Nexus 7K as Core switch with Catalyst in the distribution layer

[TrickTrick]

Hello,

I want to understand, from a design perspective, how a nexus 7k switch can be connected to catalyst switches in the distribution layer 

N7K will be used as core and DC switch at the same time (by using VDC I guess)

What are the possible designs using those references, especially the interconnection between the dist and N7K (L3 etherchannel, L2 etherchannel (catalyst side)? vPC N7K side ?

I'm a bit confused because in such scenario is new to me

Thank you in advance for your thoughts, any document would be helpful

[balaji.bandi]

If this enterprise Lan, Nexus is not the right choice, this is more of DC-based Switches.

This is not a commonly recommended design as per the Cisco standards, i do see people deploying like this with their own choices.

If Nexus 7K can able to handle everything you looking to achieve in terms of routing and other stuff based on the requirement.

i will advise layer2 connection to Catalyst switches. (not sure what model here in your environment) - the catalyst switches required a base License you save some cost here.

Other Option, If the catalyst switches powerful like Cat 9500 with network advantage License, then you can make them Layer 23 between Nexus and Catalyst,

Note: the decision to be made based on the requirement and where you like to have Layer 3 and Layer 2 demarcation before your deployment take place.

[TrickTrick]

Hi Balaji,

The choice is already made, access switches are 9200, and distribution are 9500 switches

in the DC layer will be hosted all the servers (application servers, WLC, ISE ...), and I think there will be VDC in N7K to separate the core switch function for the lower layers (will host vlan interfaces as gateways), and DC part

now, between Catalyst and N7K what are the available choices ? and what can I do between VDCs? those are my main questions to understand well what could be achieved

[balaji.bandi]

If there is no Layer 2 Extention required. Then My take will be Layer 3 between Cat 9500 and Nexus.

ISE  / DNS other stuff can be reached over Layer 2 network, I would be more interested to see where your WLC, (i would advise connecting to Cat 9500 ) - if you going Layer 3. between nexus and catalyst.

[TrickTrick]

There are 2 different buildings, each has a stack of 9500 and access
switches, n7k are located in a different building which will host the DC
So n7k switches will be connecting all the servers (wlc ise etc...) and i
think we will put l2 between n7k and catalysts, i need to know what is
recommended on such scenario, l3 etherchannel with vpc n7k side? Or
something else..

[balaji.bandi]

There are pros and cons - so as per your information, you like to extend the VLAN, so you need to build a Layer 2 port-channel here.

and allow all the VLAN required in the port-channel.

Nexus will have all the Layer 3 SVI here..

Suggest making a small network Digram for reference to show where the service is located, you will see a clear picture.

[TrickTrick]

Yes but n7k side then ? It will be vpc with FHRP ( n7k's redundancy) ?

[balaji.bandi]

Yes but n7k side then ? It will be vpc with FHRP ( n7k's redundancy) ?

Suggest making a small network Digram for reference to show where the service is located, you will see a clear picture.

You have to provide more information, I have advised high-level information here.

as mentioned you need to give us more information, How many nexus, how many Cat 9500, is the cat 9500 in SVL?

is your access  switches to be Dual Homed with Cat 9500 

VDC is just splitting the switch into different services,