can we use Nexus 9300 in this topology (N2k--->N9300--->N7k)

[S. B]

Hi,

This is question is for all switches in  NX-OS 

our current network is N2K--->N5K--->N7K (all vpc and layer 2) , gateway is N7K or upper layer firewall after N7K)

We are not moving to ACI,

We are keeping on the NXOS mode.

As Cisco has replaced Nexus 9300 with the Nexus 5K series, can we replace the Nexus 9300 with the Nexus 5K , without changing topology ?

(N2k--->N9300--->N7k)

i didnt find any documents that says we can use Nexus 9300 with the common topology (N2k--->N9300--->N7k) all layer 2 and VPC.

what was confusing me was that , even in NXOS mode, should the topology of the Nexus 9300 be leaf/spine?

or its not important , and we can use the same topology that we used in N2K--->N5K--->N7K?

Thanks

[Sergiu.Daniluk]

Hi @S. B 

Yes, you can use the Nexus 9300 as replacement for N5k in your topology.

Depending on the model, you can use the N9K as EOR, TOR, MoR:

https://www.cisco.com/c/en/us/products/collateral/switches/nexus-9000-series-switches/guide-c07-730115.html#_Toc387967222 

Regards,

Sergiu

[S. B]

Hi, Thanks

This Link is using Nexus 9300/9500 in ACI mode , not in NXOS mode

Im looking as a replacement of Nexus 9300 with Nexus 5696Q in NXOS mode, without changing the topology.

I have attached the current diagram (N2K-->N5k-->N7K) , which only N5K will be removed and Nexus 9300 will be replaced.

I havent seen this topology in the link.

[Alex.M]

Hi S.B,

This depends on the type of ASICs being implemented.  You can generally tell what ASIC family is being implemented by looking at the last two letters in the switches (93180YC-EX and Cisco Nexus 93108TC-EX as for example).  You can verify if a  9300 model supports your FEX hardware by visiting this page below.  Pay attention to code type (ACI or NXOS) as well as minimal release version:

https://www.cisco.com/c/dam/en/us/td/docs/Website/datacenter/fexmatrix/fexmatrix.html

To address your question regarding if a spine/leaf architecture is required for the Nexus 9000 series switches running in NX-OS mode.  Line-rate VxLAN is one of the powerful capabilities of the platform and that's why it's commonly the poster child of Nexus 9k topologies but don't be fooled into thinking it's the only supported topology.   Depending on your ASIC, the Nexus 9k series supports most if not all the topologies that the Nexus 5696Q could (and more).

For your specific topology, so long as the 9300 platform selected supports the FEX attachment, you will be golden.

Hth,

Alex

[S. B]

Dear @Alex.M 

Special Thanks

This is the exact current topology : A classic DataCenter Network Topology (N2K,N5K,N7K)

• All connections Layer 2 .
• Server to Fex = etherchannel , vPC
• Fex to N5696Q = straight through connection (Etherchannel)
• N5696Q to N7K = vPC
• L2/L3 Boundry = N7K

 

Now, the exact solution is that, the following Nexus 9300 switches are going to be used instead of Nexus 5696Q for the expansion of the Datacenter switches , because the N5696Q is going to be EOS/EOL @ May 2021, and the DataCenter topology wants to remain same as before. (Migration to ACI is not the current plan, but can be done later due to the compatibility of the devices) 

Nexus 9300 devices that are going to be used instead of the N5696Q (as parent switch).

N9K-C9336C-FX2 , 36 x 40/100 QSFP28)                       This switch supports Fex 2348UPQ in NXOS mode

&

N9K-C93240YC-FX2, 48 x 10/25G + 12 x 40/100G         This switch supports Fex 2348UPQ in NXOS mode

&

N9K-C93360YC-FX2  96 1/10/25G + 12 x 40/100G        This switch supports Fex 2348UPQ in NXOS mode

So, the New topology will look like this:

The question is that:

Is there any problems with this solution? I mean as the current solution was working with N2K-->N5K-->N7K, will it work with N2K-->N9300-->N7K, all in NXOS mode , as the topology shows?

Are there any considerations that need to be taken?

For example, i found the 3 following considerations:

- Mostly Straight-Through connection between Fex and N9300 is required(No problem)

- Nexus 9300 only supports 16 x Fex (should be considered)

- FET cable is not supported between N2348UPQ and N9300 (should be considered)

Are there any important ones that you might remember?

I found the following links that help on the considerations and configurations between N2K and Nexus 9300.

Are there any more that you might know?

Cisco Nexus 2000 Support for Cisco Nexus 9000 Series Switches

Cisco Nexus 2000 Series NX-OS Fabric Extender Configuration Guide for Cisco Nexus 9000 Series Switches, Release 7.x 

Cisco Nexus 2000 Series NX-OS Fabric Extender Configuration Guide for Cisco Nexus 9000 Series Switches, Release 9.3(x)

Cisco Nexus 9300 Release notes

Cisco Nexus 9000 Series NX-OS Release Notes, Release 9.3(4)

Recommended Cisco NX-OS Releases for Cisco Nexus 9000 Series Switches

Verified Scalability Considerations on Nexus 9300

Cisco Nexus 9000 Series NX-OS Verified Scalability Guide, Release 9.3(4)

[RedNectar]

@S. B ,

It looks like you have done all the work and identified any shortcomings!

In a spot like this, you can usually talk to your Cisco rep and make sure that they will validate the design before you place the order, but I see no problem with it.

My suspicion (based on your other question) is that you started down this path and had ACI suggested as "the way to go"

:)