ICND2: Interconnecting Cisco Networking Devices Part 2 (legacy) — Question 78

The company internetwork is subnetted using 29 bits. Which wildcard mask should be used to configure an extended access list to permit or deny access to an entire subnetwork?

Answer options

• A. 255.255.255.224
• B. 255.255.255.248
• C. 0.0.0.224
• D. 0.0.0.8
• E. 0.0.0.7
• F. 0.0.0.3

Correct answer: E

Explanation

The correct answer is E (0.0.0.7) as it corresponds to the subnet mask of /29, which allows for 8 IP addresses (6 usable) and thus requires a wildcard mask of 0.0.0.7 to match all addresses in that subnet. The other options either represent incorrect wildcard masks or do not align with the required subnet. For example, A and B are subnet masks rather than wildcard masks.