An outside local address identifies an outside host from the perspective of the inside network. In NAT terminology, it is the outside host’s address before any destination translation. section 9.2.2 section 9.4
Interpret the address through the router’s perspective:
- Treat hosts reached through the router’s external interface as outside hosts; their address as seen by the inside network is outside local. section 9.2.2
- Distinguish outside local from outside global: outside local is the inside network’s view, while outside global is the outside network’s view. section 9.4
- Expect both addresses to be identical when the router performs no destination NAT. section 9.4
R1 reaching 8.8.8.8
With R1 G0/0 connected to the inside network and G0/1 connected to the internet, PC1 sees 8.8.8.8 as an outside host. The address of that host from PC1’s network perspective is the outside local address. section 9.2.2
