A,B and C-Class Networks
A-class networks
- first 8 bits fixed, from 0-126 (only 127)
- very large companies like IBM, BBN, DEC,HP
- can assign 3 dotted quads - up to 16.7 million hosts
B-class networks
- first 16 bits fixed, first quad 128-191 and second 0-255 (16,384)
- Medium-sized companies like Microsoft, Exxon
- can assign 2 dotted quads - up to 65,536 hosts
C-class networks
- first 24 bits fixed, first quad 192-223, second and third 0-255 (2,097,152)
- can assign 1 dotted quad - up to 253 hosts, 0 is the subnet address., 1 default router address, 255 broadcast address.