Hi Mahmood,

Yes, PAgP and LACP are protocols that serve only to negotiate the channel. It is recommended to enable them if possible as these protocols also provide inherent error detection capabilities.

The load balancing aspect of the etherchannel is built into the hardware, so once the channel index is programmed into the port ASIC, the load balancing algorithm automatically distributes the traffic among the ports, depending on the configured scheme (SRC and/or DST MAC and/or IP, etc.)

HTH,

Bobby

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Bobby,

I was thinking same as you said. I am thinking PAGP only for finding capable ports ,automatic negotiation and adding those ports in to etherchannel...other then this there is no role for pagp in etherchannel

Do you agree with me ? or i am misunderstood.

Regards,

Rajesh

Rajesh,

You are mostly correct. The other role for PAgP is to maintain the integrity of the channel. Should a problem occur on a link (such as a marginal port, etc.), PAgP would disable the channel, whereas with mode on, the channel stays up as long as the physical link is up. Cisco's recommended best practice is to use PAgP or LACP for channel negotiation.

HTH,

Bobby

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Mahmood,

U mean to say for load balancing it will use pagp..

Regards,

Rajesh

HI

No as bobby said that PAGP and LACP are used to find the channel capable ports i think it has nothing to do with load-balancing.as bobby said it all depends which method u use.ie based on source or destination mac or IP.

Thanks

Mahmood