Long keepidle time

[Mike Silbersack]

On Fri, 11 Aug 2006, Simon Walton wrote:

>  Is there any reason why the default initial timeout for keep alive
> packets needs to be as long as two hours? This period causes the dynamic 
> rules in my firewall filter to timeout.
>
>  Is there a major objection to reducing the default idle time to
> say 3 to 5 minutes?
>
> Simon Walton

On reason behind a 2 hour keepalive is so that you don't have a 2 minute 
network outage that causes all your connections to timeout.

Of course, as you point out, in the modern age of firewalls, more frequent 
keepalives can be a good thing.

I don't forsee us changing FreeBSD's default keepalive setting, but you're 
more than welcome to change the setting on your own system.

Also note that ipfw2 sends keepalive packets on its own, maybe you could 
switch to it and/or add that functionality to your favorite firewall 
package. :)

Mike "Silby" Silbersack