Bj, normally I find myself agreeing with you comments but not in this case.
A router is not a firewall. A router has routing tables to manage where
packets are sent. These are dynamic tables (one used to have to enter IP
addresses manually) but such tables in no way constitute a firewall. The
intelligence that allows routers to dynamically manage addresses also allows
additional features to be added. One of these is NAT (Network Address
Translation) which acts something like a proxy server. The NAT connects
private addresses (usually the reserved 192.168.xxx.xxx range) to the
internet through a public IP (usually assigned by your ISP). That's all it
does. It "hides" your network but not very effectively. It is most
emphatically not a firewall. 

Linksys, D-Link, and Netgear (popular home routers) also include some
elementary firewall features in their routers. Some of these features will
drop packets with the private address which originate outside the network
(such addresses are forged since they should be dropped by public routers by
default). Other features allow for the creation of a DMZ to manage a public
web server. And some even allow stateful inspections of packets (which
determines that your network initiated the session not the other way
around). These are sometimes running by default and sometimes have to
initiated by you, the end user.

And even with all these features added, an application firewall like Zone
Alarm or Tiny is advisable on all machines, especially any servers, in your
home network. It is possible to forge packets to fake a session by an
application. This kind of software firewall is designed to prevent that
forgery by being sure that you initiated the application session. It also
watches that things like Trojans don't communicate out to their masters.
These firewalls protect an individual machine while router based firewalls
protect the network. 

And none of this has anything at all to do with email security. That's a
separate but related need.

The best advice is protection in depth and there is no such thing as too
much depth.

drew

-----Original Message-----
From: PlainWeb Design [mailto:[EMAIL PROTECTED]
Sent: Saturday, March 01, 2003 5:58 PM
To: [EMAIL PROTECTED]
Subject: [wdvltalk] Re: How Firewall?


 --- Zhao <[EMAIL PROTECTED]> wrote: 
> 
>   For a small home network, what firewall is
> suitable to use?

You don't need to run a firewall on the PCs to protect
them if you are connecting to the Internet through a
router like the Linksys.  That acts as a physical
firewall between your network and the internet.  There
are more expensive routers that have their own
firewall software if you need to do very complicated
stuff like having certain ports blocked and others
open, or running a public Web server from your
network.  If you are going to avoid using a router and
just do connection sharing from one of the PCs, then
you need a good software firewall like ZoneAlarm which
is free and also very good.

Bj

=====
Sunshine Graphics / PlainWeb Design
Website Design, Programming and Hosting
http://www.sungraph.co.uk
http://www.plainweb.co.uk

__________________________________________________
Do You Yahoo!?
Everything you'll ever need on one web page
from News and Sport to Email and Music Charts
http://uk.my.yahoo.com

____ * The WDVL Discussion List from WDVL.COM * ____
To Join wdvltalk, Send An Email To: mailto:[EMAIL PROTECTED] 
       Send Your Posts To: [EMAIL PROTECTED]
To change subscription settings to the wdvltalk digest version:
    http://wdvl.internet.com/WDVL/Forum/#sub

________________  http://www.wdvl.com  _______________________

You are currently subscribed to wdvltalk as: [EMAIL PROTECTED]
To unsubscribe send a blank email to %%email.unsub%%

____ � The WDVL Discussion List from WDVL.COM � ____
To Join wdvltalk, Send An Email To: mailto:[EMAIL PROTECTED] 
       Send Your Posts To: [EMAIL PROTECTED]
To change subscription settings to the wdvltalk digest version:
    http://wdvl.internet.com/WDVL/Forum/#sub

________________  http://www.wdvl.com  _______________________

You are currently subscribed to wdvltalk as: [EMAIL PROTECTED]
To unsubscribe send a blank email to [EMAIL PROTECTED]

Reply via email to