Updates from QA Training

Network Health Check on vSphere Distributed Switches

vSphere 5.1 has introduced a lot of really useful functionality with the vSphere Distributed switches, Network Health Check helps avoid network setting inconsistency, which in turn avoids errors caused by misconfiguration


Bryan O'Connor | 19 February 2013

vSphere 5.1 has introduced a lot of really useful functionality with the vSphere Distributed switches, Network Health Check helps avoid network setting inconsistency, which in turn avoids errors caused by misconfiguration

I've been playing with the new features of the Distributed Virtual Switches in vSphere 5.1 lately as part of my prep for the vSphere 5.1 Optimise and Scale course .

One of the new features is a marvellous thing called Network Health Check.

The purpose of this feature is to detect certain issues and inconsistencies between the physical and virtual networks.

Certain key parameters such as MTU, NIC Teaming configuration and VLANs need to be configured consistently on the virtual and physical networks. If not we could then get some rather dramatic network connectivity issues.

What Network Health Check does is to search for these inconsistencies and report them to the administrator.

Network Health Check can detect and report the configuration differences between the port group and the switch port configuration by using layer two Ethernet packets. At one-minute intervals (by default), request and acknowledge packets are sent back and forth between the virtual interface and the switch. When packets are dropped, a configuration warning is displayed on the VMware vSphere® Web Client.

The requirements for Network Health Check include:

For VLAN and MTU checks, there must be at least two physical uplinks connected to the distributed virtual switch.

For the teaming policy check, there must be at least two active uplinks in the team and at least two ESXi hosts connected to the virtual distributed switch.

For a wonderful little demo visit the VMware Knowledge Base .

Bryan O'Connor

Senior Technical Instructor

Bryan O’Connor is a Senior Technical Instructor at QA, teaching VMware, Microsoft and CompTIA courses. In the past, Bryan has also been certified by Novell as a MCNI (Master Certified Novell Instructor). Bryan started in the world of IT in 1986 and has worked in a variety of roles ranging from PC support technician to Network design and consultancy, to Virtualisation consultant. At last count, Bryan held over 40 professional VMware, Microsoft, Novell and CompTIA certifications. Bryan has advised many large organisations on their IT and project management needs to allow them to benefit from the increase in productivity provided by computer systems. In addition to teaching, Bryan does a variety of jobs in QA, including supporting the sales staff and setting up the classrooms. Outside of QA, Bryan enjoys spending time with his wife Tracey and their two daughters Meagan and Jessica, unless there’s a grand prix on the TV when he enjoys paying Tracey, Meagan and Jessica to disappear for the day.
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