Even if you are new to VMware vSphere, you may not be new to the concept of NIC teaming. If you are, have no fear, we are about to take a look at NIC teaming, and some ways it can be implemented in VMware vSphere 6.5.
NIC teaming is simply combining several NICs on a server, whether it be a Windows based server or a VMware vSphere 6.5 host. Why would we do this? It really boils down to two reasons:
- Redundancy. My server will be able to survive a NIC card failure or a link failure and continue to pass traffic.
- Load Balancing. My server will be able to pass traffic on multiple NIC cards. If the server is busy, the traffic will not overwhelm a single NIC card, because it will be distributed in a manner we choose.
If we look at the configuration options on a standard virtual switch, or vSwitch, we will see the two important things in the Teaming and Failover settings: load balancing options and failover order.
As you can see, there are four options to chose from in a standard vSwitch:
- Route based on IP hash
- Route based on source MAC hash
- Route based on originating virtual port (the default option)
- Use explicit failover order.
If we are working with a distributed virtual switch, we would also see an option called Route based on physical NIC load, which you can learn more about here. Remember, a distributed virtual switch requires VMware vSphere Enterprise Plus licensing.
First we will take a look at the simplest of the Teaming and Failover options in a standard virtual switch, Use explicit failover order. With this option, there is not any load balancing performed. See the list off active adapters? With this “load balancing” method, VMware vSphere will simply use the first adapter in the active list. If this adapter fails, it will use a standby adapter.
Why would this setting be used? Let’s say I had two NICs available for management and vMotion, and I needed to use a dedicated NIC for each. I would still want to provide some level of redundancy, so for the Management potrgroup I would use vmnic1 as active, and vmnic2 as standby. For the vMotion port group I would use vmnic2 as active and vmnic1 as standby. This way if either NIC or link failed, I would still have both Management and vMotion traffic operating on my ESXi host.
As you can see by this Management port group configuration, the Teaming and Failover options of the switch can be overridden for each port group by checking a box.
There is a lot to consider when designing a VMware vSphere network, and the technical details behind it are just one small part. If you want to get in the right mindset to start the vSphere networking design process, be sure to read this article on vSphere Networking Design Choices.
Stay tuned, because there is more to discus with vSphere networking and NIC teaming! We are also going to explore:
- Route based on originating virtual port and Route based on physical NIC load methods.
- Route based on IP hash and MAC hash load balancing methods.