\abstract{We have built an experimental link-level authenticated ad hoc
routing protocol and integrated it with the PSU version of Mobile-IP.
The routing protocol is intended to address survivability and link
security issues.  In our modified version of Mobile-IP, we authenticate
ICMP router discovery packets, which are sent by both Mobile-IP
agents and mobile nodes.  The router discovery packets allow systems
to exchange authenticated MAC and IP addresses.  Topology problems
caused by tying IP subnet schemes to routing on radio links are
solved.  The security problems associated with ARP spoofing are
also reduced.  This link-level protocol might be integrated with
Mobile-IP on links where increased security is needed, and is
complementary to IP Security (IPSEC) mechanisms. It is not intended
to function as a higher-level (mobile node as router) ad hoc routing
protocol, but might be integrated with such a protocol.}

