Question

Difficulty: MediumUtilizing Command-Line Network Troubleshooting Utilities

A network technician is troubleshooting a client workstation that cannot access an internal web portal by its fully qualified domain name (FQDN). Following a standard bottom-up troubleshooting workflow to isolate network issues from local network configuration to name resolution, place the following command-line steps in the correct logical diagnostic sequence.

  1. 1Run ipconfig /all to verify the client machine's local IP address, subnet mask, default gateway, and primary DNS server configuration.
  2. 2Run ping 192.168.1.1 to confirm Layer 3 network connectivity from the client to its local default gateway.
  3. 3Run ping 10.0.5.25 to verify ICMP reachability directly to the target web server's IP address, bypassing DNS.
  4. 4Run nslookup portal.lab.internal to test whether the configured DNS server correctly resolves the host name to an IP address.

Answer

The correct sequence begins with checking local interface settings using ipconfig /all, testing local subnet routing using ping to the default gateway, testing remote host IP reachability using ping to the target IP, and finally diagnosing DNS name resolution using nslookup.
The logical sequence follows standard CompTIA network troubleshooting: first, check local host configuration using ipconfig /all; second, verify local subnet network reachability by pinging the default gateway IP; third, verify end-to-end network path reachability by pinging the destination server's IP address directly; fourth, test domain name lookup functionality using nslookup to confirm FQDN-to-IP mapping.

Step-by-Step Solution

1
Inspect local network configuration
The technician verifies the local IP parameters (IP address, subnet mask, default gateway, DNS server) using ipconfig /all.
This confirms basic NIC operational status and verifies assigned IP configuration settings.
2
Test local router reachability
The technician issues ping 192.168.1.1 to test connectivity to the local gateway router.
Pinging the default gateway confirms local link layer and Layer 3 subnet connectivity.
3
Test end-to-end IP routing reachability
The technician executes ping 10.0.5.25 using the target server's raw IP address.
Directly pinging the destination IP tests end-to-end routing without relying on domain name resolution.
4
Diagnose host name resolution
The technician uses nslookup portal.lab.internal to evaluate FQDN query responses from the DNS server.
Performing an explicit DNS lookup isolates application layer name resolution problems after IP reachability is confirmed.

Key Concept

Command-Line Troubleshooting Methodology & Tool Selection
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