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Date:      Mon, 26 Feb 1996 21:44:14 +0100
From:      Poul-Henning Kamp <phk@critter.tfs.com>
To:        Joe Greco <jgreco@brasil.moneng.mei.com>
Cc:        imb@scgt.oz.au, stable@freebsd.org, current@freebsd.org
Subject:   Re: -stable hangs at boot (fwd) 
Message-ID:  <12319.825367454@critter.tfs.com>
In-Reply-To: Your message of "Mon, 26 Feb 1996 12:12:14 CST." <199602261812.MAA15629@brasil.moneng.mei.com> 

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> > 	1. is the present packet & byte count per rule enough ?
> 
> Adequate for what I am doing.  I am worried, however, about the potential
> for byte count rollover, I don't know if it's a 32-bit or 64-bit quantity.
> I would like to be able to leave a "cumulative" counter running...
yes, I would really love to make them 64 instead of 32, but right now
the structure is 64bytes, and I'd hate to increase it to 128 :-(

> > 	2. are you going to miss "bidir" much ?
> 
> !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
> 
> Owwwww.  See below.  I use it a lot :-(

I thought so, it's just that we need a lot of special code to do it,
and I think it is kind of messy anyway...

> > 	3. do we need a precise, atomic "read & reset" operation ?
> 
> I am sampling hourly and my belief is that it takes less than a second to
> do, and a 1/3600 error is acceptable to me.  However, for those folks who
> might be making more practical measurements (i.e. measuring NNTP traffic to
> various sites every 5 seconds), a read and reset operation would be great.
Ok, not bad to do.

> So the answer is "Yes but not for me right now".
OK, will think.

> > 	4. anything else ?
> 
> Okay, here's a problem I've been wanting to solve.  I have a rule:
> 
> ipfw adda bidirectional all from 0/0 to 0/0 via 204.95.219.1
> 
> that I use to give me a really rough guess about my T1 loading.
> 
> The problem is, I handle multiple CIDR blocks.  If I had a single CIDR
> block, I could do
CIDR ?   Uhm,  Canned Indian Doughnut Rolls ?  no, hmm, I guess,
Contiguous Internet something ?

> *know* the interface I want to watch!  What I would LIKE to see:
> 
> # Outbound traffic
> ipfw adda all from 0/0 to 0/0 sentvia 204.95.219.1
> 
> # Inbound traffic
> ipfw adda all from 0/0 to 0/0 rcvdvia 204.95.219.1

Check out the strawman I just emailed, and actually you can do that in
the present code:

	ipfw add count from any to any in via 204.95.219.1
	ipfw add count from any to any out via 204.95.219.1

:-)

> In other words, I would like the ability to specify the direction the packet
> was travelling on the "via" interface...  it would pretty much kill the main
> use for "bidir" that I have, and give me a much more accurate idea of what's
> going on.
got it :-)

> How about IPFW issues?  I know you didn't ask but as long as you're in the
> code, maybe some of these issues are of interest to you too.
> 
> Is it possible to fill in the byte/packets dropped by a particular filter?
> (the fields in ipfw -s -a -n l are always 0)
It is :-)  I can see that I'm about two days ahead of you still :-)

> Last time I checked (2.0.5R), the "reject" keyword didn't produce a
> ICMP HOST_UNREACHABLE.
It only does in some cases, I'll have to check it out a bit.  It's a mine-
field, so I'm very careful.

> Last time I checked (2.0.5R), the "log" (also l before reject/deny) panicked
> the box.
doesn't now.

> I can't match specific icmp messages - i.e. I allow ping in both directions
> or I break ping in both directions.  That bites.
Hmmm, noted.

> The "syn" protocol (to firewall TCP connections being opened in a direction)
> didn't seem to work.  Maybe it was just me.
It does now, better than ever I think.

Sounds like you should take a peek on the ipfw.8 manpage of -stable or 
-current, you may just like it :-)

> Obviously I know you can't possibly address all of the above, but these are
try me :-)
> all issues that I believe lower the value of IPFW.  Solving some/all of
> these problems would go a long way towards making IPFW look much more like a 
> professional firewalling product and not just something hacked together.
> (not to mention increase the utility greatly!)

I'm looking forward to your comments on the strawman I sent out!

--
Poul-Henning Kamp           | phk@FreeBSD.ORG       FreeBSD Core-team.
http://www.freebsd.org/~phk | phk@login.dknet.dk    Private mailbox.
whois: [PHK]                | phk@ref.tfs.com       TRW Financial Systems, Inc.
Future will arrive by its own means, progress not so.



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