VMware Network Polices

VMware has a Network Policies that can be setup from the high level VSS to the single VMnic. There are two main setting. Load Balancing and Network Failover dections.

In this post I am going to go into what these options are and when you will use them.

Load Balancing

Here is the table from the VMware vSphere 5.1 online documents. Click here.

Option	Description
Route based on the originating port ID	Select an uplink based on the virtual port where the traffic entered the standard switch.
Route based on ip hash	Select an uplink based on a hash of the source and destination IP addresses of each packet. For non-IP packets, whatever is at those offsets is used to compute the hash.
Route based on source MAC hash	Select an uplink based on a hash of the source Ethernet.
Use explicit failover order	Always use the highest order uplink from the list of Active adapters that passes failover detection criteria.

Network Failover Detection

Option	Description
Link Status only	Relies solely on the link status that the network adapter provides. This option detects failures, such as cable pulls and physical switch power failures, but not configuration errors, such as a physical switch port being blocked by spanning tree or misconfigured to the wrong VLAN or cable pulls on the other side of a physical switch.
Beacon Probing	Sends out and listens for beacon probes on all NICs in the team and uses this information, in addition to link status, to determine link failure. This option detects many of the failures mentioned above that are not detected by link status alone. Note Do not use beacon probing with IP-hash load balancing.

The default selection is Route based on the originating port ID. This tell the traffic to send down the same vmnic until that network card has failed. Then it will look and the Standby Adapters.

Route based on IP hash. This allow the VSS or vDS to choose the best route. This requires multiple network cards to function correctly. This is very CPU intense.

Route based on source MAC hash. When the first packet is send, the network load is analyzed. From then on the traffic is sent out the same network card (MAC) until the adapter fails.

Use explicit failover order. Just as stated above. Use the highest listed vmnic. Then work your way down the list.

Now onto the Network Failover Detection.

Link status only is just as stated above. It checks the link for failures.

Beacon Probing is about checking of the health and connectivity between each vmnic (physical NIC) in the same vSwitch.