Firstly, a general picture of IPSec is introduced and the incompatibility between IPSec and NAT/NAPT is analyzed in detail in this paper.

• 本文首先介绍了IPSec协议的基本体系和应用情况，通过试验引出了IPSec和NAT/NAPT之间的不兼容问题，并对其原因进行了详尽的分析。