Firewall Configuration Question... Is this possible?

Tim Patterson tim at
Wed Aug 3 00:49:17 CEST 2005

This wasn't meant to cause an outburst of security concerns...  I'm trying
to develop some custom software for a University that will allow remote
access to certain aspects of the firewall.  This is no more of a security
risk than an embedded web server inside a router that is used for

I work for a University...  a .edu in an e-mail address isn't humiliating,
it is an honor.  It's not my fault that a few .edu airheads ruined our rep.

-----Original Message-----
From: netfilter-bounces at
[mailto:netfilter-bounces at] On Behalf Of R. DuFresne
Sent: Tuesday, August 02, 2005 2:04 PM
To: Jan Engelhardt
Cc: netfilter; /dev/rob0
Subject: Re: Firewall Configuration Question... Is this possible?

Hash: SHA1

On Tue, 2 Aug 2005, Jan Engelhardt wrote:

>> doable, but not adised, a firewall should be single purpose, most servers
>> should be single purpose where possible.  But then this is not often the
>> But a firewall certainly should be a single purpose system much like a
>> is, they do similair work anyways.
> Having many servers has two disadvantages: Power consumption and
> administration expense (you gotta install and upgrade each of them).
> A "service split" [for load balance] is not bad, but you can also overdo

security basics 101, servers have their single purpose.  Make monitoring 
for pathces for that specific service for that admin easier, makes for not 
a single point of failure, and is more important for the network choke 
points such as FW's.  Of course, I'm coming at this with a corporate 
perspective, not a little home network.

>> putting a web servers on the firewall makes the firewall and the whole
>> network subject to any issues that the web services now face, plus you
now have
>> to allow naother set of ports/protocols directly to the system and not
> You don't run a webserver with root.

Of course not, but surely you understand once a shell is gotten on a 
system getting root is ussually trivial, especially in nost default 
installs whence evertything and the kitchen sink go in.  Few folks 
actually do minimal installs these days, and many distributions of Linux, 
and I'm guessing a number of the *BSD's are a pain to inimalize.  Same is 
getting to be more and more true of the major vendored unix's as well.

As many have stated, it also depends upon your security posture, and the 
importance of what you are protecting.  No if I recall the admin in 
question that raised the issue had a .edu in their address.  They have 
been most notorious for *not*  doing the right thing and trying to 
"conserve" resources to the extenxt that they tend to be the bain of most 
corporate and hiome user systems/netowrks due to their usser exploiting 
easiliy the weaknesses that tend to be inherent in their design and 
deployment.  Ths my emphasis in this reguard in stating the better 
implimentation.  Now if you really wanna argue further these basics, I'd 
invite you to the firewal wizards list to talk about minimal security 
design implementaions and what does not work in actually trying to secure 
a network.


Ron DuFresne
<doable does not imply best practice>
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