CCNA Foundations: Static NAT — One-to-One Inside/Outside Mapping

Archive lab

Deploy a single-edge router performing static one-to-one NAT so an inside host has a fixed public address. You will mark inside/outside interfaces, create the static NAT mapping, and verify reachability to an internet host and the translation table. The lab is intentionally small but enterprise-clean, with a routed inside transit, an access switch for the user LAN, and an external host representing the internet.

Learning objectives

• Identify and mark NAT inside and outside interfaces on an edge router
• Configure a one-to-one static NAT mapping for a specific inside host
• Verify NAT operation using translation tables and end-to-end tests from hosts
• Apply static routing to ensure return reachability for NATed flows

Troubleshooting focus

• If CLIENT10 cannot reach the outside host: Verify CLIENT10 IP and default gateway (10.10.10.10/24 via 10.10.10.1) and that RTR-DIST has a default route to RTR-EDGE.; On RTR-EDGE, ensure the internal transit interface is marked as NAT inside and the public interface as NAT outside.; Confirm the static mapping pairs 10.10.10.10 with 203.0.113.3 exactly.; Run show ip nat translations and initiate fresh pings to watch for entries.
• If the outside host cannot reach the inside-global 203.0.113.3: Ensure INTERNET-HOST’s default route points to 203.0.113.1 and that it can ARP for 203.0.113.3 (the edge should respond).; Confirm RTR-EDGE still has a route to 10.10.10.0/24 via 10.0.12.1 so post-NAT traffic forwards internally.
• If translations appear but traffic still fails: check interface status (up/up), masks, and that you didn’t mix up the /29 and /30 subnets.