100-150 Question 176
Select 2A network administrator is troubleshooting a connectivity issue between two routers in different subnets. Both routers have static routes configured. The administrator realizes that packets are being sent from Router A to Router B, but Router B is not sending responses back to Router A. Which of the following could be the cause of this issue?
- A
Router B does not have a static route pointing back to Router A's subnet.
- B
Router A has a misconfigured default gateway.
- C
The interfaces on Router B are administratively down.
- D
Router B's firewall is blocking return traffic.
Show answer and explanation
Correct answers: A, D
Explanation
For successful communication between two routers, routing must be configured properly in both directions. If Router B does not have a static route back to Router A's subnet, or if a firewall on Router B is blocking return traffic, the communication will fail as described in the scenario.
- A. Correct.
If Router B does not have a static route pointing back to Router A’s subnet, it will not know how to route return traffic, causing the issue described.
- B. Incorrect.
A misconfigured default gateway on Router A would prevent it from sending packets to Router B in the first place, but that is not the issue described here as packets are successfully reaching Router B.
- C. Incorrect.
If the interfaces on Router B were administratively down, Router A's packets would not reach Router B, but the question states that packets are being sent successfully.
- D. Correct.
If Router B's firewall is configured to block return traffic, Router B would not send packets back to Router A, which matches the symptoms described.