Router Behavior When Resolving a URL on the CLI

200-301 By islever Editorial Last updated

Explain the role of DHCP and DNS within the network

Short answer

D With default DNS lookup enabled, the router sends a query to its configured DNS server to resolve the entered URL to an IP address.

Question

What does a router do when it is configured with the default DNS lookup settings, and a URL is entered on the CLI?
  1. It continuously attempts to resolve the URL until the command is cancelled.
  2. It initiates a ping request to the URL.
  3. It prompts the user to specify the desired IP address.
  4. It attempts to query a DNS server on the network. Correct Answer

Key Takeaways

The router resolves names via DNS only when 'ip domain-lookup' is enabled and a name server is configured; otherwise the CLI treats the string as an invalid command.

When 'ip domain-lookup' is on (default) and a hostname/URL is typed at the CLI, the router treats it as a name to resolve and queries the DNS server configured with 'ip name-server'. If no server is set or resolution fails, it eventually times out.

Common mistake: Thinking the router pings (B) or prompts for an IP (C). It issues a DNS query; ping happens only after resolution, and no prompt appears.

Expert Analysis

Why the Answer Is Correct

D is correct. With default DNS settings ('ip domain-lookup' enabled), entering a URL at the CLI makes the router query its configured DNS server to translate the name into an IP address.

Why the Other Options Are Wrong

A is wrong: the router does not loop forever — a failed lookup times out. B is wrong: a ping is a separate action that occurs only after resolution. C is wrong: the CLI does not prompt for an IP; it either resolves or returns an error.

Community Comment Notes

The vote is D (100). Commenters note the router queries the DNS server from its DNS settings and retries or times out depending on configuration.

Official Reference

https://learningnetwork.cisco.com/s/ccna-exam-topics

This link opens the official vendor documentation in a new tab.

Community Votes

D
100%

100% of anonymous learners picked answer D. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 3 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 3

  1. Nethach 👍 3 Answered D
    I LOVE THIS QUESTION Translating "{typo}"...domain server (255.255.255.255)
  2. [Removed] 👍 2 Answered D
    D is correct The router will try to resolve the URL to an IP address by querying a DNS server configured in its DNS settings. If successful, it will use the resolved IP address for further processing. If unsuccessful, it may continue to retry or eventually timeout depending on the configured settings.
  3. 379c9f6 👍 4
    Good job to reach 1321.

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