1.2 Routing concepts

Packet routing involves three main steps

1. Routing

Find the outgoing interface for the packet by looking for the longest match in the routing table.

show ip route x.x.x.x
show ip cef x.x.x.x

2. Switching

Move the packet between interfaces (process switching or cef switching)

show ip interface
show ip cef x.x.x.x detail

This step is where the load balancing happens

3. Encapsulation

Rebuild the packet’s layer 2 header (depends on the egress Interface).

! Ethernet
show ip arp 

! DMVPN
show ip nhrp