nanog mailing list archives
Re: The Mathematical Reality of IP Addressin in IPv4...
From: Eric Germann <ekgermann () cctec com>
Date: Thu, 26 Aug 1999 17:45:39 -0400
At 10:43 AM 8/26/99 -0700, bmanning () vacation karoshi com wrote:
What this proposal appears to be proposing is to permit NON-CONTIGUOUS 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.Non-contigious 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 ekgermann () cctec com 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
Current thread:
- The Mathematical Reality of IP Addressin in IPv4... J.D. Falk (Aug 25)
- Re: The Mathematical Reality of IP Addressin in IPv4... Jon Green (Aug 25)
- Re: The Mathematical Reality of IP Addressin in IPv4... Craig A. Haney (Aug 25)
- Re: The Mathematical Reality of IP Addressin in IPv4... Alex P. Rudnev (Aug 26)
- Re: The Mathematical Reality of IP Addressin in IPv4... Forrest W. Christian (Aug 26)
- Re: The Mathematical Reality of IP Addressin in IPv4... bmanning (Aug 26)
- Re: The Mathematical Reality of IP Addressin in IPv4... Eric Germann (Aug 26)
- Re: The Mathematical Reality of IP Addressin in IPv4... Alex P. Rudnev (Aug 27)
- Re: The Mathematical Reality of IP Addressin in IPv4... Stephen Sprunk (Aug 27)
- Re: The Mathematical Reality of IP Addressin in IPv4... Alex P. Rudnev (Aug 27)
- Re: The Mathematical Reality of IP Addressin in IPv4... Craig A. Haney (Aug 25)
- Re: The Mathematical Reality of IP Addressin in IPv4... Jon Green (Aug 25)
- Re: The Mathematical Reality of IP Addressin in IPv4... Craig A. Haney (Aug 25)
- Re: The Mathematical Reality of IP Addressin in IPv4... Alex P. Rudnev (Aug 26)
- <Possible follow-ups>
- Re: The Mathematical Reality of IP Addressin in IPv4... Vadim Antonov (Aug 25)
- Re: The Mathematical Reality of IP Addressin in IPv4... Forrest W. Christian (Aug 25)