Specifications

Switching 8-13
Software Release 2.7.3
C613-03098-00 REV A
■ Connect 802.1q-compatible switches together through one port on each
switch
Devices that are members of the same VLAN exchange data with each other
through the switch’s switching capabilities. To exchange data between devices
in separate VLANs, the switch’s routing capabilities are used. The switch
passes VLAN status information, indicating whether a VLAN is up or down, to
the Internet Protocol (IP) module. IP uses this information to determine route
availability.
The switch has a maximum of 63 VLANs, or 255 for a Rapier i Series switch
ranging from a VLAN identifier (VID) of 1 to 4094.
When the switch is first powered up, a “default” VLAN is created and all ports
are added to it. In this initial unconfigured state, the switch broadcasts all the
packets it receives to the default VLAN. This VLAN has a VID of 1 and an
interface name of vlan1. It cannot be deleted, and ports can be removed from it
only when they also belong to at least one other VLAN. When all devices on
the physical LAN belong to the same logical LAN (same broadcast domain),
the default settings are acceptable and no additional VLAN configuration is
necessary.
Dynamic VLAN Assignment
Dynamic VLAN assignment allows a supplicant to be placed into a specific
VLAN based on information returned from the RADIUS server during
authentication. This limits the network access of a supplicant to a specific
VLAN that is tied to their authentication, and prevents supplicants from
connecting to VLANs for which they are not authorised. A port's VLAN
assignment is determined by the first supplicant to be authenticated on the
port.
VLAN assignment is enabled or disabled using the vlanassignment parameter
of port authentication commands.
The Configured and Actual fields of the show vlan command show which
ports are configured for the VLAN and which have been dynamically assigned
to the VLAN.
Radius attributes The RADIUS server provides information to the authenticator using RADIUS
tunnel attributes, as defined in RFC 2868, RADIUS Attributes for Tunnel Protocol
Support. The tunnel attributes that must be configured for VLAN assignment
are:
■ Tunnel-Type
The protocol to be used for the tunnel specified by
Tunnel-Private-Group-Id. VLAN (13) is the only supported value.
■ Tunnel-Medium-Type
The transport medium to be used for the tunnel specified by
Tunnel-Private-Group-Id. 802 (6) is the only supported value.
■ Tunnel-Private-Group-ID
The ID of the tunnel the authenticated user should use. This must be the
name or ID number of a VLAN on the switch.
These tunnel attributes are included in the Access-Accept message from the
RADIUS server to the Authenticator.