CompTIA Server+ (SK0-005)TroubleshootingMedium
A server administrator is investigating a server that is experiencing intermittent network connectivity issues, characterized by dropped packets and unusually high latency to external resources. Internal network communication (within the same subnet) is unaffected. What is the MOST likely cause?
- AA saturated internal network switch.
- BIncorrect subnet mask on the server.
- CA faulty NIC on the server.
- DA misconfigured default gateway on the server.
Show answer & explanationAnswer & explanation
Correct answer: D. A misconfigured default gateway on the server.
If internal network communication (within the same subnet) is fine, but external communication (to different subnets/internet) is intermittently affected, it strongly points to an issue with the default gateway. The default gateway is responsible for routing traffic outside the local subnet. Intermittent issues suggest either a flapping gateway, an overloaded gateway, or incorrect configuration that sporadically routes traffic to a black hole.
Why the other options are wrong
- A. A saturated internal switch would impact all traffic passing through it, including internal communication within the same subnet.
- B. An incorrect subnet mask would prevent communication even within the local subnet by misidentifying local vs. remote hosts.
- C. A faulty NIC would affect all network communication, internal and external.
Default Gateway Misconfiguration
Incorrectly configured default gateway IP address on a server, preventing or intermittently disrupting communication with hosts outside its local subnet.
- Symptoms include successful internal network communication but failed or intermittent external communication.
- The default gateway is the exit point for traffic leaving the local network segment.
- Troubleshooting involves checking `ipconfig` (Windows) or `ip route` (Linux) and pinging the gateway IP.
Memory trick: Gateway is the 'Exit Door' to the world!