[strongSwan] Avoid leakage of packets addressed to/from private IP space

[Vitaly Repin]

Hello,

I've recently faced an issue with package leakage from the clients
connected through IPSEC. (The packages addressed to VPN address space
were "leaking" through external interface).

The problem is now solved and I've documented complete solution here:
http://vrepin.org/vr/IPsec-PacketLeakage/

I hope it can be useful for other strongwan users.

-- 
WBR & WBW, Vitaly