Cisco IOS NAT and PAT: Static, Dynamic, and Overload Configuration
Working reference for the four NAT modes on Cisco IOS. The inside-local / inside-global / outside-global vocabulary that confuses everyone the first time, the ip nat inside / ip nat outside interface markings (most common cause of broken NAT), Static NAT with full IP and port-specific variants, Dynamic NAT with a public pool, PAT (overload) with the WAN interface IP and with a pool, the show ip nat translations and statistics commands, clear ip nat translation, and the pitfalls (missing markers, ACL gaps, PAT port exhaustion, NAT/IPsec interaction).