Implementing and Operating Cisco Enterprise Network Core Technologies (ENCOR) v1.2InfrastructureEasy
A network engineer is designing a new branch office network. Due to budget constraints, the branch will use a single internet connection, and all internal users need to access external resources. The design specifies that internal hosts use private IP addresses. Which network service must be configured on the branch router to allow these internal hosts to communicate with the internet?
- ADNS
- BDHCP
- CPTP
- DNAT
Show answer & explanationAnswer & explanation
Correct answer: D. NAT
Network Address Translation (NAT) is essential when internal hosts use private IP addresses and need to communicate with the internet, which uses public IP addresses. NAT translates the private IP addresses of internal hosts into one or more public IP addresses, allowing them to access external resources.
Why the other options are wrong
- A. DNS (Domain Name System) translates domain names to IP addresses, which is necessary for internet access but doesn't address the private-to-public IP translation.
- B. DHCP (Dynamic Host Configuration Protocol) assigns IP addresses to hosts, but doesn't handle the translation between private and public IP addresses.
- C. PTP (Precision Time Protocol) is for time synchronization and has no role in IP address translation for internet access.
Network Address Translation (NAT)
A method of remapping one IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic routing device.
- Translates private IP addresses to public IP addresses.
- Enables multiple devices to share a single public IP.
- Crucial for internet access from private networks.
- Provides a layer of security by hiding internal topology.
Memory trick: Internet: How local networks reach the world.