NXOS VPC 3750 to 3750

[Edip Gumuskaya]

Hi All,

We have a 2 x Nexus 7k in our main Data centre.

We have an offsite office connected via 2 x 10GB links.

Please see diagram attached

These links are connected to 2 x 3750 stacked switches and currently STP is blocking one port.

We would first like to port-channel the two links and apply VPC to them.

Our concerns are based around the recommended best practise between the CORE 3750 stack and the USER 3750 stack that are connected via a port- channel.

I can not see any best practise guides stating NX7K < VPC > 3750 < PO > 3750.

Any tips? Can anyone confirm whether this is best practise?

thanks in advance.

Ed

[richbarb · Accepted solution]

Hello Edip,

Will be hard to find some best pratice related to your topology, that's very specific.

There are a lot of docs about vPC, catalyst stack and port-channels, just put them all together in one scenario looking the many possible cases os failures.

As you did: NX7K < VPC > 3750 < PO > 3750.

Seems a good design for me.

Richard

[Edip Gumuskaya]

Thanks Richard,

I was hoping someone was going to point me to a section in the VPC best practise guide that I have re-read several times.

[Devavrat Oka]

Dual home the 3750 stack to the N7K pair. Split the uplinks between the 3750.

For eg:

7K-1 : Eth1/10 - 3750 : Te1/1/1

7K-1 : Eth1/11 - 3750 : Te1/1/2

7K-2 : Eth1/10 - 3750 : Te2/1/1

7K-2 : Eth1/11 - 3750 : Te2/1/2

On both 7Ks,

int eth1/10 - 11

switchport

channel-group 10 mode active

int po10

switchport

sw mod tr

sw tr all vlan

vpc 10

On 3750,

int ra te1/1/1, te1/1/2, te2/1/1, te2/1/2

channel-group 10 mode active

int po10

sw mod tr

sw tr all vlan

And then from 3750, do a Multi chassis etherchannel down to the other 3750 stack.

On both 3750s

int ra te1/1/3, te1/1/4, te2/1/3, te2/1/4

channel-group 11 mode active

int po11

sw mod tr

sw tr all vlan