[OmniOS-discuss] WARNING: High TCP connect timeout rate! System (port 80) may be under a SYN flood attack!

[Dale Ghent]

Likely coincidence. Have you managed to catch one of these in the act and inspected netstat and snoop/tcpdump output?

/dale

> On Mar 28, 2017, at 9:43 AM, Bob Friesenhahn <bfriesen at simple.dallas.tx.us> wrote:
> 
> Since updating OmniOS to r151020, I have been seeing many "SYN flood attack!" warnings on the system console.  I never saw these before.
> 
> Has something changed in the TCP/IP stack which now produces these warnings or has my server been co-incidentally targeted for SYN flood attacks and was not targeted before?
> 
> Are other users seeing these warnings?
> 
> I have 45 such alerts posted since Febrary 27 (in the /var/adm/messages* files).
> 
> Bob
> --
> Bob Friesenhahn
> bfriesen at simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
> GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
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