I don't understand how a mobile node that has moved subnets can talk to the rest of the network when using proxy mobile ip. Does anyone know how this works?
ARP is L2(ish) and i get we don't want to create a giant L2 network by bridging all traffic both directions between an access point to the mobile node over the wifi link.
So we use mobile ip at the ip layer.
The problem is when a mobile node shifts subnets it is now on the wrong network.
The only thing i can think of is the AP intercepts all packets from mobile nodes and transforms them somehow. This turns an AP into router which it is probably underpowered to do, especially as the wifi side gets faster.