Re: Linux 2.2.16 through 2.2.18preX TCP hang bug triggered by rsync

[Andi Kleen]

On Wed, Jan 24, 2001 at 11:03:34PM +0300, [e-mail] wrote:
> Hello!
> 
> > I read through the tcpdump, and it seems that Linux completely ignores
> > packets with out-of-window sequence numbers:
> 
> Yes, Linux is __very__ not right doing this. RFC requires to accept
> ACK, URG and RST on any segment adjacent to window, even if window
> is zero.

It's mostly for security to make it more difficult to nuke connections
without knowing the sequence number.

Remember RFC is from a very different internet with much less DoS attacks.

-Andi