Gmap Overview; Configuring Gmap; Enabling And Disabling Gmap - Alcatel OmniSwitch 6800 Series Network Configuration Manual

Using Interswitch Protocols

GMAP Overview

The Group Mobility Advertisement Protocol (GMAP) enables workstation users to move from port to port
among interconnected switches and still retain all learned mobile port and protocol information. Using
GMAP, the switch that receives a GMAP update packet updates its internal GMAP tables and queries the
forwarding database to make any necessary updates.
At startup time and for three successive update intervals, GMAP sends update packets on all virtual ports
that are active non-leaf ports (that is, ports that are running Spanning Tree). After startup and three trans-
missions, interval packets will only be sent on virtual ports that are active and are known to have an
OmniSwitch or OmniS/R running GMAP connected to them.
GMAP will send updates only for MAC addresses that are learned on leaf ports (ports that are not running
Spanning Tree). It does not advertise MAC addresses for VLANs assigned by authentication or binding
rule classification, and it does not advertise VLAN 1 entries. If conflicting information is received for a
MAC address, the last packet received for that address will take precedence.
When the switch learns a new MAC address on a mobile leaf port, it attempts to assign it to a VLAN. It
consults GMAP tables and any appropriate VLAN membership entries are added to the forwarding data-
base.

Configuring GMAP

GMAP is inactive by default. In addition to enabling and disabling GMAP, you can configure the time
between packet transmissions (when multiple packets are required for an update), the time between
updates, and the length of time GMAP will retain its current information.

Enabling and Disabling GMAP

To display whether or not GMAP is active or inactive, enter the following command:
-> show gmap
To activate GMAP on the switch, enter the following command:
-> gmap enable
To deactivate GMAP on the switch, enter the following command:
-> gmap disable
OmniSwitch 6800 Series Network Configuration Guide November 2004
GMAP Overview
page 8-9