Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A host has a valid IP address and subnet mask from DHCP but cannot reach remote networks because no gateway was provided. What is the best explanation?
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
The host has no next-hop gateway for traffic destined outside its local subnet.
This is correct because a default gateway is needed for off-subnet traffic.
B
Distractor review
The host cannot use ARP on the local network anymore.
This is wrong because lack of a gateway does not prevent local ARP use.
C
Distractor review
The host automatically becomes part of every remote subnet.
This is wrong because gateway absence does not expand the local subnet.
D
Distractor review
The host must convert its access port into a trunk.
This is wrong because switchport trunking is unrelated to a missing gateway option.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A common exam trap is assuming that a host without a default gateway cannot communicate at all. Many candidates mistakenly believe that missing a gateway disables all network communication, but in reality, the host can still communicate with devices on its local subnet using ARP. The trap lies in confusing local subnet communication with remote network access. The question specifically tests understanding that the lack of a gateway prevents forwarding to remote networks, not local connectivity. Misreading this can lead to selecting incorrect options that focus on ARP or subnet expansion rather than the gateway role.
Technical deep dive
How to think about this question
A host configured with an IP address and subnet mask understands which IP addresses belong to its local subnet and which do not. To communicate with devices outside its local subnet, the host must forward packets to a next-hop device, typically a default gateway, which routes traffic to remote networks. Without a default gateway, the host cannot send packets beyond its local subnet, even if it has a valid IP configuration. The default gateway is a critical part of IP services and routing on a host. DHCP servers commonly provide the default gateway address along with the IP address and subnet mask. If the DHCP server fails to supply a gateway, the host lacks the necessary routing information to forward off-subnet traffic, causing communication failures with remote networks. This behavior is fundamental in Cisco networking and is tested in the CCNA exam to confirm understanding of host routing basics. A common exam trap is to confuse local network communication issues with gateway problems. The host can still communicate with devices on the same subnet using ARP and direct Layer 2 forwarding, but it cannot reach remote networks without a gateway. Practically, this means devices appear reachable locally but unreachable remotely, which is a key troubleshooting clue in Cisco environments.
KKey Concepts to Remember
- A host uses its subnet mask to determine whether a destination IP address is local or remote and decides how to forward packets accordingly.
- A default gateway provides the next-hop IP address for traffic destined outside the host's local subnet, enabling remote network communication.
- DHCP servers typically assign the IP address, subnet mask, and default gateway to hosts to automate network configuration.
- Without a default gateway, a host cannot forward packets to remote networks, even if it has a valid IP address and subnet mask.
- Local communication on the same subnet uses ARP to resolve MAC addresses and does not require a default gateway.
- The absence of a default gateway does not affect the host's ability to communicate within its local subnet.
- Hosts rely on the default gateway to route traffic to other subnets, making gateway configuration essential for inter-network connectivity.
- Troubleshooting unreachable remote networks should include verifying the presence and correctness of the default gateway setting on the host.
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.
Related practice questions
Related 200-301 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
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CCNA IPv6 practice questions
Practise IPv6 addressing, routes, neighbour discovery and common IPv6 exam traps.
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?
A host uses its subnet mask to determine whether a destination IP address is local or remote and decides how to forward packets accordingly.
What is the correct answer to this question?
The correct answer is: The host has no next-hop gateway for traffic destined outside its local subnet. — The best explanation is that the host has no next-hop path for off-subnet traffic. In plain language, the device knows what its own local network looks like, but it does not know where to send packets when the destination is outside that local range. Without a default gateway, remote communication usually fails even though local communication can still work. This is a core host-configuration concept. The correct answer is the one focused on the absence of a next hop for remote destinations.
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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