Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A company wants an internal web server to be reachable consistently from the Internet using one known public IPv4 address. Which NAT approach best fits that requirement?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Best answer
Static NAT
This is correct because static NAT gives the server a permanent public mapping.
B
Distractor review
PAT overload
This is wrong because PAT is mainly used for many outbound users sharing fewer public addresses.
C
Distractor review
No NAT, because private IPv4 addresses are publicly routable
This is wrong because private IPv4 addresses are not routable on the public Internet.
D
Distractor review
DHCP relay
This is wrong because DHCP relay is unrelated to public reachability of an internal server.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is selecting PAT overload as the solution for making an internal server reachable from the Internet. PAT is primarily designed for outbound traffic from multiple internal hosts sharing a single public IP, not for inbound access to a specific server. Another trap is thinking private IPv4 addresses are publicly routable, which they are not, so no NAT would fail to provide Internet reachability. Also, confusing DHCP relay with NAT functions can mislead candidates, as DHCP relay only forwards DHCP messages and does not affect public IP mappings or server accessibility from the Internet.
Technical deep dive
How to think about this question
Network Address Translation (NAT) is a fundamental IP Services technology that modifies IP address information in packet headers while in transit across a routing device. Static NAT specifically maps one private IPv4 address to one public IPv4 address permanently, enabling consistent inbound and outbound communication. This is essential for hosting internal servers that must be reachable from the Internet using a fixed public IP address. When a company wants an internal web server accessible from the Internet, static NAT is the preferred method because it provides a one-to-one mapping between the internal private IP and a public IP address. This ensures external clients always reach the same public IP, which translates to the internal server's private IP. Unlike PAT (Port Address Translation), which multiplexes many private IPs to a single public IP using different ports, static NAT guarantees a stable, predictable address for inbound connections. A common exam trap is confusing static NAT with PAT overload or assuming private IP addresses can be routed on the public Internet. Static NAT is necessary for inbound access to internal servers, while PAT is designed for outbound traffic from multiple hosts sharing fewer public IPs. Additionally, DHCP relay is unrelated to NAT and public reachability, as it only forwards DHCP requests across subnets. Understanding these distinctions is critical for correctly answering NAT-related questions on the CCNA exam.
KKey Concepts to Remember
- Static NAT creates a permanent one-to-one mapping between a private IPv4 address and a public IPv4 address for consistent inbound and outbound communication.
- PAT overload allows multiple private IP addresses to share a single public IP address by using different port numbers, primarily for outbound traffic.
- Private IPv4 addresses are not routable on the public Internet and require NAT to enable Internet connectivity.
- Static NAT is essential for hosting internal servers that must be reachable from the Internet using a fixed public IP address.
- DHCP relay forwards DHCP requests between clients and servers across different subnets but does not affect NAT or public IP address mappings.
- PAT is unsuitable for inbound connections to internal servers because it does not provide a fixed public IP mapping.
- Static NAT ensures external clients can reliably reach an internal server using a known public IP address.
- Confusing static NAT with PAT or assuming private IPs are publicly routable leads to incorrect NAT configurations and exam mistakes.
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.
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More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A router learns the same prefix from both OSPF and EIGRP. Which route is installed by default?
Question 2
A router shows this output: R1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/DR 00:00:34 192.168.12.2 GigabitEthernet0/0 10.1.1.3 1 2WAY/DROTHER 00:00:39 192.168.12.3 GigabitEthernet0/0 Which statement is correct?
Question 3
What is the OSPF metric called?
Question 4
A non-root switch has two uplinks toward the root bridge. One path has a lower total STP cost than the other. What role will the lower-cost uplink have?
Question 5
A router interface applies this ACL inbound: 10 deny tcp any any eq 80 20 permit ip any any A user reports that web browsing to a server by IP address fails, but ping works. Which statement best explains the behavior?
Question 6
A router learns route 198.51.100.0/24 from OSPF with AD 110 and also has a static route to the same prefix configured with AD 150. Which route is installed?
FAQ
Questions learners often ask
What does this 200-301 question test?
Static NAT creates a permanent one-to-one mapping between a private IPv4 address and a public IPv4 address for consistent inbound and outbound communication.
What is the correct answer to this question?
The correct answer is: Static NAT — Static NAT is the best fit because it creates a fixed one-to-one relationship between the inside server and the public address. In practical terms, outside clients need a stable public identity for the server. They cannot rely on a translated address that changes session by session. Static NAT gives that predictability. This is different from PAT, which is designed for many inside users sharing fewer public addresses for outbound traffic. The question is about publishing a server, not conserving addresses for client browsing. That is why static NAT is the strongest answer.
What should I do if I get this 200-301 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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