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 interf
Trang 1IP ROUTING PROCESS
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
Ị
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
io nat inside
ip address 20.1.1.1 255.255.255.0
interface serial 0
ip nat outside
Ị
access-list 1 permit 20.1.1.0 0.0.0.255
Ị
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
In debug ip packet, if seeing "encapsulation
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
suonet 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
Notes