Root Switch - Distribution or Core?

I plan on implementing a FHRP on the Core Routers, with R1 being the active router. However I’m implementing STP right now but was just asking for advice on whether I should be making one of the core switches the root switch, or follow Odom’s advice and go with a distribution layer switch? It seems to me that it would obviously make more sense to go with a core switch, but I didn’t want to second guess Odom. Is there a particular reason why he recommends using a distribution switch as the root switch?

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networker050184

Why bring STP all the way to the core? I'd go straight layer 3 from dist to core.

d4nz1g

Keep your layer 2 at the distribution/access and implement FHRP on the distribution.

Look for campus network design best practices.

ednard

networker050184 wrote: »

Why bring STP all the way to the core? I'd go straight layer 3 from dist to core.

You’d recommend just running STP from acc. to dist. and then just implementing a FHRP to connect the dist. to the core?

d4nz1g wrote: »

Keep your layer 2 at the distribution/access and implement FHRP on the distribution.

Look for campus network design best practices.

I’ve modified it and it now looks like so (below). I guess this removes the original dilemma I had and makes it simpler. Found a Cisco Campus Design Best Practice manual, so I’ll give that a study. Thanks.

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networker050184

No, the FHRP is on the dist for host gateway. Dist to core is a layer 3 link running a routing protocol with the dist.

ednard

networker050184 wrote: »

No, the FHRP is on the dist for host gateway. Dist to core is a layer 3 link running a routing protocol with the dist.

Sorry, I'm not 100% with you. I should be adding distribution layer routers to then link with the core layer routers, or would you advise I used layer 3 switches instead of my current distribution layer switches, and then run layer 3 links to the core routers?

networker050184

Layer 3 switches at dist and core. If you don't have the budget, need, etc to go with L3 there I'd then just go with a collapsed core/dist design and do a way with that layer of switches all together. It's a bit overkill anyway with only five access switches if this diagram is accurate.

theodoxa

The Core should be Layer 3 only. Basically, you have a switch block with N Access switches. Those Access switches are connected with Layer 2 trunks to 2 Distribution switches. You would implement an FHRP on the 2 Distribution switches to provide redundant gateways for the various VLANs in the switch block. The Core which connects the switch blocks together would be Layer 3. STP, VLANs, and any Layer 2 Protocol would never go further than the Distribution Switches.

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