N7k Interconnection between Multiple VDCs .

[krishnadas.R_2]

Hi

I have 2 N7Ks

N7K-1 have 2 VDCs,  D1 and D2

N7K-2 have 2 VDCc  S1 and S2

D1&D2 have vPC configured between them  and S1&S2 also have vPCs b/w them.

What is the best practice to interconnect D1&D2 to S1&S2 with redundancy ?  I am yet to see a Cisco Doc that discusses this design, Please let me know your suggestions.

TIA.

[Reza Sharifi]

Never seen doc for a design like this, but why are you segregating your customers by VDC and then connecting them back together? What are you trying to do?

[krishnadas.R_2]

N7Ks are used at single customer site.

D1&D2 are collapsed core-dist switches (vdc), where access switches will connect and S1&S2 are server farm vdcs where fex's are attached.

7k1    7k2

S1------S2

D1------D2

[Bilal Nawaz]

Hello, So then you could do this:

Physically:

D1 to S1

D1 to S2

D2 to S1

D2 to S2

(not including the VPC peer or keepalives)

1)

From N7K1 and 2 Core VDC's

Have 1 VPC to N7K1-Access VDC

Have 1 VPC to N7K2-Access VDC

This means that your core will have VPC's but your access will have port-channels to your core and not vpc's.

And then have your N7K2's / FEX attached to this access layer.

D1 and 2 to S1 - VPC 1 on CORE

D1 and 2 to S2 - VPC 2 on CORE

or

2)

The other way, which I haven't quite tried before, but no reason why it shouldn't work...

You have D1 and D2 provide one VPC (a) to S1 and S2

You have D1 and D2 provide one VPC (b) to S1 and S2

In this scenario you would have x2 VPC's on the core, and x2 VPC's on the access.

D1 to S2 - VPC1 - both sides

D2 to S1 - VPC1 - both sides

D1 to S1 - VPC2 - both sides

D2 to S2 - VPC2 - both sides

Just be sure to enable peer-switch, peer-gateway, ip arp synchronize for the VPC domain for efficiency

hth.

[ERIK LAWAETZ]

Why not simply use FabricPath to interconnect them instead?

You avoid the concerns about routing across the interconnect that might arise with vPC, whilst maintaining the use of all redunant links for forwarding, and you get the rapid convergence of IS-IS.

Cisco FabricPath Best Practices is a good place to start.