On Sun, 14 Mar 1999, I Am Not An Isp wrote:
Nothing except community consensus that it is a *BAD* thing to pollute the global routing table with lots of long prefixes.
I am capable of putting /32s in my network an announcing the aggregate. We did this at Priori, Michael. Justin programmed each loopback as a /32 out of the same /24, so we had x.x.x.1 on the west coast and x.x.x.2 on the east coast, but still only announced the /18.
Most of the people on this list do not operate a national backbone. This aggregation technique is just fine if you really do have geographical diversity of nameserver location inside your AS. I'm not sure why anyone would go to the trouble of making it appear that their nameservers are in the same room when they are not. Priori had nameservers at PAIX and at Erols in Fairfax County, VA. But if a network does not have geographical diversity inside their AS then all of this /32 aggregation magic is for naught. If national backbones look like this: NS0.VERIO.NET 205.238.52.46 NS1.VERIO.NET 204.91.99.140 NS1.SPRINTLINK.NET 204.117.214.10 NS2.SPRINTLINK.NET 199.2.252.9 NS3.SPRINTLINK.NET 204.97.212.10 NS.CW.NET 204.70.128.1 NS2.CW.NET 204.70.57.242 NS3.CW.NET 204.70.25.234 NS4.CW.NET 204.70.49.234 then why wouldn't all ISPs look like this? NS1.EXAMPLE.COM 192.0.2.17 NS2.EXAMPLE.COM 204.97.212.10 NS3.EXAMPLE.COM 205.91.99.140 instead of the minimalist slapdash technique NS1.EXAMPLE.COM 192.0.2.44 NS2.EXAMPLE.COM 192.0.2.45 It's not hard to find an ISP in another state or another country to trade secondary DNS. And when the backhoe cuts a major fiber link in your area used by all three of your upstream providers, the world will know that you still exist. If you use the minimalist slapdash technique the world will think that you've gone out of business. -- Michael Dillon - E-mail: michael@memra.com Check the website for my Internet World articles - http://www.memra.com