Etherchannel 3750 questions

ValerioVale · ‎11-20-2007

Hello,

I would like to deploy this kind of configuration (See attached network plan).

My questions are:

1) is possible to enable etherchannel links between different switches, without stacking links?

2) how is the expected bandwith consumption when I enable etherchannel PAgP or LACP protocol?

Thanks a lot,

Kevin Dorrell · ‎11-20-2007

Yes, you can run the links between the switches as EtherChannels. This is a particularly useful technique if you want the switches to be located further than a stacking link will allow.

As for PAgP and LACP, the bandwidth they use is absolutely negligible compared with the bandwidth of the underlying links. Effectively, if you EtherChannel two Gig links you have 2 Gbps to play with.

Kevin Dorrell

Luxembourg

ValerioVale · ‎11-20-2007

Thanks Kevin for response,

but do you think that is possible to determine which is the traffic load on linking two switch by etherchannel?

I mean that I want use radios link between each port that partecipate to Etherchannel.

Kishore Chennupati · ‎02-20-2011

Hi Valerio,

I am assuming you are asking about load balancing across the link on the Etherchannel Since you are enquiring about this on a 3750 switch, please find below information in regards to this.

EtherChannel load balancing can use MAC addresses or IP addresses, source or destination addresses, or both source and destination addresses. The mode applies to all EtherChannels that are configured on the switch. You configure the load balancing and forwarding method with use of the port-channel load-balance {dst-ip | dst-mac | src-dst-ip | src-dst-mac | src-ip | src-mac} global configuration command.

You can find out which interface is used in the EtherChannel to forward traffic based on the load balancing method. The command for this determination is test etherchannel load-balance interface port-channel number {ip | mac} [source_ip_add | source_mac_add] [dest_ip_add | dest_mac_add].

Also find the below link which talks abit more about load balancing on ethernchannel

http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/release/12.2_25_se/configuration/guide/swethchl.html#wp1116754

HTH,

Regards,

Please rate if helpful