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"
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?
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.
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.