Cisco Certified Support Technician (CCST) NetworkingIP ConnectivityMedium
A network technician is configuring Network Address Translation (NAT) on a Cisco router. The requirement is to translate a single public IP address (203.0.113.10) to a single private IP address (192.168.1.5) for an internal server. Which command sequence would achieve this?
- Aip nat pool MYPOOL 203.0.113.10 203.0.113.10 netmask 255.255.255.252
- Bip nat inside source list 1 interface GigabitEthernet0/1 overload
- Cip nat outside source static 192.168.1.5 203.0.113.10
- Dip nat inside source static 192.168.1.5 203.0.113.10
Show answer & explanationAnswer & explanation
Correct answer: D. ip nat inside source static 192.168.1.5 203.0.113.10
The 'ip nat inside source static' command is used to create a one-to-one static NAT mapping between a private inside local IP address and a public inside global IP address, which is exactly what the scenario requires.
Why the other options are wrong
- A. This command defines a NAT pool, typically used for dynamic NAT, not a single static mapping for a server.
- B. This command is for PAT (NAT Overload) and uses an access list and an interface, not a specific static one-to-one mapping.
- C. The 'ip nat outside source static' command is used for outside-to-outside translation, which is not the requirement here.
Cisco IOS Static NAT Configuration
Configuring static NAT on a Cisco router involves using the 'ip nat inside source static' command to create a one-to-one mapping between private and public IP addresses.
- Requires defining inside and outside NAT interfaces.
- Command: `ip nat inside source static <local-ip> <global-ip>`.
- Enables external access to internal servers.
Memory trick: Inside Source Static is Simple and Sure for Servers.