Hi list, I does not found anything reliable while googling and so I'll ask you. Assuming you've IPSec-VPN gateways that are behind NATing routers (which are not yours) you'll need a NAT Traversal patch for free/SWan IPSec to tunnel the VPN traffic, cause the NAT modifies the packets and unpatched free/SWan won't work than properly. --------------- ----------------- | VPN Gateway |--| NATing Router |--- Internet ---| --------------- ----------------- I N E --------------- ----------------- T | VPN Gateway |--| NATing Router |--- Internet ---| --------------- ----------------- ASC-II art - is'nt it :O? Does the new implementation of IPSec in kernel >=2.5.45 include such mechanism or do i have to patch thoose kernels too? Thx in advance Michael