nanog mailing list archives
Re: classful routes redux
From: Kevin Loch <kloch () hotnic net>
Date: Wed, 02 Nov 2005 20:14:03 -0500
Bill Woodcock wrote:
On Wed, 2 Nov 2005, Fred Baker wrote:> While I think /32, /48, /56, and /64 are reasonable prefix lengths > for what they are proposed for, I have this feeling of early > fossilization when it doesn't necessarily make sense.Yeah, that's what seems important to me here... I mean, I've lived through the whole classful thing once... I'm still not clear why there are people who want to do it again.
It's not quite the same as classful addressing in IPv4. There is no definition of prefix length by address range. At the RIR->ISP level It is actually CIDR with a minimum allocation size that intentionally covers 95+% of applicants. Shorter allocations of various sizes are made based on justification. An extra 1-3 bits is even reserved around each allocation for future growth. The same thing applies to End sites. You can get a /47 or shorter with justification. It's might be rare but it is possible. I think the goal was to avoid making multiple non-aggregatable allocations as is done with IPv4. An alternative would be to allocate based on initial need but still reserve a much larger prefix for future growth. This would avoid the illusion of fixed sizes and carry less risk of unused space. Is that worth the extra RIR effort? Maybe, maybe not. - Kevin
Current thread:
- RE: Using BGP to force inbound and outbound routing through particular routes, (continued)
- RE: Using BGP to force inbound and outbound routing through particular routes John Dupuy (Nov 02)
- Re: Using BGP to force inbound and outbound routing through particular routes Richard A Steenbergen (Nov 02)
- Re: Using BGP to force inbound and outbound routing through particular routes Joe McGuckin (Nov 02)
- Re: Using BGP to force inbound and outbound routing through particular routes Randy Bush (Nov 02)
- Re: Using BGP to force inbound and outbound routing through particular routes Richard A Steenbergen (Nov 02)
- classful routes redux bmanning (Nov 02)
- Re: classful routes redux Fred Baker (Nov 02)
- Re: classful routes redux Bill Woodcock (Nov 02)
- Re: classful routes redux Fred Baker (Nov 02)
- Re: classful routes redux Bill Woodcock (Nov 02)
- Re: classful routes redux Kevin Loch (Nov 02)
- Re: classful routes redux Richard A Steenbergen (Nov 05)
- Re: classful routes redux Geoff Huston (Nov 05)
- Re: classful routes redux Niels Bakker (Nov 02)
- Re: classful routes redux Stephen J. Wilcox (Nov 02)
- Re: classful routes redux Todd Vierling (Nov 03)
- Re: classful routes redux Richard A Steenbergen (Nov 03)
- Re: classful routes redux Stephen J. Wilcox (Nov 03)
- Re: classful routes redux bmanning (Nov 03)
- Re: classful routes redux Patrick W. Gilmore (Nov 03)
- Re: classful routes redux Russ White (Nov 04)