EtherChannel - live setup / migration

[Peter Nemec]

Hello, I am setting up an EtherChannel between CISCO 2960 and a 6500, both run IOS. Number of intended switchports in a bundle is 2. Is there any way I can do this without affecting the live network. There already is an uplink between the two, but is is getting close to 700Mbis/s and increasing, so I want to turn it into an EtherChannel to avoind any future bottleneck...

Peter

[Somasundaram Jayaraman]

Hi,

It is not possible to configure an etherchannel without shutting down the ports.

Ideally the configurations would be,

1. create a port-channel

2.configure the interfaces a part of port-channel.

Once the interfaces are mapped to the port-channel group, the interfaces will be in down state.

Once the port-channel is up, then only the interfaces gets bundled and forms a port-channel.

Hope this answers your question.

Cheers

Somu

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[Peter Nemec]

Hello,

thanks for your quick reply.

Do you mean that once I add the switchports into the port-channel group using (channel-group 1 mode desirable). Than I have to go into

(config)#interface port-channel 1

and type "no shut"

??

What if I create an "interface port-channel 1" first, and do "no shut" and that add the physical interfaces into the port-channel group ??

[Somasundaram Jayaraman]

Hi,

Please find my answers inline

What if I create an "interface port-channel 1" first, and do "no shut"  and that add the physical interfaces into the port-channel group ?? --  i havent tried yet.

But i think this will work, but still you definetly require down time for this. Because during bundling, the interfaces will go down and then comes up.

Do  you mean that once I add the switchports into the port-channel group  using (channel-group 1 mode desirable). Than I have to go into

(config)#interface port-channel 1

and type "no shut" --- This has worked for me in most cases.

Hope this helps..

Cheers

Somu

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[Peter Nemec]

OK thank you very much for clarifying that. Yes you are right about the downtime once an interface in being bundled into the channel group. I will have a thought and see if I can have a slight downtime.

How long you think the convergence might be ?

[smogra]

Convergence, means ports bouncing and bundling back to port channel, takes maximun 5-10 seconds.

Sweta

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[manju.cisco · Accepted solution]

Hi Peter,

I just tried, sometimes i get downtime of upto 30seconds.

As you already have the physical interfcae up and running,

Let's say you have port 1 and port 2 planned to put into etherchannel bundle.

The good one can be first to create port channel ex: Po1

1. Assign the port 2 to the etherchall with command "channel-group"

2. Configure all related commands to the portchannel(the same configs on portchannel will get applied to the port 2 also)

3. By the time you configure the the port channel the port 2 will bounce and comes back to function.

4. Do the same on the other end of the switch

NOTE HERE that, i have not bundled the current running port 1 to the portchannel bundle yet..i have kept it to keep running as it is......

5. Now, once you have the etherchannel up and running on both ends, do a shutdown on port 1 on both switches, so that the traffic now goes through the etherchannel over port 2.(probably you may get less seconds hit)

6. Then once you see traffic flows on the etherchannel, you can configure port 1 on both switches to join the etherchannel. and then you can configure load balancing on the port channel if you wish to.

I hope that would be working out with less live hit.....

More easy way would be to take a downtime of a minute and apply the configs

[Somasundaram Jayaraman]

Hi,

If the configurations are identical on both ends, mostly we will make errors in the speed and duplex part. So please configure it same on both the ends.

If we all set, then hardly it will take 15-30 seconds depending upon the etherchannel protocol you are running.

But i would suggest you to take downtime of 30 minutes, So that once the etherchannel comes up, we will have some more time for verification or any changes if we want to do after that.

Hope this helps

Cheers

Somu

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[Peter Nemec]

Hello guys,

thank you all for your help and the information provided. I will ask my manager whether I can proceed with setting it up the way you suggested and post all outcomes...

Cheers for now, you better be right...

Yes I will make sure that speed and duplex are the same at both end.

Also as manju.cisco suggested I tried setting up the "disabled" link, just for testing, and added the disabled port into channel-grou1 one and that has created port-channel interface 1 and if I add configuration on the port-channel 1 interface, the change reflects of the real psysical interface as well. It's really cool, cheers again.