
122 Chapter 6: Metro Mobility: Client-Based Mobile IP
Home Network. Thus, if ingress filtering and uRPF are deployed in the network, a Mobile
Nodes might not be able to communicate with its peer.
To overcome the antispoofing mechanisms, Mobile IP uses a technique called reverse
tunneling, as defined in Request For Comment (RFC) 3024. With reverse tunneling, traffic
sourced from the Mobile Nodes is sent from the CoA back to the Home Agent through a reverse
tunnel, and then forwarded to its final destination from the Home Network. Now the source
address of the traffic is topologically correct. Figure 6-3 shows how reverse tunneling solves the
problem ...