CCNA: Cisco Certified Network Associate — Question 7

An engineer must configure a /30 subnet between two routes. Which usable IP address and subnet mask combination meets this criteria?

Answer options

• A. interface e0/0 description to XX-AXXX:XXXXX ip address 10.2.1.3 255.255.255.252
• B. interface e0/0 description to XX-AXXX:XXXXX ip address 192.168.1.1 255.255.255.248
• C. interface e0/0 description to XX-AXXX:XXXXX ip address 172.16.1.4 255.255.255.248
• D. interface e0/0 description to XX-AXXX:XXXXX ip address 209.165.201.2 225.255.255.252

Correct answer: D

Explanation

The correct answer is D because 209.165.201.2 with a subnet mask of 255.255.255.252 provides a valid usable IP address within a /30 subnet, allowing for two usable addresses. Options A, B, and C are incorrect because they either use incorrect subnet masks for a /30 configuration or have IP addresses that do not fit within the /30 subnet range.