VLANs are typically created by an administrator, who then assigns switch ports to the VLAN. These are called static VLANs. If the administrator wants to do a little more work up front and assign all the host devices’ hardware addresses into a database, the switches can be configured to assign VLANs dynamically.
Static VLANs
Static VLANs are the typical way of creating VLANs and the most secure. The switch port that you assign a VLAN association always maintains that association until an administrator changes the port assignment. This type of VLAN configuration is easy to set up and monitor, working well in a network where the movement of users within the network is controlled. Using network management software to configure the ports can be helpful but is not mandatory.
Dynamic VLANs
Dynamic VLANs determine a node’s VLAN assignment automatically. Using intelligent management software, you can enable hardware (MAC) addresses, protocols, or even applications to create dynamic VLANs. For example, suppose MAC addresses have been entered into a centralized VLAN management application. If a node is then attached to an unassigned switch port, the VLAN management database can look up the hardware address and assign and configure the switch port to the correct VLAN. This can make management and configuration easier for the administrator. If a user moves, the switch will automatically assign them to the correct VLAN. However, more administration is needed initially to set up the database.
Cisco administrators can use the VLAN Management Policy Server (VMPS) service to set up a database of MAC addresses that can be used for dynamic addressing of VLANs. VMPS is a MAC address–to–VLAN mapping database.
