Question 1mediummultiple choice
Full question →mediummultiple choiceObjective-mapped
A user reports they can access internal servers and the default gateway but cannot reach external websites. The technician checks the router's ACL and finds a rule that permits all outbound traffic. What is the most likely cause?
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
Distractor review
DNS resolution failure
DNS failure would prevent resolving hostnames, but the user could still access external websites by IP address. The scenario describes general external access failure, not just name resolution.
B
Distractor review
Incorrect default gateway
If the default gateway were incorrect, the user would not be able to access the default gateway itself, nor internal servers on different subnets. The user can access internal servers, so the gateway is correct.
C
Best answer
NAT configuration issue
NAT is required to translate private addresses to a public address for internet access. If NAT is not configured or malfunctioning, outbound traffic will not reach the internet even if the ACL permits it.
D
Distractor review
Proxy server misconfiguration
A misconfigured proxy could block internet access, but the question states the ACL permits all outbound traffic. Proxy issues are possible but less likely than NAT, and the scenario does not mention proxy settings.
Common exam trap
Common exam trap: NAT rules depend on direction and matching traffic
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Technical deep dive
How to think about this question
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
KKey Concepts to Remember
- Static NAT maps one inside address to one outside address.
- PAT allows many inside hosts to share one public address using ports.
- Inside local and inside global describe the private and translated addresses.
- NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
- Identify inside and outside interfaces first.
- Check whether the scenario needs static NAT, dynamic NAT or PAT.
- Do not confuse NAT matching ACLs with normal packet-filtering intent.
Related practice questions
Related N10-009 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Network+ network fundamentals practice questions
Practise N10-009 questions linked to Network+ network fundamentals.
Network+ implementation practice questions
Practise N10-009 questions linked to Network+ implementation.
Network+ operations practice questions
Practise N10-009 questions linked to Network+ operations.
Network+ security practice questions
Practise N10-009 questions linked to Network+ security.
Network+ troubleshooting practice questions
Practise N10-009 questions linked to Network+ troubleshooting.
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 network engineer needs to connect two switches located 400 meters apart. The cable run includes high electromagnetic interference from nearby machinery. The engineer decides to use fiber optic cabling. Which transceiver type and fiber combination should be used to ensure the link reaches 400 meters while remaining cost-effective?
Question 2
A network engineer is designing a new switched network and needs to ensure that broadcast traffic from one department does not reach another department's workstations. The engineer plans to use VLANs. Which of the following must be configured on the switches to isolate broadcast domains as intended?
Question 3
A security engineer is configuring a site-to-site VPN between two branch offices. The requirement is to encrypt all traffic between the two networks using IPsec. Which IPsec mode should be used to encrypt the entire IP packet including the original header?
Question 4
A network administrator is connecting two switches to increase bandwidth and provide redundancy. Which technology should be used to combine multiple physical links into a single logical link?
Question 5
A network administrator is experiencing issues where unauthorized devices are offering IP addresses to clients, causing connectivity problems. Which security feature should be enabled on switches to prevent this?
Question 6
A network administrator is troubleshooting a connectivity issue and suspects the problem is related to the physical cabling. At which layer of the OSI model should the administrator begin their investigation?
FAQ
Questions learners often ask
What does this N10-009 question test?
Static NAT maps one inside address to one outside address.
What is the correct answer to this question?
The correct answer is: NAT configuration issue — If the ACL allows all outbound traffic but external access fails, the issue is likely with NAT. The router must translate private IP addresses to a public IP for internet access. If NAT is not configured or misconfigured, traffic cannot reach external networks. DNS resolution would affect name resolution but the user might be using IP addresses; however, the scenario implies general internet access failure. Incorrect default gateway would prevent internal access, which works. Proxy misconfiguration could interfere but NAT is a more common cause when internal works and external fails.
What should I do if I get this N10-009 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
Discussion
Loading comments…
Sign in to join the discussion.