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Zorluk: OrtaTroubleshooting Routing, Default Gateways, and ACLs

A network technician is troubleshooting a network outage where hosts on VLAN 30 (192.168.30.0/24192.168.30.0/24) are unable to reach an internal application server on VLAN 50 (192.168.50.10192.168.50.10). Following the CompTIA network troubleshooting methodology, place the actions in the correct sequential order from first step to last step.

  1. 1Gather network symptoms by questioning affected users and examining diagnostic command outputs (`ping` and `traceroute`) from VLAN 30 workstations.
  2. 2Formulate a hypothesis that an Access Control List (ACL) on the intervening router interface is improperly blocking traffic from VLAN 30 to VLAN 50.
  3. 3Run `show ip access-lists` on the router to inspect packet drop counters and confirm whether traffic matches an implicit deny rule.
  4. 4Draft a change management plan detailing the modified ACL permit statement placement and assessing potential security impact.
  5. 5Apply the corrected ACL to the gateway router interface and verify that VLAN 30 hosts can successfully establish connections to VLAN 50.
  6. 6Log the root cause, updated ACL syntax, and testing verification results into the network change management ticketing system.

Cevap

The correct order follows the CompTIA Network Troubleshooting Methodology: 1. Gather network symptoms, 2. Formulate a hypothesis (theory of probable cause), 3. Inspect ACL rules with show commands (test the theory), 4. Draft a change plan, 5. Apply corrected ACL and verify connectivity (implement and verify), 6. Log findings and resolution in tickets (document outcomes).
The correct sequence aligns strictly with the 7-step CompTIA network troubleshooting methodology: (1) Identify the problem by gathering symptoms, (2) Establish a theory of probable cause, (3) Test the theory to determine cause, (4) Establish a plan of action, (5) Implement the solution and verify full system functionality, and (6) Document findings, actions, and outcomes.

Adım Adım Çözüm

1
Identify the problem
Information gathered from affected users and initial diagnostic commands.
Troubleshooting must begin with identifying symptoms and scope.
2
Establish a theory of probable cause
Hypothesis generated regarding an ACL blocking cross-VLAN traffic.
Developing a logical theory focuses diagnostic efforts.
3
Test the theory
Router ACL inspection confirms traffic hits an implicit deny statement.
Testing validates whether the hypothesis is accurate before making network modifications.
4
Establish a plan of action
Change request drafted detailing syntax changes and risk assessment.
Planning ensures changes are controlled and potential unintended consequences are mitigated.
5
Implement solution & verify functionality
ACL updated on router interface and ping/traceroute tests confirm restored access.
The fix must be deployed and validated to ensure the issue is completely resolved.
6
Document findings
Ticket updated with root cause, ACL configuration details, and resolution status.
Proper documentation preserves operational knowledge for future incidents.

Anahtar Kavram

CompTIA Network Troubleshooting Methodology applied to Routing and ACL issues
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