Chapter 10, Set A — answers
| # | Given | Network | Broadcast | Usable range | Hosts |
|---|---|---|---|---|---|
| 1 | 192.168.10.75 /24 | 192.168.10.0 | 192.168.10.255 | .1 – .254 | 254 |
| 2 | 192.168.10.75 /26 | 192.168.10.64 | 192.168.10.127 | .65 – .126 | 62 |
| 3 | 10.5.3.200 /25 | 10.5.3.128 | 10.5.3.255 | .129 – .254 | 126 |
| 4 | 172.20.15.100 /28 | 172.20.15.96 | 172.20.15.111 | .97 – .110 | 14 |
| 5 | 10.0.0.6 /30 | 10.0.0.4 | 10.0.0.7 | .5 – .6 | 2 |
| 6 | 192.168.4.170 /27 | 192.168.4.160 | 192.168.4.191 | .161 – .190 | 30 |
| 7 | 172.16.35.42 /23 | 172.16.34.0 | 172.16.35.255 | 172.16.34.1 – 172.16.35.254 | 510 |
| 8 | 10.10.10.10 /22 | 10.10.8.0 | 10.10.11.255 | 10.10.8.1 – 10.10.11.254 | 1022 |
Working for #7: /23 → mask 255.255.254.0 → block size 256−254 = 2, in the
third octet. Count in 2s: 0, 2, 4 … 34, 36. 35 falls in the 34 block.
Working for #8: /22 → mask 255.255.252.0 → block size 4 in the third
octet. Count: 0, 4, 8, 12. 10 falls in the 8 block.