Re: help w/ network design



On Wed, 25 Jul 2007, in the Usenet newsgroup comp.os.linux.networking, in
article <2007072522402775249-enderwigginandrew@gmailcom>, Ender wrote:

I'm trying to design a really secure network

"The best firewall is two inches of air."

which has both wireless and ethernet and I was wondering if there is
a common standard type of network setup I should use.

Not really - it depends on what services you want to offer to who, and
what risks you are guarding against. For a "home" or small business
type of setup, see the Home-Network-mini-HOWTO and the
Networking-Overview-HOWTO from the LDP. For more details, see the Linux
Network Administrator's Guide (nag2). Depending on your distribution,
these may be installed in /usr/share/doc or similar.

I was thinking about something like this ...

Internet --> Firewall/Router(1) --> Access Point --> Firewall/Router(2)
--> Computers

That's one possible layout

The questions I'm wondering about are ...

1) Is it common to put 2 firewalls in a network?

There's a firewall at the corporate perimeter - another at the division
perimeter - still another at the facility perimeter, and a final one
at the department level. That's four. My wife works at a different
company, and they have only a perimeter firewall with all of their
"public" servers (web, mail, DNS, etc. for use/access from the world,
AS OPPOSED TO web, mail, DNS, etc. servers meant for internal use only)
hosted by an off-site provider. Pay your money - take your pick.

I did that to put things like the access point and maybe some web
servers in between, kinda like *I think* a DMZ sort of setup

I suspect you'll see more DMZs set as a separate stub off the first
firewall such as

Internet <--> Firewall <--> internal network
^
|
v
DMZ

The firewall rules are set such that systems _in_ the DMZ can not
initiate connections to the internal net, and only certain hosts
inside can connect to the DMZ hosts for other than very limited
services. There can also be _additional_ firewalls on the internal
network - that depends on what's in there, and what you see as your
threat model.

2) Is this correct to place the Access Point between these two
firewalls?

That depends on your threat model - what are you trying to protect,
from who? Only you can answer that question.

My thinking here is that since I want all the data on my ethernet to
be secure,

From who?

then the access point should not be on the inside

Are you worried about packet sniffers? Most modern networks are
switched, and your bad guy would have to be able to subvert the switch
in order to hear anything except broadcast traffic.

and users should come through the same front door as anyone else
(along w/ the normal authentication and authorization on the wifi).

Depends on the threat model. The networks I'm most familiar with
have remote access for employees on a separate DMZ from the one
containing public servers.

Old guy
.



Relevant Pages

  • Ang: RE: Firewall and DMZ topology
    ... Network Engineer ... Subject: Firewall and DMZ topology ... > The Gartner Group just put Neoteris in the top of its Magic Quadrant, ...
    (Security-Basics)
  • Re: Lets talk about firewalls - what do we as a group think a firewall should be/have?
    ... part of the same network as the LAN. ... Each interface of a firewall should be distinct from ... interfaces, so a "DMZ interface" is not a requirement. ...
    (comp.security.firewalls)
  • Re: Firewall and DMZ topology
    ... > network, Windows and Linux. ... > laptop used as a simple firewall setup. ... > machine and placing it in a DMZ. ... > internal network, one for the DMZ and one for the Internet. ...
    (Security-Basics)
  • RE: Basic Network Configuration
    ... > IMHO the second rule is void, since no traffic should bypass the DMZ. ... that originates from your internal network. ... There is no point in implementing the same firewall ... >> really achieve this benefit if the boxes run different OS ...
    (Security-Basics)
  • RE: can ping but not browse
    ... I have stopped the firewall. ... # are safed from all (security) hazards. ... firewall/bastion host to the internet ... # internet and to an internal network, ...
    (Fedora)