SDN Internet Router (sir)

Thu Jan 5 20:22:22 UTC 2023

Lots of 1M tcam fib limits in older gear.......

So yeah, its the same problem, bigger numbers and still not solved in 
any sort of non-painful or expensive way.

I think Ill explore the google path and paper on it again.

Joe

Mike Hammett wrote:
> Then please bless the world with the right way.
>
> You acknowledge that not every router in a network needs to be fully 
> DFZ capable, but then crap on my desire to have more than a default 
> route in one.
>
>
>
> -----
> 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" <beecher at beecher.cc>
> *To: *"Mike Hammett" <nanog at ics-il.net>
> *Cc: *"Mel Beckman" <mel at beckman.org>, "NANOG" <nanog at nanog.org>
> *Sent: *Thursday, January 5, 2023 9:55:38 AM
> *Subject: *Re: SDN Internet Router (sir)
>
>     "The right tool for the job" gets into a religious argument in
>     assuming that one's way to do the job is the only reasonable way
>     to do the job
>
>
> I disagree that it's religious. I completely agree there are locations 
> in networks that having full DFZ capable routers doesn't make 
> technical or economic sense. But there have long been different 
> products for those different use cases.
>
> To perhaps explain my viewpoint better,(and perhaps I didn't properly 
> comprehend the problem you're aiming to solve) :
>
> If you are trying to use SDN stuff to shuffle routes on and off a box 
> because you have the wrong sized routers in place, then I would argue 
> you're doing it wrong.
>
> If you are trying to use SDN stuff to (as Christopher mentioned) make 
> decisions that are not strictly LPM, and the equipment you have cannot 
> do that, then that's different and entirely reasonable.
>
> If the second use case is more of what you were asking, then I 
> apologize for misunderstanding.
>
>
> On Thu, Jan 5, 2023 at 9:57 AM Mike Hammett <nanog at ics-il.net 
> <mailto:nanog at ics-il.net>> wrote:
>
>     "The right tool for the job" gets into a religious argument in
>     assuming that one's way to do the job is the only reasonable way
>     to do the job.
>
>     Large networks historically have a very poor (IMO) model of
>     gigantic iron in a few locations, which results in sub-optimal
>     routing for the rest of their network between those large POPs.
>     I've heard time and time again that someone buying service from a
>     major network in say New Orleans has a first hop of Dallas or
>     Atlanta. I agree that full-route capable routers need to be in the
>     large, central locations, but it isn't cost effective to have them
>     at every POP, especially if you're a last-mile provider.
>
>     I'd go into more examples of where it doesn't make sense to have
>     full-route routers everywhere, but I'm afraid that the Internet
>     would then focus on the examples instead of the core idea of
>     intelligently putting routes into the FIBs of low-FIB routers
>     throughout my network.
>
>
>
>     -----
>     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" <beecher at beecher.cc <mailto:beecher at beecher.cc>>
>     *To: *"Mike Hammett" <nanog at ics-il.net <mailto:nanog at ics-il.net>>
>     *Cc: *"Mel Beckman" <mel at beckman.org <mailto:mel at beckman.org>>,
>     "NANOG" <nanog at nanog.org <mailto:nanog at nanog.org>>
>     *Sent: *Wednesday, January 4, 2023 7:36:58 AM
>     *Subject: *Re: SDN Internet Router (sir)
>
>     Disagree that it’s a line in the sand. It’s use the right tool for
>     the job.
>
>     If a device is low FIB, it’s that way for a reason. There are
>     plenty of ways to massage that with policy and software, depending
>     on capabilities , but at the end of the day, trying to sort 10
>     pounds of shit to store in a 5 pound bag is eventually going to
>     end up the same way.
>
>     On Tue, Jan 3, 2023 at 13:18 Mike Hammett <nanog at ics-il.net
>     <mailto:nanog at ics-il.net>> wrote:
>
>         There are likely more networks with 10 gigabit or less total
>         external capacity than there are with more.
>
>         Creating imaginary lines in the sand doesn't really help anyone.
>
>
>
>
>         -----
>         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" <mel at beckman.org <mailto:mel at beckman.org>>
>         *To: *"Mike Hammett" <nanog at ics-il.net <mailto:nanog at ics-il.net>>
>         *Cc: *"NANOG" <nanog at nanog.org <mailto:nanog at nanog.org>>
>         *Sent: *Tuesday, January 3, 2023 10:57:34 AM
>         *Subject: *Re: SDN Internet Router (sir)
>
>         It’s not a problem, due to cheap, plentiful high-speed memory
>         and rapid prefix search silicon in backbone routers. The
>         entire Internet routing table consumes at most a few gigabytes
>         when fully structured (and only a few hundred Mbytes stored
>         flat). That’s less memory than your average laptop sports.
>
>
>         Even in the worst case scenario, where every network decides
>         to announce only its most specific prefixes, the BGP backbone
>         would temporarily enter an oscillating state that generates a
>         large number of routing updates into the inter-domain routing
>         space. In this case, BGP route damping will quickly suppress
>         the crazies while the backbone stabilizes.
>
>
>         Small routers should not be taking full tables, since there is
>         no point to them being in the default free zone. For large
>         routers, neither memory nor CPU speed are an issue. High-speed
>         routers operating in the default-free zone have a critical
>         path in the forwarding decision for each packet: it needs to
>         take less than the inter-packet arrival time for minimum-sized
>         IP packets.
>
>
>         This is easy to achieve with today’s hardware. A router line
>         card with an aggregate line rate across all of its
>         point-to-point interfaces of 10Tbps (readily available in
>         today’s gear) can process packets with just a handful of
>         cycles in the FIB Ternary Content Addressable Memory (TCAM)
>         using ASIC-assisted lookups. TCAM is the most expensive
>         component you’re paying for in such a router. It’s not cheap,
>         but backbone routers don’t need to be cheap. They just need to
>         not be memory-constrained.
>
>
>         -mel via cell
>
>             On Jan 3, 2023, at 7:47 AM, Mike Hammett <nanog at ics-il.net
>             <mailto:nanog at ics-il.net>> wrote:
>
>             
>             https://github.com/dbarrosop/sir
>
>             I came across this over the weekend. Given that the
>             project was abandoned six years ago, are there any other
>             efforts with a similar goal (more intelligently placing
>             routes into FIBs of low-FIB capacity devices?
>
>
>
>             -----
>             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>
>
>
>
>