On Fri, 3 May 2002, Tom Eastep wrote:

> 
> No -- the two rules you added had NO EFFECT WHATSOEVER on the outcome. 
> 

To clarify -- since the packet and bytes counts for those two rules were 
zero after your second test, the rules could not have had any possible 
effect.

One other thing -- be very careful when performing back-to-back tests 
using Netfilter-based firewalls. The connection-tracking entries for most 
protocols (TCP being the exception) live on after the connection has been 
terminated. If you establish a similar connection before these tracking 
entries have expired, the entries can be reused (this is especially true 
of protocols that do not make use of ports or that use the same port 
number for source and destination). This can lead you to believe that your 
latest set of rules "worked" when in fact it did not. A "shorewall 
restart" does not clear the tracking table (it can't because there is no 
way way for it to do so).

There has been a lot of grumbling on the Netfilter mailing list about 
the lack of a means for removing connection-tracking entries. Until that 
grumbling results in a change though, caution is advised.

-Tom
-- 
Tom Eastep    \ Shorewall - iptables made easy
AIM: tmeastep  \ http://www.shorewall.net
ICQ: #60745924  \ [EMAIL PROTECTED]


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