Blue Gears - 3 Physical NICs with VMware ESX

Virtualization running on hosts with only 2 on-board pNICs and 1 pNIC in a slot have security, redundancy, and performance challenges. Administrators are forced to make choices on how much redundancy is required and where to place it. How to setup virtual networking when 3 pNICs are involved follows:

pNIC0 -> vSwitch0 -> Portgroup0 (service console)
..................-> Portgroup1 (VMotion)
pNIC1 -> vSwitch0 -> Portgroup2 (Storage Network)
pNIC2 -> vSwitch0 -> Portgroup3 (VM Network)

When only 3 pNICs are available there is no good way to establish redundancy using two vSwitches so it is best to use all three pNICs within a single vSwitch. This allows you to use all three pNICs for different purposes but still allows the vSwitch to handle redundancy cases. For example, in this situation I would setup each portgroup to have its own fail over setup where each pNIC unused by the portgroup is a stand-by adapter for that portgroup. In other words, pNIC1 and pNIC2 would be stand-by adapters for portgroup0 and portgroup1; pNIC0 and pNIC2 would be stand-by adapters for portgroup2; and lastly pNIC0 and pNIC1 would be stand-by adapters for portgroup3. This configuration works better when VLANs are involved and trunked to the vSwitch but it can work with subnets just as easily. If there is no storage network involved or a FC-HBA is in use, then pNIC1 would move to be the pNIC for the VMotion portgroup. However, if an IP storage network is involved then you want to segregate storage traffic as that is a constant amount of traffic where VMware VMotion is only used periodically. This setup will give the best level of redundancy, security, and performance for each network involved on the VMware ESX or ESXi host.

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