[Ace-users] [ace-users] ACE not detecting connection closing with keepalive enabled

Yan Burman yan_b at tech-mer.com
Tue Dec 4 00:55:47 CST 2007

On Dec 3, 2007, at 9:44 AM, Matthew Gillen wrote:

> Doug's right, it's a linux issue not an ACE issue.

Right.  Also, very importantly, it's not a TCP issue, either.

> That said, you might try using either NetworkManager or ifplugd.  
> Windows by default detects when there's no ethernet cable and  
> disables the interface, thus accelerating network failure messages.  
> Older linux distros don't, so the interface stays "up" even when the  
> plug is pulled. Which way is "right" is debatable, and depends on  
> what you're trying to do (for your case, it looks like you'd prefer  
> the Windows behavior). The two programs I mentioned add the "take  
> the interface down when the cable is unplugged" functionality to  
> linux.

Right.  All of this is below and beyond what TCP covers.

It's also debatable as to whether TCP should detect the loss of the  
network itself.  TCP is very optimistic in regard to network outages,  
preferring to presume that the network will heal itself or the problem  
be routed around, and the segment get through.  An important clue is  
the name of the option itself: it's the "keep alive" option, designed  
to keep a TCP-level session up, not a "detect death" option.

Thanks for the quick reply.

Network interface down does not help me, since I'm connected to a switch
and my link may be up. I'm trying to detect disconnected clients using
keep-alive and it worked quite well until I found the case where it

I will check if this happens without ACE as well.

Yan Burman

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