Re: V4 via V6 and IGP routing protocols

[Dave Taht <dave.taht () gmail com>]

I'm actually not here to start a debate... happy to learn that the v4
over v6 feature I'm
playing with actually exists in another protocol, mainly. I'm
critically dependent on
source specific routing, also, so I am hoping there's an isis or ospf
that can do
what I need, or now that I have more routers with enough memory, switch back
to an ibgp.

Is there a lightweight bgp client worth fiddling with? gobgp looked
interesting. Presently
I run bird in some places....

On Sun, Apr 3, 2022 at 6:49 AM Masataka Ohta
<mohta () necom830 hpcl titech ac jp> wrote:
> Dave Taht wrote:
>
> > Periodically I still do some work on routing protocols. 12? years ago I had kind
> > of given up on ospf and isis, and picked the babel protocol as an IGP
> > for meshy networks because I felt link-state had gone as far as it
> > could and somehow unifying BGP DV with an IGP that was also DV
> > (distance vector) seemed like a path forward.
>
> As DV depends other routers to choose the best path from
> several candidates updated asynchronously, which means
> it is against the E2E principle and decisions by other
> routers are delayed a lot to wait all the candidates
> are updated, it is hopeless.

I like to think babel solved most of the problems that RIP had, and
while an optimal state is slow to arrive in babel, a working state is
immediate, it's loop free, and it had a rtt metric.

> OTOH, LS only allows routers distribute the current most link
> states instantaneously and let end systems of individual
> routers compute the best path, LS converges quickly.

Ages ago, I'd written a tool to stress out various igps in a scenario where lots
of routes were coming and going, called rtod. It pretty much broke all the
daemons and protocols I'd had available to me at fairly low levels of churn.

https://github.com/dtaht/rtod

> BGP is DV because there is no way to describe policies of
> various domains and, even if it were possible, most, if
> not all, domains do not want to publish their policies
> in full detail.

yes, and for smaller networks that are interconnecting, bgp can be
too heavyweight also.

> > My question for this list is basically, has anyone noticed or fiddled
> > with babel?
>
> No.
>
>                                                 Masataka Ohta



-- 
I tried to build a better future, a few times:
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Dave Täht CEO, TekLibre, LLC