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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: BGP4 on a /20
If all the customers on a multi-billion dollar network could not reach my network I would think about paying a different upstream provider to peer with me. I announce a /19 and a /22 to NetRail and UUnet, and they both do an excellent job of getting Sprint's customers routed to my network. Marcus R. Williams, Jr. [email protected] ISP Programmer / Engineer On Fri, 19 Sep 1997, Brian Horvitz wrote: > Date: Fri, 19 Sep 1997 10:54:05 -0400 > From: Brian Horvitz <[email protected]> > To: Security Administrator <[email protected]> > Subject: Re: BGP4 on a /20 > > Because if all the customers on a multi-billion dollar network can't get to > him it's not real good. > > Brian > > At 10:32 AM 9/19/97 -0400, you wrote: > >Why should you concern yourself with the problems of a multi-billion > >dollar company like Sprint? > > > >Marcus R. Williams, Jr. > >[email protected] > >ISP Programmer / Engineer > > > >On Thu, 18 Sep 1997, Phil Howard wrote: > > > >> Date: Thu, 18 Sep 1997 18:22:19 -0500 > >> From: Phil Howard <[email protected]> > >> To: [email protected] > >> Subject: BGP4 on a /20 > >> > >> I'm trying to understand what all the implications of running BGP4 on > >> a network with a prefix longer than 19 bits. Here are some of the points > >> I am thinking about. > >> > >> <flameshields> > >> > >> If I go ahead and announce a /20 via two backbones, one of which is > >> the provider of the address space, then there will be redundant routes > >> for this space as the backbone provider will be announcing the /19 > >> (or shorter) block themselves. > >> > >> If I do this, it adds to the routing table glut, among other things. > >> The advantage gained is questionable. If my link to the provider that > >> the space comes from goes down, they are still announcing and I'll only > >> be able to reach where my path via the alternate provider is shorter > >> than the path to the down provider itself. > >> > >> OTOH > >> > >> If the provider were to be convinced to stop announcing for my /20, > >> then I'm going to get filtered at Sprint and AGIS and whoever else > >> is doing this and there won't be any /19 announcement that I can use > >> a default path on. > >> > >> But the real catch here is that for the provider to stop announcing > >> my /20 they have to split their /19 into two /20's. And if that was > >> really a /18 that means they will be announcing a /19 and a /20 where > >> before only a /18. This gets worse the larger their block was. > >> > >> Even worse than that, by doing this, they now have a /20 (the other > >> half of the /19 my /20 is in) with other customers who will now also > >> be filtered out at Sprint and AGIS and whoever else. While it can be > >> OK to me if I want to give up that reachability, this is also imposing > >> this on the other customer(s) in the other /20. So that provider is > >> not even likely to do that. > >> > >> So, should I add to the glut of routes or should I add to the glut of > >> routes? > >> > >> This needs to be simpler. > >> > >> </flameshields> > >> > >> -- > >> Phil Howard > +-------------------------------------------------------------+ > >> KA9WGN | House committee changes freedom bill to privacy invasion > !! | > >> phil at | more info: > http://www.news.com/News/Item/0,4,14180,00.html | > >> milepost.com > +-------------------------------------------------------------+ > >> > > > > >
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