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Split Etherchannel Clusters

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".



Re: Split Etherchannel Clusters

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:

New Member

Re: Split Etherchannel Clusters

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.

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