We have a very simple environment which is now entering the lifecycle.
There will be some new CISCO Switches and some new ESXi hosts. With us, the network team does the configuration on the physical switches (.i.a. configure the VLANs) We then do everything to do with vSphere.
Now to my question:
How can I test the connected VLANs on the new hardware.
How do you check as soon as the VLANs are configured on the ESXi, have connectivity?
I want to prevent that there are no interruptions when the first VMs are migrated to the new clusters
Assuming that the link from your switches to your ESXi host are Layer 2, you could created port groups on your VDSes or VSSes and tag them with the appropriate VLAN ID. Then create a VM, assign the port group that you wish to test to it's NIC, give the OS an IP address in that subnet and test network connectivity. If you can ping your gateway, you're good. If you can ping outside of your subnet, routing is good as well.