[NANOG] Microsoft.com PMTUD black hole?

Wed May 7 01:18:08 UTC 2008

Tomas L. Byrnes wrote:

> Interestingly, Windows XP, Sp3, released today, describes changes in
> PMTUD behavior.
> 
> Black Hole Router detection is now on by default:

As I pointed out in my post earlier today timestamped at 2:29PM, I was 
using an XP SP3 host to perform my tests with, and it made no 
difference.  I also used BBR's DrTCP application to make sure that black 
hole router detection was, in fact, enabled on my XP box before 
commencing my packet captures.

I cannot explain why it made no difference, but at the same time I don't 
know enough about how WinNT's black hole router detection works to begin 
speculating at this point.  I do plan on looking into it, however.

-- 
Nathan Anderson
First Step Internet, LLC
nathana at fsr.com