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Distribution Layer Necessary?

 
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Frequent Advisor

Distribution Layer Necessary?

We currently have 2 2848's operating as our core with 6-8 access switches and no vlans. I'm planning on adding a new core using 2 3500yl's with Adv License for inter-vlan routing and pushing the existing 2848's as a distribution layer so that I can use 24 port 3500yls' vs. 48 port to save costs.

My question is will there be any performance degradation or complications in the configuration with that type of setup, assuming VRRP at the core and MSTP/Vlanning?

Attached a diagram of the proposed setup.
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Honored Contributor
Solution

Re: Distribution Layer Necessary?

Hello,

you should provice enough links/ trunks from distribution to core. You should route at the distribution level, not core. If you route at the core, the whole traffic has to pass the distribution level. In this case, you can drop this level and attach the edge switches directly to the core.

Regards,
Patrick
Best regards,
Patrick
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Frequent Advisor

Re: Distribution Layer Necessary?

The 2800s at the distribution layer can't do inter-vlan routing/vrrp, and I don't have enough ports on the 3500s to get rid of the distribution layer. This setup should still work, I just want to make sure there won't be performance issues.
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Frequent Advisor

Re: Distribution Layer Necessary?

This will also be a mstp setup with different vlan priorities on different distribution switches to load balance and separate traffic.
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Honored Contributor

Re: Distribution Layer Necessary?

Hello,

in this case you should make sure, that the traffic is equal distributed over all uplinks to the core.

Regards,
Patrick
Best regards,
Patrick
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Frequent Advisor

Re: Distribution Layer Necessary?

Here is a link to a diagram containing the mstp information:

http://farm3.static.flickr.com/2709/4191026348_d4550742a6_o.jpg
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Honored Contributor

Re: Distribution Layer Necessary?

Hi,

nice setup. This should work.

Regards,
Patrick
Best regards,
Patrick
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Re: Distribution Layer Necessary?

Just a quick note: you shouldn't need to statically define instance priorities on the distribution layer, just the core (seemed like you were in the diagram).
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Frequent Advisor

Re: Distribution Layer Necessary?

How come?
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Frequent Advisor

Re: Distribution Layer Necessary?

I just assumed it would be necessary to define up to the distribution layer (not the access layer), otherwise wouldn't the access layer switches all route to one distribution switch instead of balancing between them?