physical ports) including the output of the show etherchannel and show etherchannel summary?

Best regards,

Peter

[andrewrocks]

Hi Peter,

My current running config is

http://pastebin.com/q664MAQk

here

And I'm also not getting any connection on the Native VLAN of the trunked connection.

Thank you again for your time.

Andrew.    

[Peter Paluch · Accepted solution]

Andrew,

Thank you for the additional information. The configuration of the ports seems to be okay now.

According to the show etherchannel output, the physical ports are in I-Individual state. That would mean that the switches have not negotiated the Etherchannel creation using the LACP, and the ports are still working as individual four switchports.

Does the neighboring switch speak LACP? Is it put into LACP Active mode? At least one device must be in LACP Active state, and both must speak LACP. Perhaps you could try replacing the commands channel-group 1 mode passive with channel-group 1 mode active in your configuration.

Best regards,

Peter

[andrewrocks]

Hi Peter,

After implementing your recommendations the switch  became more stable, but still not good enough. I have now tried with a  different model of netgear and it works fine with that switch using your  settings.

I'm going to assume that the switch is defective in some way and not use it.

Thank you for helping me track the issue.

Regards

Andrew.

[Peter Paluch]

Hello Andrew,

I am glad to have helped. While I am not entirely sure that your first Netgear switch is defective, it would probably take much more time to find out what is wrong with its settings which is not that important right now.

You are welcome any time.

Best regards,

Peter