Kostis Netzwerkberatung
Konstantinos Kostis, Talstr. 25, D-63322 Rödermark
Tel. +49 6074 881056, FAX 881058
kosta@kostis.net, http://www.kostis.net/
You may use this information free of charge at your own risk
2001-06-27
| subnet mask | binary | alt | addresses |
| 255.0.0.0 | 11111111.00000000.00000000.00000000 | /8 | 16777216 |
| 255.128.0.0 | 11111111.10000000.00000000.00000000 | /9 | 8388608 |
| 255.192.0.0 | 11111111.11000000.00000000.00000000 | /10 | 4194304 |
| 255.224.0.0 | 11111111.11100000.00000000.00000000 | /11 | 2097152 |
| 255.240.0.0 | 11111111.11110000.00000000.00000000 | /12 | 1048576 |
| 255.248.0.0 | 11111111.11111000.00000000.00000000 | /13 | 524288 |
| 255.252.0.0 | 11111111.11111100.00000000.00000000 | /14 | 262144 |
| 255.254.0.0 | 11111111.11111110.00000000.00000000 | /15 | 131072 |
| 255.255.0.0 | 11111111.11111111.00000000.00000000 | /16 | 65536 |
| 255.255.128.0 | 11111111.11111111.10000000.00000000 | /17 | 32768 |
| 255.255.192.0 | 11111111.11111111.11000000.00000000 | /18 | 16384 |
| 255.255.224.0 | 11111111.11111111.11100000.00000000 | /19 | 8192 |
| 255.255.240.0 | 11111111.11111111.11110000.00000000 | /20 | 4096 |
| 255.255.248.0 | 11111111.11111111.11111000.00000000 | /21 | 2048 |
| 255.255.252.0 | 11111111.11111111.11111100.00000000 | /22 | 1024 |
| 255.255.254.0 | 11111111.11111111.11111110.00000000 | /23 | 512 |
| 255.255.255.0 | 11111111.11111111.11111111.00000000 | /24 | 256 |
| 255.255.255.128 | 11111111.11111111.11111111.10000000 | /25 | 128 |
| 255.255.255.192 | 11111111.11111111.11111111.11000000 | /26 | 64 |
| 255.255.255.224 | 11111111.11111111.11111111.11100000 | /27 | 32 |
| 255.255.255.240 | 11111111.11111111.11111111.11110000 | /28 | 16 |
| 255.255.255.248 | 11111111.11111111.11111111.11111000 | /29 | 8 |
| 255.255.255.252 | 11111111.11111111.11111111.11111100 | /30 | 4 |
| 255.255.255.255 | 11111111.11111111.11111111.11111111 | /32 | 1 |
Subnet mask 255.255.255.254 aka /31 is invalid, since there would be only the net address and the broadcast address. The number given under addresses should be read -2 for the network address and the broadcast address (except for /32). The number behind "/" is number of bits set to "1" (from left to right). This notation is way shorter. :)