Split Etherchannel Clusters

[john-daggett]

I am looking for documentation on how to set up a series of "split Etherchannel" connections. I believe that this can be done with 802.3ad (LACP), but I need some specific documentation on the subject.

In a split LACP environment, an Etherchannel group is divided between two core switches and those core switches coordinate L2 communication via an Inter-Switch Trunk. I need to be able to "layer" this configuration to create a "cluster of clusters".

See the attached diagram.

I need to understand the proper Cisco terminology for this structure, and I need a reference to documentation on how to set it up using 6500 switches as the "core".

Thanks.

[gpulos]

LACP is the IEEE, standarized, version of PAgP (ciscos proprietary portAggregationProtocol)

as with PAgP, LACP cannot be configured to create an etherChannel bundle of links divided across multiple switches.

a LACP channel must be comprised of ports with the same parameters, within a single chassis. you cannot create an etherChannel with 2 ports from SwitchA bundled with 2 ports from SwitchB to another endpoint(switch3).

see this link for more info on etherChannel configuration:

http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_guide_chapter09186a008007e6d3.html

[john-daggett]

Surely there must be a way to achieve what I have described with Cisco equipment. With Nortel switches there is a concept called Split Multilink Trunks that do just this. They allow access switch-1 to be connected to both core switch-2 and core switch-3 with both trunks in use simultaneously. This is part of what Nortel calls "Resilient Terabit Clustering" and they have a White Paper by that name describing it.

Are you saying that Cisco equipment can't do the same thing? I'd really rather use Cisco.