Gentoo Archives: gentoo-user

From: John Jolet <john@×××××.net>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Re: internet/lan access control
Date: Thu, 27 Oct 2005 13:41:48
Message-Id: 200510270838.27036.john@jolet.net
In Reply to: [gentoo-user] Re: internet/lan access control by James
1 On Thursday 27 October 2005 07:53, James wrote:
2 > Well, there are lot's of ways to 'skin the cat' here.
3 >
4 > Here's a good overview of some of the tools tools that you could use:
5 > http://www.gentoo.org/doc/en/security/
6 > security-handbook.xml?part=1&chap=12#doc_chap1
7 > The section on Squid would apply particularly to you.
8 >
9 > <snip>
10 > In this case, my policy states:
11 > * Surfing (HTTP/HTTPS) is allowed during work hours (mon-fri 8-17 and
12 > sat 8-13), but if employees are here late they should work, not surf
13 > * Downloading files is not allowed (.exe, .com, .arj, .zip, .asf, .avi,
14 > .mpg, .mpeg, etc)
15 > * We do not like banners, so they are filtered and replaced with a
16 > transparent gif (this is where you get creative!).
17 > * All other connections to and from the Internet are denied.
18 > <snip>
19 would it be possible to see an example of the squid config that does this?
20 >
21 > You'll most likely need a good firewall and an Aplication Level Gateway
22 > (ALG) to get roboust control of your networks.
23 >
24 > On the firewall side of things, I have taken the 'painful' but superior
25 > route to learning/testing/reading/test/reading_some_more/testing.....
26 > to use raw ipfilter/netfilter to achieve fine grain control of networks.
27 >
28 > Others will recommend you use a 'canned firewall' technology, such as
29 > shorewall, fwbuilder (etc) along with various packages that create
30 > your ALG.
31 >
32 > Learning raw ipfilter/netfilter is a very time consuming process, but,
33 > well worth the effort, in my experience. With the help of this list,
34 > you can achieve robust control over your networks, but, it
35 > does take time. The good thing about investing the time in a linux
36 > setting, is once you have a network management system in place, it's
37 > very straight forward to maintain, you do not have to spend money
38 > or waste time on vendors, and you learn how to *TEST* what you have
39 > to verify it works properly. Using a vendor, makes you subjectively
40 > vulnerable to the vendor's financial goals and technical limitations.
41 > You'll not likely be able to afford a company that has 1/10th the
42 > security expertise, that this list offers for free.
43 >
44 > Regardless of the path you choose, you have to test, modify and test
45 > your network again, with a variety of tools, to ensure robust content
46 > control and sufficient security.
47 >
48 > I'll assume you want the easy, minimal_pain route to controlling your
49 > networks, so I'll let the others pitch easy solutions, that allow
50 > use of software package such as shorewall + squid etc.
51 >
52 > If you want some more links to read about raw ipfilters, just let me know.
53 >
54 > HTH,
55 > James
56
57 --
58 John Jolet
59 Your On-Demand IT Department
60 512-762-0729
61 www.jolet.net
62 john@×××××.net
63 --
64 gentoo-user@g.o mailing list

Replies

Subject Author
[gentoo-user] Re: internet/lan access control James <wireless@×××××××××××.com>