Le jeudi 24 mars 2011 à 14:26 -0700, Bill Woodcock a écrit : > On Mar 24, 2011, at 1:47 PM, Patrick W. Gilmore wrote: > > On Mar 24, 2011, at 3:40 PM, Owen DeLong wrote: > >> On Mar 24, 2011, at 12:42 PM, Zaid Ali <z...@zaidali.com> wrote: > >> > >>> I have seen age old discussions on single AS vs multiple AS for backbone > >>> and datacenter design. I am particularly interested in operational > >>> challenges for running AS per region e.g. one AS for US, one EU etc or I > >>> have heard folks do one AS per DC. I particularly don't see any advantage > >>> in doing one AS per region or datacenter since most of the reasons I hear > >>> is to reduce the iBGP mesh. I generally prefer one AS and making use of > >>> confederation. > >> > >> If you have good backbone between the locations, then, it's mostly a > >> matter of personal preference. If you have discreet autonomous sites that > >> are not connected by internal circuits (not VPNs), then, AS per site is > >> greatly preferable. > > > > We disagree. > > Single AS worldwide is fine with or without a backbone. > > Which is "preferable" is up to you, your situation, and your personal > > tastes. > > > We're with Patrick on this one. We operate a single AS across > seventy-some-odd locations in dozens of countries, with very little of what > an eyeball operator would call "backbone" between them, and we've never seen > any potential benefit from splitting them. I think the management headache > alone would be sufficient to make it unattractive to us. > > -Bill > >
Right. I think that a single AS is most often quite fine. I think our problem space is rather about how you organise the routing in your AS. Flat, route-reflection, confederations? How much policing between regions do you feel that you need? In some scenarios, I think confederations may be a pretty sound replacement of the multiple-AS approach. Policing iBGP sessions in a route-reflector topology? Limits? Thoughts? Cheers, mh > > > >
