Tài liệu IP Routing and NAT doc

IP ROUTING PROCESS Key Commands Shows and Debugs No ip route-cache (will show all packets in debug) Policy Routing: Access-list 1 permit 10.0.0.0 0.255.255.255 Route-map blah permit 10 Match ip address 1 Set default interface serial 0 Route-map blah permit 10 ! interface ethernet 0 ip address 20.1.1.1 255.255.255.0 ip policy route-map blah Show ip cache Debug ip routing Debug ip packet Show ip route 172.0.0.0 255.0.0.0 longer-prefix Additional Commands NAT: Ip nat pool ccie 10.1.1.1 10.1.1.254 netmask 255.255.255.0 ip nat inside source list 1 pool ccie interface ethernet 0 ip nat inside ip address 20.1.1.1 255.255.255.0 interface serial 0 ip nat outside ! access-list 1 permit 20.1.1.0 0.0.0.255 ! Or, Ip nat inside source list 1 interface s 0 overload Or Ip nat inside source list 1 pool ccie rotary Show ip nat translation Show ip nat statistics Clear ip nat trans * Debug ip nat Spot The Issue Notes In debug ip packet, if seeing "encapsulation failed" on frame, check frame map. If encapsulation failed on ethernet, no arp reply, so can't encaps into layer 3. Remember that loopback interfaces will show up as /32 routes in OSPF and EIGRP. Configure a summary address or range in order to reflect the proper subnet carried by the loopback interface. This is most important in LAT translation and NAT when a NAT address or LAT translation address calls for an address within the loopback's subnet. The remote router won't know about that address since only the /32 address of the loopback interface itself will be advertised. Same for PPP dialup routes apparently. . route-map blah Show ip cache Debug ip routing Debug ip packet Show ip route 172.0.0.0 255.0.0.0 longer-prefix Additional Commands NAT: Ip nat pool ccie 10.1.1.1. 0.0.0.255 ! Or, Ip nat inside source list 1 interface s 0 overload Or Ip nat inside source list 1 pool ccie rotary Show ip nat translation Show ip nat statistics