FIN_WAIT_[1,2] and LAST_ACK

[Julian Elischer]

On Mon, 5 Apr 2004, Eli Dart wrote:

> 
> In reply to Brandon Erhart <berhart at ErhartGroup.COM> :
> 
> > Well, I responded to the group that I had taken one of the fellows advice 
> > posting here, and modified the tcp_usrclosed in netinet/tcp_usrreq.c.
> 
> 
> I understand that -- I was trying to discover if you'd come across 
> something that needed a more general fix (see note from Mike 
> Silbersack).  If your application can't wait for whatever the 
> standard timeout is, that's fine -- you've got your fix, and you're 
> good to go.  However, if there is a problem with connections hanging 
> out forever in the process of closing, that something that might be 
> good to look at independently.
> 
> So, do you remember how long the "problem connections" were sticking 
> around in FIN_WAIT_? or LAST_ACK?  Are we talking seconds, minutes, 
> hours, days?
> 
> Thanks,

On the topic of Session shutdown...

 I have noticed an increasing number of machines on the net
are terminating their session (usually the server, but not always)
with a  RESET packet instead of a FIN packet.
In particular it seems that if the machine in question recieves
a FIN packet, and has no more data to send, it replies with
a RESET.

I don't know what kind of machines this is but next time I see it I
guess I'll look at it harder. 

Julian