Question

Difficulty: MediumNAT and PAT Implementation

A network administrator is configuring Network Address Translation (NAT) and Port Address Translation (PAT) on an edge router for an organization. The private internal network uses the 10.0.0.0/810.0.0.0/8 address space. The requirements state that hundreds of internal workstations must share a single registered public IPv4 address for outbound internet access, and external users must be able to securely access an internal HTTPS web server (10.0.0.5010.0.0.50) using that same public IP address. Which of the following implementation steps or mechanisms must be configured on the router to fulfill these requirements? (Select TWO.)

  1. Enable Port Address Translation (PAT / NAT Overload) to map multiple internal private IP addresses to the single public IP address using unique source port numbers.Answer
  2. B
    Configure a 1:1 Static NAT rule for all outbound client workstations to share the single public IP address without port mapping.
  3. Configure a static port forwarding (destination PAT) rule mapping inbound traffic aimed at public TCP port 443 to the internal IP address 10.0.0.50 on port 443.Answer
  4. D
    Configure Dynamic NAT with an ICMP pool mapping to translate inbound HTTPS server traffic across OSI Layer 3.

Answer

Port Address Translation (PAT / NAT Overload) must be configured for outbound host traffic using unique source port numbers, and a static port forwarding rule mapping public TCP port 443 to internal IP address 10.0.0.50:443 must be configured for inbound web traffic.
To satisfy both requirements using a single public IP address, the network administrator must implement PAT (NAT Overload) for outbound traffic, which uses unique source port numbers to track connections for multiple internal hosts. In addition, static port forwarding (destination PAT) must be configured to translate incoming requests targeting public TCP port 443 directly to the web server's internal address of 10.0.0.50 on port 443.

Step-by-Step Solution

1
Analyze outbound internet access requirements for multiple hosts.
Identified that hundreds of private hosts must share a single public IP address.
PAT (NAT Overload) uses unique Layer 4 source ports to multiplex outbound connections over a single public IPv4 address.
2
Analyze inbound external access requirements for the HTTPS web server.
Identified that external clients must reach 10.0.0.50 on TCP port 443 via the single public IP address.
Static port forwarding (destination PAT) maps incoming public IP traffic on TCP 443 to the specific internal server private IP and port.

Key Concept

NAT Overload (PAT) and Static Port Forwarding Implementation
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