URPF

泰克实验室塑造

URPF:
Loose MODE: 只要FIB中有该SrcAddr，不管是从哪个接口学到都可。
Strict MODE：不仅要查SrcAddr，而且还要看是否来自从该接口学到的源地址。
r1(config-if)#ip verify unicast source reachable-via ?
  any  Source is reachable via any interface   //loose mode
  rx   Source is reachable via interface on which packet was received  //strict mode
Strict mode
In strict mode each incoming packet is tested against the FIB and if the interface is not the best reverse path the packet check will fail. By default failed packets are discarded. //从FIB表中查,不是最优的路径学到,则丢掉.FIB是转发信息数据库=cef表
Loose mode
In loose mode each incoming packet's source address is also tested against the FIB and if the source address is not reachable via an interface the packet check will fail. //不能通过某一个接口学到,则丢掉

phil

Thanks for your information.