Cat6500 Etherchannel Across Line Cards to Seperate Fiber Rings

Unanswered Question
Jun 19th, 2007

Hi Folks,

Couple of questions.

1) Do the 10GE modules support etherchannel? I assume no.

2) Real question...We have a city laying fiber in a two rings (not sonet, just terminated with edge switching like 3750's and 6500). The dual rings are provided for redundancy. Most of the locations, especially the core location that has/getting a brand new Cat6500, will have 1GE connections to each fiber loop. At the core 6500, can I etherchannel across two 16GB-port line cards to each ring? My first concern is that each ring may not have exactly the same length/roundtrip time, so I was not sure if that would have an affect. Also, I obviously need to consider STP and routing issues, but the etherchannel question in general is top of mind.

Please advise.


Dennis G.

I have this problem too.
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pciaccio Tue, 06/19/2007 - 10:21

To answer your questions:

I would believe that 10G ports support Etherchanneling. They are using the 802.3 Ethernet protocol. Etherchanneling runs on top of that protocol . However I'd refer to the Cisco Tech site for the specific 10G card you have and see if it is compatible.

To answer the 2nd question, I would assume that your two rings are carrier provided in your city and they would probably provide to you a Dot1Q in Q tunnel. This allows for a transparent tunnel within a tunnel that the carrier provides. You are then allowed to etherchannel on this tunnel. The length would not be a major issue unless the time differences are dramatic. In etherchannling STP functions on the aggregate as one link, so you will not see any issue running STP through your channeled links... Good Luck...

dennis.griffiths Tue, 06/19/2007 - 10:42

Thanks! Good points. The fiber infrastructure is essentially going to owned by the city with a hop off point to the provider for internet access, so I'm not sure I have too many restrictions on what I can do.

Appreciate the reply.


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