CCENT Cisco Certified Entry Networking Technician Study Guide: (ICND1 Exam 640-822), 2nd Edition

Chapter 3: IP Subnetting, Troubleshooting IP, and Introduction to NAT

1. D. A /27 (255.255.255.224) is 3 bits on and 5 bits off. This provides 8 subnets, each with 30 hosts. Does it matter if this mask is used with a Class A, B, or C network address? Not at all. The amount of host bits would never change.
2. D. A 240 mask is 4 subnet bits and provides 16 subnets, each with 14 hosts. You need more subnets, so let's add subnet bits. One more subnet bit would be a 248 mask. This provides 5 subnet bits (32 subnets) with 3 host bits (6 hosts per subnet). This is the best answer.
3. C. This is a pretty simple question. A /28 is 255.255.255.240, which means that the block size is 16 in the fourth octet: 0, 16, 32, 48, 64, 80, and so on. The host is in the 64 ...