Thanks!  That explains it perfectly.

-simon

----- Original Message -----
From: "Michael W. Burden" <[EMAIL PROTECTED]>
To: "Simon Yeo" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Tuesday, July 11, 2000 6:10 AM
Subject: RE: strange log entries


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> This is one of the things that will definitely be in the FAQ
> if it ever gets written  :)
>
> What is happening is that one of the machines on your LAN
> (possibly the DMZ, but more likely the PRO) is connecting to
> a website on the Internet.  The website in question responds
> slowly (either because it is under a heavy load or because of
> a lot of traffic on parts of the Internet between your
> network and the webserver).  By the time that the response
> finally comes back, the machine that requested it has timed
> out, and the GNAT Box is no longer expecting the reply.
> Because the GNAT Box no longer has an entry in the state table
> for the connection, it is treated as an unsolicited connection
> and blocked.
>
>
> The default filter set (at least under 3.0.2 and 3.0.3) includes
> a filter similar to:
>
>   #DEFAULT: Block/nolog stale WWW accesses.
>        Deny   ANY TCP  nolog
>           from "ANY_IP" 80
>             to "ANY_IP" 1024:65535
>
> that prevents "late" replies from generating alarm messages.
>
> Since you started getting the messages at the same time that
> you converted from NAT to IP Passthrough, I'm guessing that
> a filter like this didn't get added to the new configuration.
>
> Mike Burden
> Lynk Systems
> (616)532-4985
> [EMAIL PROTECTED]
>
>
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
> > Simon Yeo
> > Sent: Monday, July 10, 2000 9:04 PM
> > To: [EMAIL PROTECTED]
> > Subject: strange log entries
> >
> >
> > --------------------- Attention -----------------------------
> > Online GNAT Box User Forum is Now Open
> > Click the Register link and sign up today
> > http://www.gnatbox.com/cgi-bin/Ultimate.cgi
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> > -------------------------------------------------------------
> > We recently converted to NAT from IP-passthru, and started getting a
bunch
> > of these log entries:
> >
> > -----------
> >      ALARM NO: 5
> >          DATE: Monday, Jul 10, 2000
> >          TIME: 17:14:11
> >     INTERFACE: EXT (xl0)
> >    ALARM TYPE: Block
> >     IP PACKET: TCP  [a.b.c.d/80]-->[w.x.y.z/33242]  l=1460 f=0x10
> >
> > DETAILED DESCRIPTION:
> > IP packet was rejected.
> > ----------
> >
> > w.x.y.z is the ip-addr of our external interface, and a.b.c.d is
> > some random
> > web site (in most cases).  Why are these seemingly getting
> > blocked?  What's
> > wierder is that none of our users are having any problems surfing the
web.
> >
> > Thanks,
> > -Simon
> >
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