4500x Design

[phanegraaf]

                   We recently have purchased two 4500x series switch and I am wondering best pratice for cabling. We will be runing VSS. Should I cable each physical 4500x's uplinks to seperate Nexus 7k's or cable each 4500x switch to the same 7k? We will have two 10 gig uplinks coming from both 4500x switches

Thanks,

PH

[sean_evershed]

If the single N7K fails then you have lost connectivity to your core. For redundancy therefore I would cable to both N7Ks.

[Seb Rupik]

Hi there,

To provide proper redundancy, you will want to create port-channels which span the Nexus vPC and connect to a single 4500X.

NexusA eth1/1 -> Po2 (vpc2)

NexusA eth1/2 -> Po3 (vpc3)

NexusB eth1/1 -> Po2 (vpc2)

NexusB eth1/2 -> Po3 (vpc3)

4500X-a -> NexusA eth1/1

4500X-a -> NexusB eth1/1

4500X-b -> NexusA eth1/2

4500X-b -> NexusB eth1/2

...sorry for not drawing a diagram!

cheers,

Seb.

[phanegraaf]

OK, That makes since. Your recommendation is how I currently have it setup. There has been some debate internally wether we should connect each physical 4500x to the same 7k as I illistrated below.

4500X-a -> NexusA eth1/1

4500X-a -> NexusA eth1/2

4500X-b -> NexusB eth1/1

4500X-b -> NexusB eth1/2

Thanks!!

[Seb Rupik]

As Sean pointed out, if you lost a one N7K, any singly attached hosts connected to its downstream 4500X would be lost.

Your current design is correct.