VSS - VSL requirements

[shamg1974]

I have 2 6509's with the following Supervisor Engine:

VS-S720-10GE-3C

I also have 2 WS-X6704-10GE modules that were recently purchased. I'm a bit confused as to whether I can do VSS with my current hardware.

Can I just run the VSL off of the 2 10GB ports on Supervisor module? I understand best practice would be to perhaps have an extra port from another line card as well, but I don't really want to return the card for the 8-port module.

I read that theres a different ASIC in the 8-port card and that the 4-port card won't work.

Any help on this is greatly appreciated.

Bobby Grewal

[Jon Marshall · Accepted solution]

Bobby

Yes you can run the VSL link purely off the supervisors although as you mention it is better to have the VSL link spread if possible.

The 6704 as you say won't support the VSL link but will work happily in a VSS setup.

Jon

[Reza Sharifi · Accepted solution]

Bobby,

To add to Jon's comment.  The number of queues are also different between the 10Gig on the sup and the line card.  I beleive, it is 4q vs 8q on the module.  It is a good idea to do one from the sup and one from the module. Also, if you have the option to change the 4 port 10Gig to 8 port, I would go for it.

HTH

Reza

[shamg1974]

I understand best practice...but I have a customer who has limited funds....If I don't have to swap out the 4-port card with the 8-port card, I don't want to.

Can I run VSS and VSL with the existing hardware I have? Jon's response tells me I can, which I trust as he has posted for me many times. Do you have information or experience that would contradict this?

[Rahul Kachalia · Accepted solution]

Hello Bobby,

Yes, you can certainly use both 10G port from supervisor to build VSL EtherChannel between both supervisor. It is definitely supported and a valid design, just following two key points to keep in mind :

- Restricted VSL Capacity = If you need to expand beyond 20G VSL capacity then you will need VSL capable linecard, i.e. 6708/6716. If you are going to use Sup2T then you can use with 6908 or 6816. Commonly required to handle data traffic load with integrated services-module

- Common ASIC = Since internally both 10G uplinks are common fabric/ASICs if any internal failure occurs then it may impact both VSL ports and may cause Dual Active condition in network. Rare condition but you may want to keep this point in mind.

From QoS perspective, you will not loose anything between using VSL ports from supervisor OR diversified between supervisor and VSL capable linecard...

thanks,

rahul.