Question 735 of 2,152
NAT and PATmediumMultiple ChoiceObjective-mapped

How to Configure Dynamic NAT (Without PAT) for One-to-One Translation

This 300-410 practice question tests your understanding of nat and pat. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.

Given this partial configuration:

ip nat pool MYPOOL 203.0.113.10 203.0.113.20 netmask 255.255.255.0
ip nat inside source list 1 pool MYPOOL
access-list 1 permit 192.168.1.0 0.0.0.255

What is the effect?

Quick Answer

The answer is that inside hosts are dynamically mapped one-to-one to a pool address, and if the pool is exhausted, new translations fail. This is the effect of dynamic NAT without overload, also known as dynamic one-to-one translation, where the `ip nat inside source list 1 pool MYPOOL` command binds each inside host to a unique public address from the pool without port address translation (PAT). On the Cisco CCNP ENARSI 300-410 exam, this configuration tests your understanding of how dynamic NAT differs from PAT—a common trap is assuming overload is enabled by default, but here the absence of the `overload` keyword means no port multiplexing occurs. When the pool of five addresses (203.0.113.10 through 203.0.113.20) is fully allocated, any additional inside host attempting outbound communication will simply fail to translate. Memory tip: think “no overload, no sharing”—each inside host gets its own public IP, and once the pool is empty, new connections are dropped.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

Inside hosts are dynamically mapped to a pool address; if the pool is exhausted, new translations fail.

The configuration uses a standard ACL to match inside hosts (192.168.1.0/24) and dynamically assigns them a unique address from the pool 203.0.113.10–203.0.113.20. Because no 'overload' keyword is present, PAT is not enabled; each translation consumes a pool address, and once all 11 addresses are used, new translations fail until an existing translation times out or is cleared.

Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • Inside hosts are translated to addresses in the pool using PAT.

    Why it's wrong here

    No 'overload' keyword means no port multiplexing; it's one-to-one dynamic NAT.

  • Inside hosts are dynamically mapped to a pool address; if the pool is exhausted, new translations fail.

    Why this is correct

    Without overload, each translation consumes one pool address; exhaustion blocks new flows.

    Related concept

    Read the scenario before looking for a memorised answer.

  • The router uses the pool address as the source for all outbound traffic, regardless of ACL.

    Why it's wrong here

    The ACL restricts which inside addresses are eligible for translation.

  • This configuration requires the 'ip nat outside' interface command to function.

    Why it's wrong here

    While 'ip nat outside' is needed on the outside interface, the question asks about the effect of the given commands alone; the effect is dynamic NAT without overload.

Common exam traps

Common exam trap: answer the scenario, not the keyword

Cisco often tests the distinction between dynamic NAT and PAT by omitting the 'overload' keyword, leading candidates to assume PAT is always used with a pool when in fact it must be explicitly configured.

Trap categories for this question

  • Keyword trap

    No 'overload' keyword means no port multiplexing; it's one-to-one dynamic NAT.

  • Command / output trap

    While 'ip nat outside' is needed on the outside interface, the question asks about the effect of the given commands alone; the effect is dynamic NAT without overload.

Detailed technical explanation

How to think about this question

Dynamic NAT without overload uses a one-to-one mapping between inside local and inside global addresses; the router creates a translation entry when the first packet from an inside host traverses the NAT router, and the pool address is released only after the translation idle timeout (default 24 hours for TCP/UDP, or configurable via 'ip nat translation timeout'). In a real-world scenario, if 12 hosts attempt outbound connections simultaneously, the 12th will fail with 'NAT: translation failed (pool exhausted)' until a previous translation expires or is cleared manually.

KKey Concepts to Remember

  • Read the scenario before looking for a memorised answer.
  • Find the constraint that changes the correct option.
  • Eliminate answers that are true in general but not in this case.

TExam Day Tips

  • Watch for words such as best, first, most likely and least administrative effort.
  • Review why wrong options are wrong, not only why the correct option is correct.

Key takeaway

Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

Real-world example

How this comes up in practice

A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.

Visual reference

Inside (Private) PC-A 10.0.0.1 PC-B 10.0.0.2 NAT Router Outside (Public) 203.0.113.1 Inside Global Server PAT: many private IPs share one public IP via unique port numbers

What to study next

Got this wrong? Here's your next step.

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

Related practice questions

Related 300-410 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Practice this exam

Start a free 300-410 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

FAQ

Questions learners often ask

What does this 300-410 question test?

NAT and PAT — This question tests NAT and PAT — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Inside hosts are dynamically mapped to a pool address; if the pool is exhausted, new translations fail. — The configuration uses a standard ACL to match inside hosts (192.168.1.0/24) and dynamically assigns them a unique address from the pool 203.0.113.10–203.0.113.20. Because no 'overload' keyword is present, PAT is not enabled; each translation consumes a pool address, and once all 11 addresses are used, new translations fail until an existing translation times out or is cleared.

What should I do if I get this 300-410 question wrong?

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

About these practice questions

Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →

How Courseiva writes practice questions · Editorial policy

Keep practising

More 300-410 practice questions

Last reviewed: Jul 4, 2026

Question Discussion

Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.

Loading comments…

Sign in to join the discussion.

This 300-410 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 300-410 exam.