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RE: Protecting Multiple Public IP Workstations
From: "David Gillett" <gillettdavid () fhda edu>
Date: Tue, 2 Mar 2004 12:57:48 -0800

  The right approach is to block everything, and then unblock the ports
you actually need.  This is both more reliable and more cost-effective
than trying to block only "known bad" ports.
  The problem, of course, is that this breaks FTP unless you either (a)
enable all outbound and use PASV mode, or (b) install a stateful, FTP-aware
firewall instead of relying on the router to filter your traffic.  And
in a world of chatty OSes and services and worms and ad-ware, enabling
all outbound is a poor choice....

Dave Gillett

-----Original Message-----
From: Preston, Tony [mailto:Tony.Preston () acs-inc com]
Sent: Tuesday, March 02, 2004 5:32 AM
To: security-basics () securityfocus com
Subject: RE: Protecting Multiple Public IP Workstations


I have a linksys router and have a question...  It has a minimal port
filtering capability.  I block a couple of ports (135-139, 445), and
wondered what would be a suggested list of ports to block 
traffic based on
known virus/trojans.

Tony Preston
Systems Engineer, AS&T Inc.
Division of L3 Corporation
(609) 485-0205 x 181


-----Original Message-----
From: Paul Kurczaba [mailto:paul () myipis com] 
Sent: Friday, February 27, 2004 7:52 PM
To: MATT GIBSON; security-basics () securityfocus com
Subject: Re: Protecting Multiple Public IP Workstations

First of all, it's never a good idea to assign public IP's to 
workstations
on a networked environment (this type of environment is a 
hackers wish come
true). If you are not hosting services on all six IP's, you can buy a
$100-$150 firewall/router at compusa (I would recommend 
Linksys or Netgear).
Most have 4 or 8 ports. If the firewall/router you buy only 
has 4 ports,
also pick up a 4 port switch (it's about $50-$70). If you 
need all 6 IP's
(for hosting HTTP, FTP, SMTP, etc.), you should probably get 
a CheckPoint
FW-1 or a Cisco PIX. Also, if you havn't already bought the 
Win2k server, I
would suggest Server 2003 instead. It takes less than 10 
seconds to boot,
the OS is faster, and more secure than 2000.

just my $0.02

-Paul Kurczaba


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---------------------------------------------------------------------------
Free 30-day trial: firewall with virus/spam protection, URL filtering, VPN,
wireless security

Protect your network against hackers, viruses, spam and other risks with Astaro
Security Linux, the comprehensive security solution that combines six
applications in one software solution for ease of use and lower total cost of
ownership.

Download your free trial at
http://www.securityfocus.com/sponsor/Astaro_security-basics_040301
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