should TCPs do MTU black hole detection?

Dave Morton dmorton at
Fri Nov 19 20:52:55 UTC 1999

foxRandy Bush wrote:
> >> I'm wondering whether the ISP community has a clear preference for either
> >> yes-do-detection or no-we-want-the-problems-fixed.
> >> Comments appreciated.
> > I think that most ISP's would prefer that problems were fixed.
> the choice seems
>   o when it breaks, the noc gets the call, debugs it, and it gets fixed

Well Randy, ideally yes but reality sucks as we know. We had this crap as
well and tried to get folks to fix it - important sites just don't care and
yes, we are usually talking broken web stuff here. Hard to tell their
ISP to get them to fix it. I am asking myself if we can nuke it elsewhere,
nothing obvious right off ?
>   o when it breaks, the software does successive guesswork back-offs until
>     it makes it through.  the performance sucks big-time, the customer
>     thinks the isp is at fault, but the noc does not get called and the
>     real problem never gets fixed.

Agreed. Regardless of what I mention above, nuke em, i.e. fix.
> randy

More information about the NANOG mailing list