[opensource] Router(s) on OSU network may be breaking TCP window scaling

Seth Hall seth at net.ohio-state.edu
Thu Sep 7 11:25:19 EDT 2006

On Sep 6, 2006, at 10:17 PM, Wesley Haines wrote:
> I can access the following sites:
> * www.osu.edu
> * buckeyelink.osu.edu
> * food.osu.edu
> * tp.osu.edu
> I cannot (or have very slow access) to the following sites:
> * www.ureg.ohio-state.edu
> * www-bprc.mps.ohio-state.edu
> * glennschool.osu.edu

I looked around at the problem briefly and it seems that all of the  
hosts that were not working for you seem to be behind firewalls that  
were sold to departments by a member of our team.  The working ones  
are not behind our firewalls.  It appears that openbsd doesn't deal  
with the tcp window size scaling flag set to 7 under certain  

I'm going to look into it in more detail and hopefully we can get all  
of the firewalls updated to cope with larger tcp window size scaling  
flags soon.  Thanks for the report.


Seth Hall
The Ohio State University
Network Security Engineer
Email: seth at net.ohio-state.edu
Phone: 614-292-9721

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