Concept Guide

Dell Networking W-Series Instant 6.5.1.0-4.3.1.0 | User Guide Mobility and Client Management | 338
Chapter 29
Mobility and Client Management
This chapter provides the following information:
l Layer-3 Mobility Overview on page 338
l Configuring L3-Mobility on page 339
Layer-3 Mobility Overview
W-IAPs form a single Instant network when they are in the same Layer-2 (L2) domain. As the number of clients
increase, multiple subnets are required to avoid broadcast overhead. In such a scenario, a client must be
allowed to roam away from the Instant network to which it first connected (home network) to another
network supporting the same WLAN access parameters (foreign network) and continue its existing sessions.
Layer-3 (L3) mobility allows a client to roam without losing its IP address and sessions. If WLAN access
parameters are the same across these networks, clients connected to W-IAPs in a given Instant network can
roam to W-IAPs in a foreign Instant network and continue their existing sessions. Clients roaming across these
networks are able to continue using their IP addresses after roaming. You can configure a list of VC IP
addresses across which L3 mobility is supported.
The Dell Networking W-Series Instant Layer-3 mobility solution defines a Mobility Domain as a set of Instant
networks, with the same WLAN access parameters, across which client roaming is supported. The Instant
network to which the client first connects is called its home network. When the client roams to a foreign
network, an W-IAP in the home network (home W-IAP) anchors all traffic to or from this client. The W-IAP to
which the client is connected in the foreign network (foreign W-IAP) tunnels all client traffic to or from the
home W-IAP through a GRE tunnel.
Figure 99 Routing of traffic when the client is away from its home network