Date: Mon, 29 Jan 1996 11:15:32 +0100 (MET) From: "Brian Carpenter CERN-CN" <brian@dxcoms.cern.ch> Message-ID: <9601291015.AA08851@dxcoms.cern.ch> 1. [..] I must state that the IAB has absolutely no role [..] Absolutely. 2. [..] I can tell you that we are in favour of technology that conserves address space and facilitates renumbering. Again, absolutely. I should say here though that that technology doesn't exist yet. My brother happens to be a customer of Demon's. He has one of those statically assigned IP addresses for a dial up customer (he's just a PC at home and typically a few minutes a day). That sounds like a perfect place for a dynamic address, however, if he had that, it would make life harder for me. With his static address I can instal filters to give him more access to my system at home (which is basically permanently connected, and not a PC) than I allow all the rest of you. (For Tony's benefit - no, this is not relying on source address filtering, I actually filter the packets that my system sends out, I will let it send packets to him that I won't let it send elsewhere, which has basically the same effect). While I have no doubt that not all of Demon's customers have requirements or uses anything like this, simply outlawing static addresses for dial up uses seems to me to be going a little too far. At least until we have the mechanisms that would make this need redundant (like dynamic DNS updates, and IP security widely deployed), plus good renumbering. Incidentally, absolutely no-one seems to doubt that if I have two systems at home, on a baby-lan, I can have a /29 or /30 statically assigned to me (at 50% or less address effeciency), but that if I have just one it seems I'm not supposed to have a /32 (100% address effeciency). Weird... kre

On Mon, 29 Jan 1996, Piet Beertema wrote:

Demon Internet Services provide an IP address for every dial-up customer. Most other ISPs have taken the view that this is a waste of valuable IP space and allocate IP addresses dynamically. How should our industry respond to ISPs who behave selfishly and do not take into account the good of the network? Is it just selfish or do they have good reasons? Dynamic address assignment and (static!) access control don't go very well together, which could be a reason for static address assignment.

Demon have spent a great deal of time and energy developing a system which allows customers (who have individual IP addresses) to dial in to any one of a number of PoPs and have their mail etc automatically routed to them; the IP number is dynamically bound to the particular modem they are coming in on at run time. They are justifiably proud of this system. I believe that someone from Demon has also pointed out that it is much more efficient that the usual "class C per customer" approach, which assigns 256 addresses to half a dozen machines. We strongly encourage our customers, most of whom are providers, to use dynamic routing for dial up, but we can understand Demon's situation ... and find it hard to condemn them when there are so many more glaring examples of waste of IP address space. -- Jim Dixon VBCnet GB Ltd +44 117 929 1316 fax +44 117 927 2015 VBCnet West +1 408 971 2682 fax +1 408 971 2684