3Com WXR100 3CRWXR10095A manual VLANs, IP Subnets, and IP Addressing, Users and VLANs

88CHAPTER 5: CONFIGURING AND MANAGING PORTS AND VLANS

VLANs are not configured on MAP access ports or wired authentication ports, because the VLAN membership of these types of ports is determined dynamically through the authentication and authorization process. Users who require authentication connect through WX switch ports that are configured for MAPs or wired authentication access. Users are assigned to VLANs automatically through authentication and authorization mechanisms such as 802.1X.

By default, none of a WX switch’s ports are in VLANs. A switch cannot forward traffic on the network until you configure VLANs and add network ports to those VLANs.

A wireless client cannot join a VLAN if the physical network ports on the WX switch in the VLAN are down. However, a wireless client that is already in a VLAN whose physical network ports go down remains in the VLAN even though the VLAN is down.

VLANs, IP Subnets, and IP Addressing

Generally, VLANs are equivalent to IP subnets. If a WX switch is connected to the network by only one IP subnet, the switch must have at least one VLAN configured. Optionally, each VLAN can have its own IP address. However, no two IP addresses on the switch can belong to the same IP subnet.

You must assign the system IP address to one of the VLANs, for communications between WX switches and for unsolicited communications such as SNMP traps and RADIUS accounting messages. Any IP address configured on a WX switch can be used for management access unless explicitly restricted. (For more information about the system IP address, see Chapter 6, “Configuring and Managing IP Interfaces and Services,” on page 103.)

Users and VLANs

When a user successfully authenticates to the network, the user is assigned to a specific VLAN. A user remains associated with the same VLAN throughout the user’s session on the network, even when roaming from one WX switch to another within the Mobility Domain.