http://www.linuxforum.net/docnew/printthread.php?Cat=&Board=new&main=722&type=postiptables与stun Stun协议（Rfc3489、详见http://www.ietf.org/rfc/rfc3489.txt）将NAT粗略分为4种类型，即Full Cone、Restricted Cone、Port Restri

OUI:Organizationally Unique Identifiers 组织唯一标志符IAB:Individual Address Block  单独地址块ETH:ETHERTYPE    以太网类型 eth-eg: 0x809B AppleTalk协议  0x8137 IPX  0x86DD IPv6  0x0800 IPv4http://standards.ieee.org/regau