3Rusty Russell, Linux netfilter Hacking HOW TO[EB/OL]. www. netfilter. org, 2002, 2.
4RONGFENG,DENG-GUO. A detailed implement and analysis of MPLS VPN based on IPSec proceedings of 2008 international con-ference on machine learning and cybernetics[R].2008.
5FRIEND. Robert making the gigabit IPSec VPN architecture secure source[J].{H}COMPUTER,2009.
6CHIUAN-HUNG LIN,YING-DAR LIN,YUAN-CHEN LAI. VPN gateways over network processors:impleme-ntation and eval-uation;real time and embedded technology and applications sympo-sium[A].
7ZHAO DA-YUAN,JIANG YI-XIN,LIN CHUANG. Imple-mentation and performance evaluation of IPSec VPN based on net-filter[J].{H}Journal of Wuhan University(Natural Science Edition),2009.