Question 1mediummulti select
Full question →mediummulti selectObjective-mapped
Exhibit
Current NAT: ip nat inside source list 10 interface GigabitEthernet0/0 overload
A branch office uses PAT overload on the edge router. Inside users can reach the internet, but return traffic for a newly deployed server must be mapped to a specific inside host. Which two statements are correct?
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
A static NAT entry can provide a consistent public-to-private mapping for the server
Static NAT is appropriate when inbound connections must always reach the same inside host.
B
Best answer
PAT overload is designed mainly for many-to-one outbound address sharing
PAT lets many inside devices share one outside address using ports.
C
Distractor review
Dynamic NAT always supports inbound access without additional configuration
Dynamic NAT does not guarantee a fixed outside address for inbound use.
D
Distractor review
NAT is unrelated to whether private addresses can reach the public internet
NAT/PAT is central to that common edge design.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is assuming that PAT overload can handle inbound connections to a specific inside host because it manages many-to-one address sharing. However, PAT overload dynamically assigns ports for outbound sessions and does not reserve a fixed public IP and port combination for inbound traffic. This misconception leads to incorrect answers suggesting dynamic NAT or PAT overload can support inbound server access without additional configuration. The key is recognizing that only static NAT provides a consistent public-to-private mapping necessary for inbound connectivity to a server.
Technical deep dive
How to think about this question
Network Address Translation (NAT) is a fundamental IP service that modifies IP address information in packet headers while in transit across a traffic routing device. PAT overload, a form of NAT, allows multiple inside hosts to share a single public IP address by using different port numbers, enabling efficient outbound internet access from private IP spaces. However, PAT overload does not provide a fixed mapping for inbound traffic, which is essential for servers that must be reachable from the internet. Static NAT creates a one-to-one mapping between a public IP address and a private IP address, ensuring consistent inbound and outbound communication for a specific host. This is critical for servers that require predictable access from external clients. Dynamic NAT assigns public IPs from a pool on a first-come, first-served basis but does not guarantee a fixed public IP for inbound connections, making it unsuitable for hosting public-facing services. A common exam trap is confusing PAT overload’s many-to-one outbound sharing capability with inbound accessibility requirements. While PAT overload efficiently supports multiple clients accessing the internet, it cannot provide the stable public-to-private IP mapping needed for inbound traffic to a server. Understanding this distinction helps avoid selecting dynamic NAT or ignoring the need for static NAT entries when inbound access is required.
KKey Concepts to Remember
- PAT overload allows multiple inside hosts to share a single public IP address by using unique port numbers for outbound traffic.
- Static NAT creates a one-to-one mapping between a public IP address and a private IP address, enabling consistent inbound and outbound communication.
- Dynamic NAT assigns public IP addresses from a pool on a first-come, first-served basis but does not guarantee fixed inbound access.
- PAT overload does not provide a fixed public IP and port mapping, making it unsuitable for hosting servers requiring inbound connectivity.
- Static NAT is necessary when inbound connections must always reach the same inside host, such as a public-facing server.
- NAT and PAT are essential for enabling private IP addresses to communicate with the public internet by translating address information.
- Inbound traffic to a server behind NAT requires static mappings to ensure predictable and reliable access from external clients.
- Dynamic NAT does not support inbound access without additional static configuration because it lacks fixed address mappings.
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?
PAT overload allows multiple inside hosts to share a single public IP address by using unique port numbers for outbound traffic.
What is the correct answer to this question?
The correct answer is: A static NAT entry can provide a consistent public-to-private mapping for the server — PAT overload is great for many inside clients sharing a public IP for outbound sessions. A public-facing server that needs predictable inbound reachability typically requires static NAT or static PAT.
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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