< >; IP: tunneling
< >; IP: GRE tunnels over IP
[ ] IP: ARP daemon support (EXPERIMENTAL)
[*] IP: TCP syncookie support (disabled per default) 能防DOS攻击,但会降低一点性能,总的说性价比不错
< >; IP: AH transformation
< >; IP: ESP transformation
< >; IP: IPComp transformation
< >; IP: tunnel transformation
