If you can successfully ping a remote computer by its IP address but not by its hostname, which network service is most likely experiencing a problem?

Introduction / Context:
This troubleshooting question focuses on distinguishing between connectivity problems and name resolution problems in a TCP/IP network. Being able to reach a host by IP address but not by hostname is a classic symptom that points to a very specific layer and service in the network stack.

Given Data / Assumptions:
- Pinging the remote host using its IP address works, so basic IP connectivity is fine.
- Pinging the same host using a hostname or fully qualified domain name fails.
- No information suggests general packet loss or routing problems.
- We must identify which network service is most likely at fault in this scenario.

Concept / Approach:
When ping by IP succeeds, it proves that routing, switching, and the remote host's IP configuration are functional. The failure of ping by name indicates that the client cannot translate the hostname into the correct IP address. This translation is performed by Domain Name System. Therefore, a misconfigured DNS server, incorrect DNS client settings, or missing DNS records are the most likely causes.

Step-by-Step Solution:
Step 1: Interpret the successful ping by IP as evidence that the underlying network path is working.Step 2: Interpret the failed ping by hostname as evidence of name resolution failure rather than connectivity failure.Step 3: Recall that DNS is the standard service responsible for resolving hostnames to IP addresses.Step 4: Consider that ARP resolves IP to MAC addresses on the local link, which must already be working if ping by IP is successful.Step 5: Conclude that DNS is the most likely service experiencing a problem.

Verification / Alternative check:
In real troubleshooting, you can verify this diagnosis by running a command such as nslookup or dig on the hostname. If these commands fail or return incorrect IP addresses, it confirms a DNS issue. You can also check the DNS server settings in the client configuration or temporarily add an entry to the local hosts file to see whether name resolution succeeds without DNS.

Why Other Options Are Wrong:
DHCP provides IP configuration to clients. If DHCP were failing, the client might not have a valid IP address at all, but it would not selectively break only name based pings. ARP operates at the local link level and must be functioning if ping by IP is working. ICMP provides echo requests and replies, and its operation is proven by the successful IP based ping. NTP synchronizes time and is unrelated to IP versus name reachability.

Common Pitfalls:
One common pitfall is to assume a routing problem whenever any network request fails. Another is to overlook DNS misconfigurations such as wrong server address, missing DNS suffix, or stale records. Remember that the distinction between IP based and name based connectivity is a strong clue pointing directly to DNS, which speeds up root cause analysis.

Final Answer:
If you can ping by IP but not by name, the most likely problem is with the DNS service or configuration.