With the announcement of vSphere 5.1, one of the new features announced was the network health check feature now available for Distributed Virtual Switches (version 5.1 of the switch). This area has already been covered in detail by two bloggers I know of, namely Chris Wahl at Wahlnetwork, and Rickard Nobel.
However, this is one feature I was really looking forward to testing out myself, and had been preparing for by getting some physical Microserver Hosts up and running in my home lab with multiple NICs and VLAN support. The other day I had a chance to play around with the Network health check functionality with one of my hosts uplinked to a DVS I had created in vCenter.
This evening I was reminded of how useful this feature actually is. I had plugged one uplink from my Dell PowerConnect 5324 switch into the dual port NIC in the host and left the other NIC disconnected as I was short one cable. Tonight (a day later) I connected this up and was immediately notified of an issue on the uplink with the VLAN health status! I had of course, forgotten to setup the port trunking on the Dell switch (VLANs 8 and 10) after having set this up yesterday for just the one port that was connected.
Here is a breakdown of what I saw using the vSphere Web Client after selecting my DVS and then choosing the Health tab under “Monitor”. (vCenter also has alarms set up when you enable the feature that show to alert you of the issue).
A quick change on my switch to set the VLANs up on this particular uplink port meant I was soon up and running again.
As you can see the Health Check feature is really useful, providing vSphere admins with an easy way to check network port configurations on the networking hardware without having to login to another interface and check themselves, or rely on another team to do this for them. For more detail, or instructions on how to set this up, I recommend checking out the two blog posts I linked to above by Chris Wahl and Rickard Nobel.