Author: Valter Popeskic

Missing good old ‘wr’ command on N9K? let’s bring it back!

Doing a lot on Nexus 9000 series datacenter boxes (N9K) lately? Sure you’re missing the good old ‘wr’ command to save your last startup-config into running-config.

NXOS architecture guys decided that you should be really well concentrated when deciding to save your nice new configuration to survive device reboot and type: N9K_1(config)# copy running-config startup-config. Just typing ‘wr’ into the console would be too nice right? Let’s use the alias configuration and bring that command back to the box.

NSX-T Edge Transport Node Packet Capture

NSX-T v3.0.1 and v3.1.3 were used to try the stuff described below

As always with network engineers, even when working with SDN/SSDC solutions, sooner or later you will be asked to troubleshoot connectivity across your hops. And if working with VMware NSX-T platform, your next-hop for the North-South Datacenter traffic will almost always be NSX-T EDGE Transport Node VM. It will be really useful then to be able to get some packet traces out of that box in order to troubleshoot the traffic issues in detail.

One of the examples would be simple routing or some sort of Loadbalancing traffic that seems not to reach the backend hosts behind NSX-T edge.

On the NSX-T EDGE VM it’s fairly simple to capture traffic directly. It’s possible to get the output out on the console or to save it to the file on the EDGE and then pull it out with SCP.

If you have an EDGE Cluster, normally build out of 2 VMs, first, you need to see on which node the T0 or T1 router you want the traffic to be captured is active.

Let’s say we want to capture traffic on “T0-router” shown in the image below. You can go to that T0 router from the UI and check the High Availability Mode output:

NSX-T EDGE VM Active T0

VMware NSX-T Install Tips & Tricks

UPDATE on 13 Feb 2021:
There were some changes and improvements with version NSX-T 3.1, so some tips are no longer needed. I’m in the process of proving those notes myself, but it seems NSX EDGE VMs can be migrated now and EDGE VTEPs don’t need a separate subnet from HOST VTEPs anymore.

Intro

It’s a shortlist of things that you should probably know when installing VMware NSX-T. Of course, installing NSX-T should be done by following the official documentation. This here is just a few additional points that could help. It’s for your peace of mind afterward.

This is an article from the VMware from Scratch series

NSX Manager is a Cluster of three VMs

You should end up having three NSX-Manager VMs in a cluster when you finish NSX-T installation. The first one will be deployed via .ovf file from vCenter, the other two direct from first NSX Manager GUI as soon as you connect it to vCenter (aka. adding the Fabric -> Compute Manager)

VMware NSX-T Managers cluster

NSX Manager VMs should not run on the same ESXi host

Use vCenter datacenter configuration VM/host rules (affinity rules) to automatically keep manager VMs running on different hosts on the VMware environment. It’s about the host failing and you still having most of the managers running.

VMware TKGI – Deployment of Harbor Container Registry fails with error

This is an article from the VMware from Scratch series

During the process of preparation to Install Tanzu Kubernetes Grid Integrated Edition (TKGI v1.8) on vSphere with NSX-T Data Center (v3.0.2) one of the steps is to use Ops Manager to deploy Harbor Container Registry (in this case v2.1.0).

The process of deployment ended with Harbor error several times so I’m sharing here my solution in order to ease things out for you giving the fact that I didn’t come across any solution googling around.

VMware NSX TKGI K8S

Image from VMware website https://docs.vmware.com/en/VMware-Tanzu-Kubernetes-Grid-Integrated-Edition/index.html

In the process, the Harbor Registry product tile is downloaded from the VMware Tanzu network portal, imported in the Ops Manager installation dashboard, and selected to be configured and prepared for deployment into the VMware environment.

New ACI deployment? Watch out when connecting APICs to Leafs

It’s one of those articles aimed at the people with Cisco ACI experience who don’t bother with reading all the install and other guides again while going through n’th time of building and ACI fabric, like me. When it comes to Cisco ACI, you really should.

There’s a small change with the physical build of the third generation of APIC server where 10G SFP interfaces from APIC towards the Leaf switches (used for fabric discovery and later for the in-band controller to fabric communication) where 4x10G card is built in the server and not like 2x10G on M2/L2 and other first and second generation of APICs.

When you see those 4x10G ports on the server, the logical thing to do will be to use the first two ports on each APIC and connect them to two Leafs (for redundancy and stuff). It ended up being that is not really how Cisco intended those interfaces to be used and it will end up blowing your fabric stability and management. I was able to discover the fabric and register the fabric leaf and spines. It was even possible to configure the whole thing up to the functional fabric and L2-L3 functions but the APIC cluster was always unstable and going in and out of configuration stale and data diverged statuses on cluster view.