Cisco Cisco Clean Access 3.5

This chapter describes how to set up subnet roaming for wireless clients. Topics include:

With roaming enabled, users can physically move between Clean Access Server-connected subnets 
without interruption of network connectivity. Roaming is transparent to users—they can continue to 
browse the Internet or use a network application without losing work if using a web application or having 
to log in again. 

A Clean Access Server supports roaming by identifying clients who have migrated from the range of an 
access point managed by another Clean Access Server. The new Server tunnels the traffic from those 
clients back to the original Server. 

When the user roams from one access point to another, the physical connection established by the 
wireless client is uninterrupted. Also, the client keeps the same IP address, so VPN connections do not 
have to be rekeyed. 

You can turn on roaming for Clean Access Servers selectively. That is, you can enable it for particular 
Servers and leave others disabled. Since a Clean Access Server can manage multiple subnets, you can 
also enable roaming by individual subnets. 

There are several requirements for the network to support roaming:

The access points for which you want to enable roaming must all have the same SSID. 

The access point signals need to overlap. Gaps between the signals will cause the user connection 
to be lost. 

Each Clean Access Server that supports roaming needs to be on a different subnet.