David Lott: Thursday, September 14, 2000 10:34 AM wrote:
First, allow me to state the assumptions that I'm under. I understand the policy to state that if a business needs to multi-home and requires less space than a /20, then they should request this space from their ISP. I also understand that there are filters at the /20 boundaries in order to minimize the size of the routing table.
Question: Doesn't this break multi-homing for end users that need less than a /20?
Yep, this has been a topic here before...no real resolution. You didn't really need to prove the case, it has already been proven. The only way that you can do it is to justify a /20 or larger, get portable IP space from ARIN, and make your own peering arrangements with your upstreams. Considering that you will probably burn the best part of the /20 with distributed services, this increases your internal administration costs substantially. What you will have is a very low-density use net-block, but at least you can now multi-home and even have some geographical independence, for multiple-site use. If you have good admins, the whole thing can be folded/collapsed into about 20 physical servers, or less (Lintel boxen keep the costs low too, see: VA-Linux, about two racks). Is this wasteful of IP space? ...absolut! Is this necessary? ...sometimes. If you are building a H-Rel/Hi-Avail/Hi-Secure site(s), you ain't getting there without multi-homing with at least three providers. If you have multiple sites, you can't get there without multi-homing on an ASN that will be advertised (at least a /20, probably a /19). Do I tell clients this? ... absolut! Have I done this for clients? ... Yep, and I ain't saying who for either. --- R O E L A N D M . J . M E Y E R CEO, Morgan Hill Software Company, Inc. Managing Architect Tel: (925)373-3954 Fax: (925)373-9781 http://staff.mhsc.com/rmeyer