North American Network Operators Group Date Prev  Date Next  Date Index  Thread Index  Author Index  Historical Re: The Mathematical Reality of IP Addressin in IPv4...
At 10:43 AM 8/26/99 0700, [email protected] wrote: > >> What this proposal appears to be proposing is to permit NONCONTIGUOUS >> netmasks such as: >> >> 255.128.127.0 >> >> Or, in binary: >> >> 1111111111 10000000 01111111 00000000 >> >> Thus, the network number would actually consist of all 8 bits of octet >> one, the first bit of octet two, the last 7 bits of octet 3 and none of >> octed four. >> > >Noncontigious masks were allowed up until the CIDR era... :) > >bill > As an exercise in insanity, when I teach my TCP/IP course, I use the following example 206.183.244.0 / 255.255.255.170 and ask the students to find the subnet address, first usable node, last usable node and broadcast address for each subnet. Takes them about three hours and then they appreciate the recommendation that all subnet bits be contiguous. What it does do very well is hammer home how these things actually work in terms of varying the host bits and network bits :) eric ========================================================================== Eric Germann CCTec [email protected] Van Wert, OH 45891 http://www.cctec.com Ph: 419 968 2640 ICQ: 41927048 Fax: 419 968 2641 Network Design, Connectivity & System Integration Services A Microsoft Solution Provider
