503| IP Mobility DellPowerConnect W- Series ArubaOS 6.2 | User Guide

Revocations

A home agent or foreign agent can send a registration revocation message, which revokes registration service for the
mobile client.Fo rexample, when a mobile client roams from one foreignagent to another, the home agent can send
a registration revocation message to the first foreign agent so that t he foreignagent can free any resources held for
the client.
Understanding Bridg e Mode Mobility Deployments
In bridgemo dedeployments, it is possible that more than one AP could be deployed in a singlelocatio n.Therefore,
APs in bridge forwarding mode support firewall session synchronization, which allows clients to retain their c urrent
session and IP address as they roam between different bridge mode APs on the same layer-2 network.
The bridgemode mobility feature facilitates client mobility on up to 32 layer-2 connected APs by allowing theA Ps
to communicate and share user state as the user roams from AP to AP. This mechanism is always enabled when an
AP is set to bridge mode, and it requires that all of the APs where roaming will occur be on the same Layer 2
segment.
Figure 157: BridgeMode Mobility
The roamingprocess o ccursas follows:
1. A client begins to roam from AP1 and starts an association with A P2.
2. A P2 sends a broadcast message to allA Ps on the locallayer-2 network asking if any other AP has a current
session state for the roaming client.
3. Only AP1 responds to the broadcast, and sendst hecurrent session table of the client.
4. A P2 acknowledgest hereceipt o f thes ession table.
5. A P1 deletes the session state of the client.
6. R oaming is complete.