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MOBILE IP. Mobile IP is the underlying technology for support of various mobile data and wireless networking applications. It is designed by IETF. Need a protocol Protocol to enable mobility must not require massive changes to router software, etc. Must be compatible IPv4 networks/hosts.
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MOBILE IP • Mobile IP is the underlying technology for support of various mobile data and wireless networking applications. • It is designed by IETF.
Need a protocol • Protocol to enable mobility must not require massive changes to router software, etc. • Must be compatible IPv4 networks/hosts. • Confine changes to mobile hosts and a few support hosts • Just hacking DNS won’t work • – DNS updates take time • – Hooks for normal users to update DNS won’t be accepted by administrators. • – After DNS lookup, raw IP address is used by TCP, UDP. Why Mobile IP ?
Mobile IP Operation • Sending and Receiving Packets • Discovering the care-of Address • Registering the care-of address • Tunneling to the care-of address • Deregistering the care-of address
Roles of Mobile IP • The Foreign Agent • The Home Agent • The Mobile Node
Routing in Mobile IP Corresponding Node CN Packet from mobile Triangular Routing Global Internet Packet to mobile Mobile Node Home Network Visited Network Home Agent Foreign Agent Mobile IP forward tunnel Care of Address
Routing in Mobile IP Corresponding Node CN Packet from mobile Reverse Routing Global Internet Packet to mobile Mobile Node Home Network Visited Network Home Agent Foreign Agent Mobile IP forward & reverse tunnel Care of Address
Security ???? Bogus registration Send Packet To ME Evil Thing Home Agent Registration Request
Security Replay Attack ???? Home Agent digest Captured Registration is retransmitted
Issues with Mobile IP • Mobile node and correspondent node are on the same sub-network. • packets in Mobile IP to mobile host are routed through Home Agent. • packets travel a longer path • Routing in Mobile IP is asymmetric and is termed as triangular routing • Mobile Node to any Internet host can be routed directly but all the packets to Mobile Node go through Home agent. Inefficient Routing
ARP Resolution • IP is logical address for communication link level address is required. • Link level Address is also Called MAC Address. • IP addresses are resolved into physical address using ARP (Address Resolution Protocol). • To resolve the problem of ARP uses two Cases I. Proxy ARP II.Gratuitous ARP
Ingress Filtering • Mobile IP results in triangular routing . • Many Firewalls deploy ingress filtering. • If the reply path is not same then packet will be Drop So answer Of this problem is Reverse tunneling. • The mobile Node are tunneled back to Home Agent after Foreign Agent receives them.
Abbreviations and Concepts 3GPP 3GPP2 AAA BGP CDMA 2000 DIAMETER DHCP DMZ FA FW