Examkin

Soru

Zorluk: ZorNAT and PAT Implementation

An enterprise network administrator deploys a new segment of 250 internal workstations that require simultaneous outbound internet access. The edge firewall is configured with dynamic NAT using a public IP pool consisting of a single /28/28 prefix (14 usable public IPv4 addresses). During peak operational hours, only the first 14 hosts can establish outbound sessions, while all remaining workstations experience connection timeouts when reaching external web servers. Which of the following configuration modifications will resolve the connectivity issue without acquiring additional public IP addresses?

  1. Reconfigure the network address translation policy to enable overload (PAT) on the dynamic IP pool.Cevap
  2. B
    Change the NAT configuration to 1:1 Static NAT assignments for each workstation using the existing public IP pool.
  3. C
    Force all outbound session translations on the firewall to use UDP transport ports instead of TCP ports.
  4. D
    Reconfigure the internal workstation network adapters to encapsulate outbound traffic strictly at Layer 2 to bypass firewall translation.

Cevap

Reconfiguring the network address translation policy to enable overload (PAT) on the existing pool will allow up to thousands of concurrent outbound connections across the available public addresses.
Standard Dynamic NAT maps internal private IP addresses to external public IP addresses on a one-to-one basis without modifying Layer 4 port numbers. Because the pool contains only 14 public IP addresses (/28/28 prefix has 16 addresses minus network and broadcast), only 14 hosts can communicate externally at any given time. Enabling Port Address Translation (PAT / NAT Overload) allows the firewall to map multiple internal private IP addresses to a single public IP address by assigning a unique ephemeral source port number to each outbound session, enabling all 250 hosts to communicate simultaneously over the existing pool.

Adım Adım Çözüm

1
Analyze the reported symptom and environment constraints.
Dynamic NAT without port mapping (1:1 dynamic binding) limits concurrent external sessions strictly to the number of available public IP addresses (14 addresses for 250 hosts).
Once all 14 public pool addresses are assigned to active host connections, the pool is exhausted and subsequent translation requests are dropped.
2
Evaluate the technical requirement.
All 250 internal hosts need outbound access simultaneously without purchasing additional public IPv4 space.
Port Address Translation (PAT / Overload) tracks outbound traffic streams using source port numbers in addition to IP addresses, allowing thousands of sessions to share a single public IP address.
3
Select the appropriate NAT implementation strategy.
Enabling PAT (NAT overload) on the existing pool configuration resolves the session exhaustion issue.
PAT scales concurrent connectivity exponentially by multiplexing Layer 4 port numbers.

Anahtar Kavram

Port Address Translation (PAT / Overload) vs Dynamic NAT Pool Exhaustion
Bu soruyu puanla

Konular

NAT and PAT Implementation

Bu konudan daha fazla soru