Etherchannel Channel group numbers

[fantoos]

I have a 3750 as core switch, adding 2 stacks of 2960S to connect. I want to establish etherchannel between the 3750 and each additonal 2960S stack, do the channel group numbers between the 3750 and the new 2960s have to match? Please keep in mind 3750 has two channel-groups(1 and 2) already configured.

Need to know,  I would create 2 addtional channel groups (number 3,4) for each of the etherchannels between the 3 2960S Stacks and 3750? OR channel-group # is local to the device. Please review the attached config and advise if it is ok.

[Reza Sharifi]

Yes, you should match your channel group number on both sides of the connection..  Your config look good. You are using channel group 3 and 4 between the stacks and the 3750.  Usually between switch you run LACP or PAGP.

HTH

[johnnylingo]

Reza Sharifi wrote:
Usually between switch you run LACP or PAGP.

This is good advice - use PAgP or LACP when connecting Network Infrastructure devices.  If there's ever a problem with a channel member, both sides will take it out of the bundle and you won't have an outage.  

Port Channel should only be used on hosts that do not support LACP.

[tadeseg]

Reza 

The EtherChannel group number  is locally significant and No need of making the same 

[Leo Laohoo]

do the channel group numbers between the 3750 and the new 2960s have to match?

No.  The Etherchannel group numbers are locally significant to the appliance and they do not need to match.

[johnnylingo]

Both replies are correct. Group members do not have to match, however it's easier to keep track of what channel goes to which switch if they do.

One thing to watch out for is the 2960s may have a lower limit channel numbers, but with only a few stacks you'll be fine. 

[fantoos]

Really appreciate for all the replies,

Johnny, I'll go with the channel-group  3 and 4 config for the tracking purpose.

Thanks.