In the most recent years, the area of mobile computing has developed enormously. Devices like PDAs, handhelds and digital mobile phones those ongoing gadgets of luxury have converted into a necessity in today's "always stay connected" routine. At this time Mobile IP came into picture to provide the portability without disconnecting. This allows the mobile node to use two IP addresses: a fixed home address and a care of address that change at every new point of connection. But with the advantages of Mobile IP also came the disadvantages, the biggest disadvantage that is security. When a device moves from its home network and enters a new network (foreign network), it has to change its IP address and re-establish a new TCP connection. If communication with this moving device occurs at that time, the communication has to be disconnected until a new IP address of a moving device is obtained. To solve this mobility issue, a working group within the Internet Engineering Task Force (IETF) proposed a solution, which is called Mobile IP Protocol. In this paper, we discuss a few of the common security threats that mobile IP networks are exposed to as well as some proposed solutions to deal with such threats.

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Mobile Node (mn) Home Agent (ha) Corresponding Agent (cn) Foreign Agent (fa) Mobile Host (mh) Communication Host (ch) Care Of Address (coa).