\abstract{
Recently the Layer 2 802.11 link-layer security mechanism called
WEP has been shown to be flawed.  In this paper we present a combined
layer 3 Mobile-IP and IPSEC architecture that we believe is superior
to layer 2 mechanisms like WEP.  We overview possible routing
security technologies and then present two possible integrated
IPv4 Mobile-IP/IPSEC routing daemon architectures that we refer to
as "closely-coupled" and "loosely-coupled".  The older closely-coupled
architecture relies on a direct binding of IPSEC policy attributes
to routing table entries by Mobile-IP routing daemons.
The current architecture is based on a more traditional
loosely-coupled association between the current FreeBSD IPSEC
implementation (called KAME) and the PSU Mobile-IP daemons.
Our discussion concludes with an architectural analysis of combined
Mobile-IP/IPSEC and a call for the use of IPSEC as part of any
mobile VPN scheme.
}

