On Sunday 03 February 2008 09:37, James Knott wrote:
...
IP address classes have been depreciated for many years, in favour of Classless Inter-Domain Routing (CIDR), where you specify the subnet mask directly, instead of relying on address ranges. http://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing This means it is entirely permissible to have subnets greater than 256 addresses in the 192.168.x.x range. So, please forget about Class A, B or C addresses. They're no longer relevant.
While that's true, the private ranges defined in the pertinent specification don't allow arbitrary subnet masks nor arbitrary network numbers. According to RFC 1918 (a "Best Current Practice" RFC): 3. Private Address Space The Internet Assigned Numbers Authority (IANA) has reserved the following three blocks of the IP address space for private internets: 10.0.0.0 - 10.255.255.255 (10/8 prefix) 172.16.0.0 - 172.31.255.255 (172.16/12 prefix) 192.168.0.0 - 192.168.255.255 (192.168/16 prefix) We will refer to the first block as "24-bit block", the second as "20-bit block", and to the third as "16-bit" block. Note that (in pre-CIDR notation) the first block is nothing but a single class A network number, while the second block is a set of 16 contiguous class B network numbers, and third block is a set of 256 contiguous class C network numbers. Randall Schulz -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org