Re: [Idr] draft-head-idr-bgp-ls-isis-fr-01 - WG adoption call (6/6 to 6/20)

[Tony Przygienda <[e-mail]>]

On Wed, Jun 8, 2022 at 10:41 PM Robert Raszuk <[e-mail]> wrote:

> ...
>
> All 100% transparent to customers and they do not care if BGP parses each
> IGP TLV bit or not.
>
>
so for sake of completeness and to be fair to BGP-LS as it stands since it
seems this "pinata" thread got a bit too one-sided ;-) There were more good
arguments than the BGP is inter-AS ...

Writing a good IGP parser is NOT trivial (especially ISIS) and then you
still have to stitch e'thing together from all the fragments flying around.
And that parser needs be maintained with IGP changes as well. And it's not
easy to get your hands on really good maintainable IGP parsers in open
source properly chopped off the main protocol implementation on top (unless
you enlighten me). And you have to keep up with flooding possibly &
tie-breaking and so on. For large operators at scale and so on arguably  a
viable path, for lots of folks with limited resources BGP-LS is arguably a
much easier thing to consume to monitor some things/get some data.

Also, there seem to be assumptions here that the code MUST be hacked into
BGP. That ain't so, arguably you can architecture independent code that has
read-only access to IGP and builds a projection of it as BGP-LS stuff that
is given to BGP to push out without BGP understanding really how the thing
comes about.

so, 7752 was a trade-off. given how successful it got arguably a viable
trade-off as non-perfect things go ;-)

-- tony