Gotcha. Setup a Quagga/Bird box. Do your top talker analysis , use that box to inject the routes you deem important with communities. On your routers , create policy structure to only take a default plus those communities.
Obviously lots of devils in the details of the implementation , but something like that is all you need to do. On Fri, Jan 6, 2023 at 10:29 Mike Hammett <na...@ics-il.net> wrote: > Maybe? > > I don't need any additional performance tests, though. Just watching which > prefixes are the top talkers and leaving the rest to default. > > I'm not looking at this to do what a BGP optimizier would do and find the > best tested path to the top talkers and then massage BGP to get it routed > that way. Determine the top talkers, then let BGP do its thing for those > top talkers. > > I don't want to manually say X traffic from Y POP manually goes here, but > I don't want to just leave it to default routing either. Something in the > middle. > > > > ----- > Mike Hammett > Intelligent Computing Solutions <http://www.ics-il.com/> > <https://www.facebook.com/ICSIL> > <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> > <https://www.linkedin.com/company/intelligent-computing-solutions> > <https://twitter.com/ICSIL> > Midwest Internet Exchange <http://www.midwest-ix.com/> > <https://www.facebook.com/mdwestix> > <https://www.linkedin.com/company/midwest-internet-exchange> > <https://twitter.com/mdwestix> > The Brothers WISP <http://www.thebrotherswisp.com/> > <https://www.facebook.com/thebrotherswisp> > <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> > ------------------------------ > *From: *"Tom Beecher" <beec...@beecher.cc> > *To: *"Mike Hammett" <na...@ics-il.net> > *Cc: *"Mel Beckman" <m...@beckman.org>, "NANOG" <nanog@nanog.org> > *Sent: *Friday, January 6, 2023 9:16:19 AM > > *Subject: *Re: SDN Internet Router (sir) > > Thanks for this example. > > It sounds like you are describing egress peer engineering, but kinda in > reverse. > > In 'traditional' EPE, the routers have all the routes, and you are using > the external controller to perform the performance tests that matter to > you, and signal the network where to take the traffic based on those tests. > > It seems like you want to do the same thing , but instead of having the > controller signal the network where to carry bits, you want the controller > to signal the networks what routes are present, and direct the bits that > way. > > Do I have this right? > > On Thu, Jan 5, 2023 at 4:12 PM Mike Hammett <na...@ics-il.net> wrote: > >> I hesitated to get too specific in examples because someone is going to >> drag the conversation into the weeds. >> >> Let's take the the Dallas - New Orleans - Atlanta example where I have a >> connection from New Orleans to Dallas and a connection from New Orleans to >> Atlanta. >> >> Let's say I peer with Netflix in both markets. Netflix chooses to serve >> me out of Atlanta, for whatever reason. Say my default route sends my >> traffic to Dallas. That's not where Netflix wanted it, so now I have to go >> from Dallas to Atlanta, whether that's my circuit or across the public >> Internet. Potentially, it's on MPLS and it rides back through the New >> Orleans router to get back to Atlanta. That's a long trip when I already >> had a better path, the less-than-full-fib router just didn't know about it. >> Given that Netflix is a sizable amount of traffic in an eyeball ISP, that's >> a lot of traffic to be going the wrong way. If the website for Viktor's >> Arctic Plunge in Siberia was hosted in Atlanta, I wouldn't give two craps >> that the traffic went the wrong way because A), I'll probably never go >> there and B) when someone does, it won't be meaningfully enough traffic to >> accommodate. >> >> Someone's going to tell me to put a full-table router in New Orleans. >> Maybe I should. Okay, so maybe I have a POP in Ashford, Alabama. It has >> transport to New Orleans and Atlanta. There aren't enough grains of sugar >> in Ashford, Alabama to justify a current-generation, full table router. Now >> I'm even closer to Atlanta, but default may point to New Orleans. >> >> >> >> ----- >> Mike Hammett >> Intelligent Computing Solutions <http://www.ics-il.com/> >> <https://www.facebook.com/ICSIL> >> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> >> <https://www.linkedin.com/company/intelligent-computing-solutions> >> <https://twitter.com/ICSIL> >> Midwest Internet Exchange <http://www.midwest-ix.com/> >> <https://www.facebook.com/mdwestix> >> <https://www.linkedin.com/company/midwest-internet-exchange> >> <https://twitter.com/mdwestix> >> The Brothers WISP <http://www.thebrotherswisp.com/> >> <https://www.facebook.com/thebrotherswisp> >> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> >> ------------------------------ >> *From: *"Mel Beckman" <m...@beckman.org> >> *To: *"Mike Hammett" <na...@ics-il.net> >> *Cc: *"Joe Maimon" <jmai...@jmaimon.com>, "NANOG" <nanog@nanog.org> >> *Sent: *Thursday, January 5, 2023 2:54:27 PM >> *Subject: *Re: SDN Internet Router (sir) >> >> Mike, >> >> I’m not sure I understand what you mean by “suboptimal“ routing. Even >> though the Internet uses AS path length for routing, many of those path >> lengths are bogus, and don’t really represent any kind of path performance >> value. For example, a single AS might hide many hops in an MPLS network as >> a single hop, obscuring asymmetric routing and other uglies. Prepending >> also occurs when destinations are trying to enforce their own engineering >> policies, which often conflict with yours or mine. >> >> So what do you mean by “suboptimal“? Are you thinking that the “best” >> path in BGP tables actually meant you were getting a performance benefit? >> Because that’s definitely not the case in today’s Internet. Were were you >> thinking that you would be going along less congested paths? That’s really >> at the mercy of the traffic engineering of backbone providers over which we >> have no control. >> >> I generally populate local router FIBs to merel choose an exit point for >> purposes of load balancing, and nothing more. >> >> -mel >> >> On Jan 5, 2023, at 12:38 PM, Mike Hammett <na...@ics-il.net> wrote: >> >> >> I guess I wasn't around for those days. >> >> As far as running out, again, assuming the tooling works correctly, I'd >> think to target fewer routes than you could hold. Maybe 1k routes is all >> one would need to get a significant percent of the traffic. A lot of room >> to mess up if you can hold 100k, 500k routes. >> >> >> >> ----- >> Mike Hammett >> Intelligent Computing Solutions <http://www.ics-il.com/> >> <https://www.facebook.com/ICSIL> >> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> >> <https://www.linkedin.com/company/intelligent-computing-solutions> >> <https://twitter.com/ICSIL> >> Midwest Internet Exchange <http://www.midwest-ix.com/> >> <https://www.facebook.com/mdwestix> >> <https://www.linkedin.com/company/midwest-internet-exchange> >> <https://twitter.com/mdwestix> >> The Brothers WISP <http://www.thebrotherswisp.com/> >> <https://www.facebook.com/thebrotherswisp> >> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> >> ------------------------------ >> *From: *"Joe Maimon" <jmai...@jmaimon.com> >> *To: *"Mike Hammett" <na...@ics-il.net>, "Christopher Morrow" < >> morrowc.li...@gmail.com> >> *Cc: *"NANOG" <nanog@nanog.org> >> *Sent: *Thursday, January 5, 2023 2:30:40 PM >> *Subject: *Re: SDN Internet Router (sir) >> >> >> >> Mike Hammett wrote: >> > I'm not concerned with which technology or buzzword gets the job done, >> > only that the job is done. >> > >> > >> > >> > Looking briefly at the couple of things out there, they're evaluating >> > the top X prefixes in terms of traffic reported by s-flow, where X is >> > the number I define, and those get pushed into the FIB. One >> > recalculates every hour, one does so more quickly. How much is >> > appropriate? I'm not sure. I can't imagine it would *NEED* to be done >> > all of that often, given the traffic/prefix density an eyeball network >> > will have. Default routes carry the rest. Default routes could be >> > handled outside of this process, such that if this process fails, you >> > just get some sub-optimal routing until repaired. Maybe it doesn't >> > filter properly and sends a bunch of routes. Then just have a prefix >> > limit set on the box. Maybe it sends the wrong prefixes. No harm, no >> > foul. If you're routing sub-optimally internally, when it does hit a >> > real router with a full FIB, it gets handled appropriately. >> >> Unless it loops. >> >> The rest sounds nice. But flow caching got a bad rap back in the early >> worm days. But thats because the situation was a little worse back then. >> Cache the wrong routes or run out of cache, router dies. So long as >> thats not the case automating optimization is an extremely valuable goal. >> >> > >> > >> > I would just be looking for solutions that influence what's in the FIB >> > and let the rest of the router work as the rest of the router would. >> >> The problem comes when the router wont work at all without the FIB >> routes, like in the olden days. >> > >> > >> > >> > ----- >> > Mike Hammett >> > Intelligent Computing Solutions <http://www.ics-il.com/> >> > <https://www.facebook.com/ICSIL>< >> https://plus.google.com/+IntelligentComputingSolutionsDeKalb>< >> https://www.linkedin.com/company/intelligent-computing-solutions>< >> https://twitter.com/ICSIL> >> > Midwest Internet Exchange <http://www.midwest-ix.com/> >> > <https://www.facebook.com/mdwestix>< >> https://www.linkedin.com/company/midwest-internet-exchange>< >> https://twitter.com/mdwestix> >> > The Brothers WISP <http://www.thebrotherswisp.com/> >> > <https://www.facebook.com/thebrotherswisp>< >> https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> >> > ------------------------------------------------------------------------ >> > *From: *"Christopher Morrow" <morrowc.li...@gmail.com> >> > *To: *"Mike Hammett" <na...@ics-il.net> >> > *Cc: *"Tom Beecher" <beec...@beecher.cc>, "NANOG" <nanog@nanog.org> >> > *Sent: *Thursday, January 5, 2023 12:27:08 PM >> > *Subject: *Re: SDN Internet Router (sir) >> > >> > >> > >> > On Thu, Jan 5, 2023 at 11:18 AM Mike Hammett <na...@ics-il.net >> > <mailto:na...@ics-il.net>> wrote: >> > >> > Initially, my thought was to use community filtering to push just >> > IXes, customers, and defaults throughout the network, but that's >> > obviously still sub-optimal. >> > >> > I'd be surprised if a last mile network had a ton of traffic going >> > to any more than a few hundred prefixes. >> > >> > >> > I think in a low-fib box at the edge of your network your choices are: >> > "the easy choice, get default, follow that" >> > >> > "send some limited set of prefixes to the device, and default, so >> > you MAY choose better for the initial hop away" >> > >> > you certainly can do the second with communities, or route-filters >> > (prefix-list) on the senders, or.... >> > you can choose what prefixes make the cut (get the community(ies)) >> > based on traffic volumes or expected destination locality: >> > "do not go east to go west!" >> > >> > these things will introduce toil and SOME suboptimal routing in some >> > instances... perhaps it's better than per flow choosing left/right >> > though and the support calls related to that choice. >> > >> > In your NOLA / DFW / ATL example it's totally possible that the >> > networks in question do something like: >> > "low fib box in tier-2 city (NOLA), dfz capable/core devices in >> > tier-1 city (DFW/ATL), and send default from left/right to NOLA" >> > >> > Could they send more prefixes than default? sure... do they want to >> > deal with the toil that induces? (probably not says your example). >> > >> > SDN isn't really an answer to this, though.. I don't think. Unless you >> > envision that to lower the toil ? >> > >> >> >> >> >
