Randall R Schulz wrote:
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
I don't see how the above is relevant to the discussion. It's doing nothing more than describing the available private network ranges and not how they're used. That is, if you're hiding behind a NAT router, your addresses must use the above ranges. It does not say you can only use 24 bit sub net masks on your local 192.168.x.x network, as would be implied by a Class C address. -- Use OpenOffice.org <http://www.openoffice.org> -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org