International Publisher for Advanced Scientific Journals (IPASJ)
L2TP/IPSec is a secure VPN which tunnels layer 2 packets. This protocol has been discussed and a solution has been proposed to create an L2TP/IPSec tunnel under FreeBSD. This paper discusses how mobility support is added to the L2TP/IPSec tunnel. The new solution tunnels Layer 2 packets without incurring tunnel-re-establishment at handoff, without losing packets during handoff, achieves better security than current mobility solutions for VPN, and supports fast handoff in IPv4 networks. First, a general framework of the mobility solution is introduced, followed by details of the eight modifications required to achieve a fully working system. Finally, the analysis and discussion on the security and the performance of the new solution are provided.