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Re: Routing Question-- Maybe a hack
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you may well be right. it's worthy of experimentation...

/jws

> > Yea, I agree but I would say that practically, the http queries are so short > lived that the edge case probably doesn't matter that much. The only thing > that might happen in the case is that during a routing chane and doing the > querie, the flow fails and when the client "clicks" again, it should work. > > Jack > > At 10:24 AM 12/13/95 -0500, John W. Stewart III wrote: > > > >i brought up dns as a way of describing a service that would > >most definitely work well using jack's proposal. the is as > >opposed to http which might not work so well... > > > >the point is that this host route approach may work ok for > >connectionless, single-packet-request, single-packet-response > >services like dns queries. however, the approach might not > >work so well for connection-oriented multi-packet services > >like http. if routing changes in some way, then one of the > >http servers could enter into a tcp connection "in the middle > >of a conversation" and the client would be messed up... > > > >/jws > > > > > Sorry to be dense about this. We don't have to do anything > > > to DNS (e.g., BIND)? DNS does the right thing because routes are pointi ng > > > you to the right place? I can live with the right answer for hosts > > > directly on the railroad ... we can worry about the other sites > > > later. > > > > > > Carl > > > > > > According to John W. Stewart III: > > > > > > > > > > > > the addressing issues are key here > > > > > > > > this idea is a slight modification to an idea we've had for > > > > sharing the load of dns queries. in that case, however, the > > > > address of the name servers is within an aggregate that we > > > > announce .. so the whole internet comes to us, and then we > > > > use the host route within our backbone to optimize routing. > > > > if you've got servers off of your backbone, then it gets > > > > harder .. and you probably don't want to inject /32s into > > > > the global routing mesh > > > > > > > > a difference between dns and http is that dns is a single- > > > > query, connectionless service while http is longer-lived and > > > > connection-oriented. the life of an http connection *is* > > > > relatively short, but since it's more than one packet, in an > > > > event where a server goes down, clients will not see a > > > > graceful transition > > > > > > > > /jws > > > > > > > > > Wow! Let me see if I get this. What happens when a Japanese user > > > > > types http://www.park.org/ is: > > > > > > > > > > 1) www.park.org resolves to 5.6.7.8 > > > > > 2) the packet goes to the railroad > > > > > 3) the "best" route to 5.6.7.8 in this case > > > > > is right back into the Japanese infrastructure > > > > > > > > > > If a user in Australia does the same thing, they get pointed to the > > > > > edge of the railroad (Mae-East in this case) and the "best route" > > > > > to 5.6.7.8 in this case is town.hall.org. > > > > > > > > > > I think this works for hosts directly on the railroad. What if > > > > > we have a central park server already in Australia, but not on > > > > > the railroad? How does that work? > > > > > > > > > > Carl > > > > > > > > > > According to Jack Waters: > > > > > > > > > > > > Carl > > > > > > > > > > > > I thought about this a bit last night and wanted to throw out a p ossi > >ble > > > > > > solution. The real goal I think you have is to make web client us e th > >e > > > > > > closest web server. > > > > > > > > > > > > Here's my proposal: > > > > > > > > > > > > On each worlds fair server, let's say two for now (call it > > > > > > www.worldsfair.org for now): > > > > > > > > > > > > Create two interfaces for > > > > > > > > > > > > 1) Machine1 > > > > > > le0 --> 1.2.3.4 (the real address of the machine) > > > > > > vif0 --> 5.6.7.8 (the pseudo address of www.worldsfair.org) > > > > > > 2) Machine2 > > > > > > le0 --> 9.0.1.2 (the real address of the machine) > > > > > > vif0 --> 5.6.7.8 (the pseudo address of www.worldsfair.org) > > > > > > > > > > > > In the DNS www.worldsfair.org would only map to 5.6.7.8 > > > > > > > > > > > > Then in the railroad infrastructure, import the host route 5.6.7. 8 in > >to th > > > > e > > > > > > IGP (presumably OSPF or ISIS) pointing to both machine1[2]. > > > > > > > > > > > > With this, when a client resolves www.worldsfair.org, it will go to 5 > >.6.7. > > > > 8 > > > > > > which will be routed, once inside the railroad, to the *closest* 5.6. > >7.8 a > > > > nd > > > > > > get to the closest (IGP-wise) web server. > > > > > > > >> > > The trick will be to make the host route dynamic enough to remove it s > > > > > > announcement for one of the machines[1 || 2] when that machine (o r mo > >re > > > > > > specifically httpd) is not available. This should be pretty easy to d > >o if > > > > > > you use gated on machine1[2]. A quick hack to remove the route fr om g > >ated > > > > > > could be implemented to "watch" httpd and remove the announcement . Of > > > > > > course, gated will automatically remove the announcement if the m achi > >ne > > > > > > becomes diconnected or dies. > > > > > > > > > > > > This, I think, should accomplish what you are trying to do. Let m e kn > >ow wh > > > > at > > > > > > you think. > > > > > > > > > > > > Thanks > > > > > > Jack > > > > > > > > > > > > > > > > > > > > > > > > Note the second interface is a > > > > > > > > > > > > At 11:13 AM 12/12/95 -0500, Carl Malamud [IMS] wrote: > > > > > > >> if you're talking about multiple servers in different > > > > > > >> locations with clients routing to them based on proximity > > > > > > >> that's very different. perhaps possible. > > > > > > > > > > > > > >You bet, that is what we want to do. Different answers for > > > > > > >different locations. I'll call Kim Claffy and see what she > > > > > > >has to contribute. > > > > > > > > > > > > > >How hard is it to manually define some border AS's (e.g., the > > > > > > >ones at the "edge" of Japan) and then ask the question: is this > > > > > > >IP address "beyond" the border AS's? From a host, what would > > > > > > >I do to ask that question? > > > > > > > > > > > > > >Carl > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >

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