RE: Firewall and DMZ topology

["Depp, Dennis M." <deppdm () ornl gov>]

First in order to increase security Firewall1 should not be the same as
Firewall2.  Even if they are the same, rules will be different on each
of the firewall.  Different rules means different vulnerabilities.
Finally Intrusion detection should be more sensative on the inside of
the outer firewall.  This enhanced sensativity should alert you that
someone is attempting to compromize the inner firewall.

Dennis

PS I seriously doubt if two firewalls have the same configuration if one
is an internal and one is an external firewall.  For example, on the
external firewall I will allow HTTP request to various Web servers in
the DMZ.  The internal firewall should not allow any internet user to
access a web server.

 

> -----Original Message-----
> From: Daniel B. Cid [mailto:danielcid () yahoo com br] 
> Sent: Tuesday, June 10, 2003 2:47 PM
> To: Zach Crowell
> Cc: security-basics () securityfocus com
>
> I think similar to you. In most companies all the firewalls are the
> same(same OS, same version and same configuration).. If someone is
> able to crack the firewall 1, will be able to crack the 
> firewall 2 and 3
> ..
>
> []`s
>
> Daniel B. Cid
>
> > On Tue, 2003-06-10 at 13:41, Zach Crowell wrote:
> >
> >
> > Erik Vincent wrote:
> > > I think there is a major difference between:
> > >
> > >               1:    internet --> Outer Firewall --> DMZ --> Inner 
> > > Firewall --> LAN
> > >                            If your Outer Firewall is 
> crack, only the DMZ 
> > > computer will be unprotected
> > >                             but the LAN portion still protected.
> >
> > Under what conditions would these firewalls be configured any 
> > differently from a vulnerability-assessment view point?  i.e., if 
> > someone was able to crack the outer firewall, is it not likely they 
> > would crack the inner firewall as well?
> >
> > Zach
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>
>
>
> --------------------------------------------------------------
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> Evaluating SSL VPNs' Consider NEOTERIS, chosen as leader by 
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> The Gartner Group just put Neoteris in the top of its Magic Quadrant,
> while InStat has confirmed Neoteris as the leader in marketshare.
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---------------------------------------------------------------------------
Evaluating SSL VPNs' Consider NEOTERIS, chosen as leader by top analysts!
The Gartner Group just put Neoteris in the top of its Magic Quadrant,
while InStat has confirmed Neoteris as the leader in marketshare.

Find out why, and see how you can get plug-n-play secure remote access in
about an hour, with no client, server changes, or ongoing maintenance.

Visit us at: http://www.neoteris.com/promos/sf-6-9.htm
----------------------------------------------------------------------------