ISL between Nexus9000 C9372TX and Nexus 9336C-FX2

[utawakevou]

We currently employ two Nexus9000 C9372TX hosting our three-tier architecture VMware infrastructure with vPC for redundancy and load balancing, core routing/switching and acting as our root bridge. HRSP and OSPF routing is configured and enabled as well

We are moving to a hyper-converged infrastructure using Lenovo ThinkAgile VX7531 Certified Node with a Cisco Nexus 9336C-FX2 that’ll host our HCI and we will need to have an ISL between the new switch and the current Nexus. We’ve got a couple of QSFP-40G-SR-BD modules and was wondering if this is compatible and can be used for ISL fibre link between the Nexus9000 C9372TX and the Nexus 9336C-FX2 ?

Since the new switch will be running on NX-OS software I do believe it’ll be the same command syntax as the current Nexus with vPC and other necessary configuration. Just need confirmation on this.

With the spanning tree design, I’m thinking of using the new switch as my root bridge. Is that a good or bad design?

Any configuration examples on the above setup or any other tip to get this done properly and maintaining our redundancy, load balance etc will be really appreciated.

[M02@rt37]

Hello @utawakevou,

Please find here the compatibility with QSFP-40G-SR-BD and N9k.

https://tmgmatrix.cisco.com/?si=QSFP-40G-SR-BD&tpid=151&npf=74

The command syntax and configuration, you are correct that the NX-OS software on the Nexus switches will have a similar command syntax.

As for the spanning tree design, it's generally recommended to have a single root bridge for the spanning tree topology to maintain stability and consistency. In your case, using the new Nexus 9336C-FX2 as the root bridge could be a valid design choice, especially if it will be hosting the HCI. Just make sure to adjust the spanning tree priority on the switches accordingly to determine the root bridge election.

To maintain redundancy and load balancing, you can consider configuring vPC between the Nexus 9000 switches and the Nexus 9336C-FX2. This will allow you to create a logical link aggregation between the switches, providing redundancy and load sharing. Ensure that you follow the vPC configuration guidelines and best practices provided by Cisco for your specific Nexus switch models and NX-OS version.

[utawakevou]

Thank you  M02@rt37 for the valuable insight. That matrix is really helpful.

[MHM Cisco World]

Can you draw the topology you want to config 

[utawakevou]

See attached. I've got WAN and borders routers as well distributed to the N9K-C9372TX using L3 configured ports for redundancy (OSPF) etc. Not in this diagram. My plan is to connect my Distribution Switch (HP/Aruba 3810m-16sfpp) via fibre using HP SFP J4859C is a 1000Base-LX transceiver module which I hope is compatible with QSFP-40G-SR-BD.

At the moment I've got a an old stacked Cisco3750 with UTP ISL to N9K-C9372TX using vPC and etherchannel (not in the diagram). Plan is to decommission the stacked Cisco 3750 and have the design as per attached diagram

Let me know if more information is needed.

[MHM Cisco World · Accepted solution]

It easy this design called double sided vPC' I will write some note in your topolgy 

MHM

[utawakevou]

Anyone can give me a link for the NX-OS upgrade path. Device came with version 9.3.6. I follow this path and currently on 10.1.1. 9.3.6>9.3.11>10.1.1

When I ran the "show install all impact" for 10.1.2.bin it fails to process the NXOS image. Pre-upgrade check failed.... My plan is to install the latest version i.e., nxos64-cs.10.2.5.M before start with my configuration etc and deployment.

[utawakevou]

File downloaded must have been corrupt. Done the MD5 Checksum and it failed. Another file downloaded and it works. Lesson learned, always do the checksum against the value in the file details..

[utawakevou]

I've managed to set this up using double sided vPC. Current N9K-C9372TX still my root bridge and I've setup the Nexus 9336C-FX2 as my second priority root bridge. Thanks @MHM Cisco World for that tip