Speeding Up Networks with VLANS
A virtual local area network (VLAN) is a way to get computers on different network segments to communicate as if they were on the same local area network. This can be useful on networks with high network traffic. VLANs can reduce use of network bandwidth and increases security.
OS X Mountain Lion provides supports VLANs on Mac Pro machines, specifically supporting built-in Ethernet ports and secondary PCI gigabit Ethernet cards.
You set up and manage VLANs in the VLAN area of the Network pane of System Preferences. You must be logged in to the Mac as an administrator:
1. Open the Network pane of System Preferences.
2. From the Action menu (gear icon), choose Manage Virtual Interfaces.
This choice appears only if you have a Mac that supports VLANs, mainly a Mac Pro.
3. Click the Add (+) button and then select New VLAN.
4. In the VLAN Name field, enter a name for the new VLAN.
5. In the Tag field, enter a tag (a number between 1 and 4094).
This VLAN tag designates the VLAN ID (VID). Each logical network has a unique VID. Interfaces configured with the same VID are on the same virtual network.
6. Select the interface.
7. Click Create.
8. Click Done.