Examkin

Question

Difficulty: MediumTroubleshooting Routing, Default Gateways, and ACLs

A network administrator receives a ticket stating that a newly deployed application server at 192.168.20.5/24192.168.20.5/24 cannot reach a remote database server located on a different subnet at 10.1.50.10/2410.1.50.10/24. Place the following diagnostic and remediation steps in the correct logical troubleshooting sequence to isolate and resolve the issue.

  1. 1Verify the application server's local IP address, subnet mask, and default gateway configuration.
  2. 2Execute a ping command from the application server to its local default gateway IP address.
  3. 3Run a traceroute command from the application server targeting 10.1.50.1010.1.50.10 to locate the specific hop where packets stop forwarding.
  4. 4Examine the routing table and inbound/outbound Access Control Lists (ACLs) on the router interface corresponding to the failing hop.
  5. 5Update the ACL rule or routing table entry, then perform an end-to-end ping to verify full reachability.

Answer

The correct logical order begins with checking local host IP configuration (item 1), testing local gateway reachability (item 2), tracing the path to isolate the failing hop (item 3), inspecting the routing table and ACLs at that hop (item 4), and finally applying the fix and verifying end-to-end connectivity (item 5).
Standard network troubleshooting proceeds methodically from the host level outward: verify host parameters, test local gateway reachability, perform path analysis to locate the failing hop, evaluate routing and ACL configurations on that device, and verify resolution.

Step-by-Step Solution

1
Verify local host IP configuration
Ensures the host has a valid IP address, mask, and default gateway setting
Rule out basic local misconfigurations before investigating network infrastructure.
2
Ping the local default gateway
Confirms Layer 2 and Layer 3 reachability within the local broadcast domain
Isolates whether the problem is on the local LAN segment or across routed bounds.
3
Perform path tracing using traceroute
Pinpoints the exact intermediate router or firewall hop where ICMP/IP packets stop
Narrows the scope of investigation to a specific network device.
4
Analyze routing entries and ACL statements on the target hop device
Determines if packets are dropped due to a missing static/dynamic route or blocked by an implicit/explicit deny rule
Identifies the precise root cause of the forwarding failure.
5
Implement corrective configuration and conduct end-to-end validation
Restores bidirectional IP communication and verifies solution effectiveness
Confirms resolution without leaving unverified changes in production.

Key Concept

CompTIA Troubleshooting Methodology applied to Routing, Default Gateways, and ACLs
Rate this question

Topics

Troubleshooting Routing, Default Gateways, and ACLs

More questions from this topic