NE NE Network Troubleshooting

Question 1

What is the correct order of the OSI model troubleshooting approach when using a bottom-up method?

Accepted Answer

Physical → Data Link → Network → Transport → Application

Answer

Bottom-up troubleshooting starts at Layer 1 (Physical) and works up, verifying each layer before moving to the next, ensuring foundational issues are not missed.

Question 2

Which command verifies end-to-end IP reachability between two hosts?

Accepted Answer

ping

Answer

Ping sends ICMP Echo Request packets to a destination and reports whether responses are received, confirming IP-layer reachability.

Question 3

What does a high number of CRC errors on a switch interface typically indicate?

Accepted Answer

Physical layer issues such as bad cable, duplex mismatch, or faulty NIC

Answer

CRC errors indicate corrupted frames, most commonly caused by physical problems: damaged cables, duplex mismatches, or faulty hardware.

Question 4

A user cannot access a remote server but can ping the default gateway. What is the most likely issue?

Accepted Answer

Routing or firewall issue between the user's network and the server's network

Answer

If the gateway is reachable but the remote server is not, the problem lies beyond the local network — in routing, ACLs, or firewall rules in the path.

Question 5

What tool is used to identify the path packets take from a source to a destination and detect where delays occur?

Accepted Answer

traceroute / tracert

Answer

Traceroute (tracert on Windows) sends packets with increasing TTL values to discover each hop in the path and measure round-trip time at each hop.

NE - Network Engineer Practice Test

NE - Network Engineer Practice Test

NE NE Network Troubleshooting