JNCIS-SP: Juniper Networks Certified Specialist – Service Provider Routing (2023) — Question 10

An OSPF router does not have a router ID configured.
In this scenario, which statement is correct about the router ID?

Answer options

• A. The Junos OS will use the IP address assigned to the interface with the lowest MAC address.
• B. The Junos OS will use the IP address assigned to the loopback interface for the router ID.
• C. A router ID will not be assigned until it is manually configured.
• D. The Junos OS will use the IP address assigned to the interface with the highest priority.

Correct answer: B

Explanation

The correct answer is B because the Junos OS defaults to using the loopback interface's IP address for the router ID if none is configured. Option A is inaccurate because the MAC address does not influence the router ID selection. Option C is misleading as the system does assign a router ID automatically based on its criteria. Option D is incorrect since the interface priority does not determine the router ID in this context.