Catalyst & Nexus

[salemmahara]

Hello everyone.

I couldn't find clear answer to these questions :

Can you tell me any rule about connecting Nexus and Catalyst switches together please?

I mean, is there any consideration or limitation ?

If you check Cisco website , you probably find both Nexus and Catalyst are introduced as core and data center switches.

Can you connect Nexus 9000 to catalyst 3850 ?( I know it's silly thing but can make it clear )

What does parent and child mean ? is it necessary to have parent and child ? I mean , can we use any switch as parent and child or they are specific models and must work with each other ?

Can you connect any Top Of Rack Nexus to any Core switch ( catalyst ) .

Thank you

:)

Why cisco recommend both Nexus and Catalyst as core ? I taught nexus series are only for data center and can not be Core ( interconnect LAN-WAN-Datacenter together )

[Mark Malone · Accepted solution]

Hi

Can you tell me any rule about connecting Nexus and Catalyst switches together please?

I mean, is there any consideration or limitation ?

They work well together , ios side as standard po and nx-os side as vpc po , integrate mostly without issues

Can you connect Nexus 9000 to catalyst 3850 ?( I know it's silly thing but can make it clear )

yes have it done currently we use 9k in and out of DC design as there very hardware powerful

What does parent and child mean ? is it necessary to have parent and child ? I mean , can we use any switch as parent and child or they are specific models and must work with each other ?

can you provide the context here , there are multiple parent child setups like hierarchical qos or 7-5 -2 ks design  , either way switches can be used as standalone anyway without any parent child scenario, but you cant use a fex alone as its a dumb switch gets its settings.info off the master either 5k or 7k depending on setup

Can you connect any Top Of Rack Nexus to any Core switch ( catalyst ) .

yes that's not an issue

Why cisco recommend both Nexus and Catalyst as core ? I taught nexus series are only for data center and can not be Core ( interconnect LAN-WAN-Datacenter together )

They were built for DC but are now regularly used in campus too , did they mean core DC and core campus or what exactly was specified in the doc you seen ? there is core 9k campus switches now too which are totally different than nexus 9ks

[Joseph W. Doherty · Accepted solution]

The major consideration might be understanding how vPC operates as using it correctly is a little more complex than using VSS.

I'm unaware of limitations of mixing Catalyst with Nexus, except those dictated by vPC technology usage restrictions.

"Can you connect Nexus 9000 to catalyst 3850 ?( I know it's silly thing but can make it clear )"

Sure. (BTW, why do you think it silly?)

Regarding your questions on parent/child, like Mark, could you further clarify?

"Can you connect any Top Of Rack Nexus to any Core switch ( catalyst ) ."

As far as I know, yes you can.

"Why cisco recommend both Nexus and Catalyst as core ? I taught nexus series are only for data center and can not be Core ( interconnect LAN-WAN-Datacenter together )"

Because they are powerful devices with many features. Generally, Cisco would push Nexus for DC related cores, as the Nexus feature set is more oriented to DC "things".

Likewise, Cisco would push the Catalyst for more generic/non-DC LAN routing usage, again due to feature orientation.