You have a web server with a private IP address within your network. You want users from the internet to access it. Which type of NAT do you use?
- DHCP
- static NAT
- dynamic NAT
- PAT
Explanation: Static NAT is the correct choice for this scenario because it provides a one-to-one mapping between a specific private (inside local) IPv4 address and a public (inside global) IPv4 address.
Key reasons for using static NAT for a web server include:
- External Initiation: Unlike dynamic NAT or PAT, which are primarily designed for internal hosts reaching out to the internet, static NAT specifically allows external devices to initiate connections to internal devices.
- Persistent Mapping: Static translations are permanent and continuously remain in the translation table, regardless of whether they are actively being used. This ensures that the web server is always reachable at the same public IP address.
- Specific Use Case: The source material explicitly states that static NAT is used when a company has a server that needs to be accessible from outside the network, citing a web server as a primary example.
In contrast, dynamic NAT and PAT are typically used to allow internal users to share public addresses when accessing the internet, and they do not inherently provide the permanent, externally-reachable entry required for a public-facing server. DHCP is used for assigning addresses to hosts, not for translating them for internet access.
Related exam: Modules 8 – 13: Checkpoint Exam: Network Routing Answers (CCNP ENCOR v9)
