Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
Users on the inside network can browse the Internet through PAT, but an internal web server must now be reachable from outside on a predictable public IP. Which change best fits the 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
Add static NAT for the server and continue using PAT for user browsing.
This is correct because static NAT gives the server a stable public identity while PAT still serves outbound users.
B
Distractor review
Replace PAT entirely with DHCP relay.
This is wrong because DHCP relay is unrelated to Internet publishing of an internal server.
C
Distractor review
Disable NAT because the server already has a private address.
This is wrong because private IPv4 addresses are not Internet-routable.
D
Distractor review
Move the server into the native VLAN.
This is wrong because native VLAN assignment does not publish a server to the Internet.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is selecting DHCP relay or VLAN changes as solutions for making an internal server reachable from outside. DHCP relay only forwards DHCP requests across subnets and does not provide any public IP mapping or NAT functionality. Similarly, moving a server into the native VLAN does not affect its public IP address or NAT translation. Another common mistake is disabling NAT entirely, which breaks Internet connectivity because private IP addresses cannot be routed on the public Internet. Understanding that static NAT is required for predictable inbound access while PAT supports outbound user browsing is critical to avoid these traps.
Technical deep dive
How to think about this question
Network Address Translation (NAT) is a fundamental IP service that enables devices on a private network to communicate with external networks by translating private IP addresses to public IP addresses. PAT, a form of dynamic NAT, allows multiple internal hosts to share a single public IP address by using different source port numbers for each session. This is efficient for outbound traffic but does not provide a fixed public IP for inbound connections, which is necessary for hosting services like web servers. Static NAT differs by establishing a permanent one-to-one mapping between an internal private IP address and a public IP address. This ensures that external clients can reliably reach the internal server using a predictable public IP. In Cisco environments, static NAT is configured to maintain this stable mapping, while PAT continues to serve outbound user traffic. This design balances the need for many users to access the Internet with the requirement for a server to be reachable from outside. A common exam trap is confusing DHCP relay or VLAN assignments with NAT functionality. DHCP relay only forwards DHCP requests and does not affect NAT or Internet accessibility. Similarly, moving a server to the native VLAN does not influence its public IP mapping or NAT behavior. Disabling NAT altogether is incorrect because private IP addresses are not routable on the Internet, making static NAT essential for inbound access to internal servers.
KKey Concepts to Remember
- Network Address Translation (NAT) translates private IP addresses to public IP addresses to enable communication between internal hosts and the Internet.
- Port Address Translation (PAT) allows multiple internal hosts to share a single public IP address by differentiating sessions using unique source port numbers.
- Static NAT creates a one-to-one mapping between a private IP address and a public IP address, providing a stable public identity for internal servers.
- PAT is ideal for outbound traffic from many internal users but does not support predictable inbound access to internal servers from the Internet.
- Static NAT enables external clients to reach internal servers using a consistent public IP address, which is essential for hosting services like web servers.
- Disabling NAT on private IP addresses prevents Internet communication because private addresses are not routable on the public Internet.
- DHCP relay is used to forward DHCP requests across different subnets and does not affect NAT or Internet accessibility of internal servers.
- Assigning a server to a native VLAN does not influence its public accessibility or NAT behavior and is unrelated to Internet publishing.
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?
Network Address Translation (NAT) translates private IP addresses to public IP addresses to enable communication between internal hosts and the Internet.
What is the correct answer to this question?
The correct answer is: Add static NAT for the server and continue using PAT for user browsing. — The best change is to add a static NAT mapping for the internal web server while keeping PAT in place for ordinary users. In practical terms, PAT is excellent for many internal clients sharing one public address for outbound traffic, but it does not give an internal server the stable one-to-one public identity that outside clients expect for predictable inbound access. This is a standard NAT design distinction. User browsing and published server access are different requirements, and the best design often uses PAT for one and static NAT for the other.
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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