I'd like to have some explanations about the handshake times. I used racoon to establish an IPsec SA between two computers on my LAN. The LAN latency time is about 0.110 ms and I measured the sending and receiving of packets with Ethereal. I did the test many times, always getting approximately the same values: Time Source Dest 0.00000 10.0.0.12 10.0.0.8 Identity Protection (Main Mode) 0.000919 10.0.0.8 10.0.0.12 Identity Protection (Main Mode) 0.063076 10.0.0.12 10.0.0.8 Identity Protection (Main Mode) 0.011600 10.0.0.8 10.0.0.12 Identity Protection (Main Mode) 0.038176 10.0.0.12 10.0.0.8 Identity Protection (Main Mode) 0.000239 10.0.0.8 10.0.0.12 Identity Protection (Main Mode) 0.000174 10.0.0.8 10.0.0.12 Informal 0.009175 10.0.0.12 10.0.0.8 Informal 1.100225 10.0.0.12 10.0.0.8 Quick Mode 0.012896 10.0.0.8 10.0.0.12 Quick Mode 0.006931 10.0.0.12 10.0.0.8 Quick Mode I always get a really high time value in the first message of quick mode exchange!!! It's 1 second!!! It's really a lot!!! I cannot figure out why!!! Can someone help me? The network latency time is low, it means that these time values are due to computation on the peers... which operation requires so much time? The first and second message should require the same computation on both peers as the operations are the same (in my case ESP tunnel mode negotiation, but the result doesn't change if I try ESP transport mode). Thanks, Giuseppe