Mobile IP RFC 3344

[notes]
Mobile IP RFC 3344

The Home Agent (HA) contains the location database unlike the CUWN, the HA does not maintain a distributed database between WLCs. It does not query other HA’s
 The mobile IP client joining the WLAN does not provide the HA with any information. There are two methods of client notification of a roam event:

• Win OS L2 notification: Media Sense
• Foreign Agent (FA) advertisements: the FAs are forwarded to the HA so the HA can build a new tunnel to the new FA and proceed to forward packets to the client.

Several types of tunnels are available: GRE UDP IP in IP

Behind a NAT gateway = UDP tunneling

Typically, the foreign WLC modifies the destination MAC address of any packet from the wireless client to be its gateway MAC before forwarding it on.

DHCP option 68 can be used to convey the HA to the MN (Mobile Node)

Mobile IP client software manipulate the host’s forwarding table so that the lower metric interface is the mobile IP client interface