Bit stumped by this one… could mean lots of things. Off the top of my head:
Web Client – Networking – select the dvSwitch you want to check and then Manage – Settings – Health Check, click edit and enable the VLAN and MTU and Team and Failover checks:
This enabled the healthcheck which then allows you to go to the dvSwitch – monitor – Health and get a nice screen that is checking VLANs are trunked, MTUs are ok and that the Teaming and Failover settings are uniform:
Suppose this could really be asking about some log insight bits and pieces, could be talking vROPs or vRNI as well, or within NSX in particular might be worth checking the service status on hosts, NSX Manager etc. etc.
Suppose the moral of the story with these types of objectives is it could be anything really… fingers crossed I have played around with NSX enough to cover troubleshooting!!