nanog mailing list archives
Re: IP address fee??
From: Ted Fischer <ted () fred net>
Date: Fri, 06 Sep 2002 12:58:22 -0400
At 12:42 PM 9/6/02 -0400, you wrote:
Was this reply directed at me, particularly? Joe
Joe,Most definitely not. I felt that the two comments I included most closely represented the discussion and information I wanted to pass.
No offense meant, I hope none taken, apologies if they were. Ted
On Fri, Sep 06, 2002 at 12:33:09PM -0400, Ted Fischer wrote: > At 10:00 AM 9/6/02 -0400, Joe Abley postulated: > > >On Thu, Sep 05, 2002 at 01:13:27PM -0500, Stephen Sprunk wrote: > >> Because "Cee" is easier to pronounce than "slash twenty-four". Ease of > >use > >> trumps open standards yet again :) > > > >Nobody was talking. "/24" is easier to type than "class C". No > >trumps! Everybody loses! > > > >How many people learn about networks from certification courses or > >in school, anyway? It was always my impression that people learnt > >mainly by listening to other people. > > > >If networking on the front lines is an informal oral tradition more > >than it is a taught science, then perhaps it's natural for obsolete > >terminology to continue to be "taught" long after it stopped having > >any relevance. > > > > > >Joe > > The class of an address is determined by the bit-pattern of the first > octet of the address. 10.0.0.0 will always be a Class A> address. 172.16.0.0 will always be a Class B address, and 192.168.0.0 will> always be Class C address. I'm not aware of any RFC that rescinded the > definition of the Class of an address. > > Masks, when associated with an address, enable one to determine (a), > what network I'm on (if I'm an IP host) or (b) how many addresses exist > within a given range of addresses (if I'm a routing table). > > Subnetting (robbing mask host bits (0's) to make network bits (1's)> allowed one to more effectively use the decreasing amounts of networks that > required less than the default number of addresses (65,536 in the case of a> Class B) by more effeciently using the space one had been allocated. With > subnetting, I can take one Classful network and make many (sub)networks> from it. There was no way prior to 1993, however, to effectively represent> the range of addresses in more than one Classful network. > > CIDR, simply stated, says that one can use any address with any mask, > regardless of the original class of the address, to represent a range of > addresses (i.e. rob network bits to make host bits). It allows the > properties of IP to be more effectively used for IP host addressing (only > need a /23 to support 400 IP hosts (a very effecient 78% use of the > allocated space), as well as (one of the original, primary reasons for > CIDR) aggregate ("Supernet") "X" traditional Class C's into one routing > statement (who today would advertise delivery to the range of 4,096 > addresses from, for example, 192.168.192.0 through 192.168.207.255 with 16 > individual traditional Class C statements?). > > Since NANOG is "the front line", then perhaps that is where the oral > tradition should be teaching the history of IP addressing, from Classful > addressing (default masks) to Subnetting (other than default) to> Supernetting (ranges of addresses regardless of original - or legacy if you> will - class (Classless)). > > The prefix, of course, does not refer to the class of the address, but > the number of contiguous ones in the mask. As far as pronounciation goes, > I prefer "slash 24" to "two fifty five dot two fifty five dot two fifty > five dot zero" :) > > $.02 > > Ted Fischer >
Current thread:
- Re: classless delegation [Re: IP address fee??], (continued)
- Re: classless delegation [Re: IP address fee??] Peter van Dijk (Sep 09)
- Re: classless delegation [Re: IP address fee??] Brad Knowles (Sep 09)
- RE: classless delegation [Re: IP address fee??] Jeroen Massar (Sep 06)
- RE: classless delegation [Re: IP address fee??] Jeroen Massar (Sep 06)
- RE: classless delegation [Re: IP address fee??] Brad Knowles (Sep 06)
- Re: classless delegation [Re: IP address fee??] Peter van Dijk (Sep 09)
- Re: IP address fee?? Christopher Schulte (Sep 05)
- Re: IP address fee?? Stephen Sprunk (Sep 05)
- Re: IP address fee?? Forrest W. Christian (Sep 05)
- Re: IP address fee?? Forrest W. Christian (Sep 05)
- Message not available
- Re: IP address fee?? Ted Fischer (Sep 06)
- Re: IP address fee?? bdragon (Sep 08)
- Re: IP address fee?? Stephen J. Wilcox (Sep 09)
- Re: IP address fee?? David Schwartz (Sep 05)
- Re: IP address fee?? bdragon (Sep 08)
- Re: IP address fee?? Stephen J. Wilcox (Sep 09)
- Re: IP address fee?? cw (Sep 09)
- Re: IP address fee?? Stephen J. Wilcox (Sep 09)