I have created a ESP tunnel using ip xfrm command between two linux machine such that if I ping from one machine to other then I am seeing ESP packets. Now what I am trying to do is that I have three machines, say MC1,MC2 and MC3 , There would be ESP tunnel only between MC1 and MC2 and MC1 can be connect to MC3 through MC2. So If I Ping from MC1 to MC3. there would be ESP Packet between MC1 and MC2 and ICMP packet between MC2 and MC3. How can I implement that? Any Help.