Solved: PAgP and lacp

sarahr202 · ‎05-27-2008

hi every body!

I need some help with following scenario:

suppose we have two switches,sw1 and sw2.

sw1 is connected to sw2 by f0/1,f0/2 and vice versa. Both ports are configured for trunking on sw1 and sw2.

I want to use etherchannel which will consist of f0/1,f0/2 on sw1 and sw2.

Below is the configuration pertaining to ether channel only:

sw1(config)# int f0/1

sw1(config-if)# channel-group pagp

sw1(config -if)# channel -group 1 mode desirable.

1)Do i need to configure explicitly "pagp" by using command " channel-group pagp" ?

case # 2 " using LACP"

In cisco bcmsn guide by david hucaby, I find following way to configure "LACP"

sw1(config)# int fo/1

sw1(config-if)# channel-protocol lacp

sw1 (config-if)# channel-group 1 mode active.

On cisco webside, i find the following way which does not use command " channel-group lacp"

sw1(config)int f0/1

sw (config-if) channel-group 1 mode active.

My question is if both methods are correct or one of them is correct then which one?

thanks alot!

glen.grant · ‎05-27-2008

No you do not have to specify it knows to use pagp when you put the commands on the inteface , channel-group 1 mode desirable non-silent . Channel-group 1 mode active specificlly applies to lacp only , no other config is needed to make it work.

View solution in original post

Edison Ortiz · ‎05-27-2008

Etherchanneling modes:

Active<->Active = LACP

Active<->Passive = LACP

Desirable<->Desirable = PAgP

Desirable<->Auto = PAgP

On<->On = On

The channel-protocol command ensures you are using the correct etherchannel mode. For instance, if you use channel-protocol lacp but incorrectly use the desirable<->desirable combination, the etherchannel will not form.

HTH,

__

Edison.