building a redhat linux firewall – a user experience

Building a RedHat Linux Firewall – A User Experience

USERblueSan FranciscoSession 6306

Abstract

Linux makes an excellent firewall! It's in there! I kept hearing that, so when I needed a firewall to protect my home lan from all the badness on the Internet I started my quest for the ideal linux firewall. I'm now on version three, and not finished yet. Come hear my story, and perhaps take home a few ideas you can use when you connect your home or office to the Internet.

The Speaker

Harold PritchettPatricia Egen Consulting

(706) [email protected]

Disclaimer

Everybody has lawyers:

The ideas and concepts set forth in this presentation are solely those of the respective authors, and not of the companies and or vendors referenced within and these organizations do not endorse, guarantee, or otherwise certify any such ideas or concepts in application or usage. This material should be verified for applicability and correctness in each user environment. No warranty of any kind available.

Building your own firewall

It’s easy with linux But my recommendation is Don’t bother Unless you want to do it as a

learning experience or you’re REAL broke!

Buy a firewall

There are many vendors who make inexpensive SOHO firewall/routers.

For example, the LinkSys firewall/hub is currently available from amazon.com for $59.99 after a $10 mail in rebate. (and they throw in a free ethernet cable)

There are a LOT of options!

Buy a firewall

http://www.linksys.comhttp://www.netgear.comhttp://www.actiontec.comhttp://www.usr.comhttp://catalog.belkin.comhttp://www.cayman.comhttp://www.microliss.dehttp://www.2wire.com

Buy a firewall

www.cnet.com www.buy.com www.pricewatch.com

Go to any of these sites and search for “firewall”

My firewalls

First try – Redhat 5.2 with ipfwadm

Getting better – RedHat 6.2 with ipchains

Today – RedHat 7.3 with iptables/netfilter

Building your firewall

Hardware

Software

Hardware

Doesn’t have to be current or state of the art hardware

While you can use a 486 system, I would recommend a Pentium, any old Pentium.

You should be able to find a 100 to 400 Mhz Pentium motherboard almost anywhere in the used equipment market

Hardware

You need: Motherboard and processor Case/Power Supply to match Memory Video card/monitor Keyboard/mouse Floppy/CDROM drives Hard drive(s) (total space at least 1.5 Gb) 2 network cards

Hardware

Memory 32 MB minimum 64 MB good 128 MB better

None of the hardware needs to be “State of the Art”

Software

Several Options are available LRP (Linux Router Project) LEAF (Linux Imbedded Appliance

Firewall) CD-Linux DIY Many others, not mentioned here

Use google.com

Linux Router Project

www.linuxrouter.org Boots from a single floppy disk Minimum hardware required Based upon the 2.2 Linux Kernel Seems to be falling into disuse

Linux Imbedded Appliance Firewall (LEAF)

Follow-up to the Linux Router Project Single floppy boot image Also seems to based upon the 2.2

kernel For more information:

http://leaf.sourceforge.net/http://lrp.steinkuehler.net/

CD-Linux

Yet another Linux distribution One where the majority of the files can be

located on a read-only medium, such as CDROM.

More secure since there is no way to change the system without creating a new CD

Hard to keep current for the same reason www.cd-linux.org

Do it Yourself Things you will need

Basic Hardware RedHat Linux version 7.3 If you’re going to build it, you MUST

Protect it Keep it current

Do it Yourself Things you will need

To protect your system you need: TCP wrappers A log scanner A firewall configuration file Network Time Protocol Tripwire

To keep your system current you need: An rpm update manager

TCP Wrappers

Started from inetd Controls access to other daemons

started from inetd Uses configuration files to determine

access /etc/hosts.deny /etc/hosts.allow

Secure Shell

An implementation of the Secure Socket Layer (SSL)

Free for Educational and non-commercial use

Commercial version available Developed at The Helsinki University of

Technology Available on the Internet Included with RedHat Linux 7.0+

Secure Shell

Automatic authentication of users Multiple strong authentication methods Authentication of both ends of

connection Automatic authentication using agents Encryption and compression of data Tunneling and encryption of arbitrary

connections

Secure Shell

Cryptographic algorithms available Triple DES (Default) Blowfish Twofish Arcfour Idea Cast RSA

LogCheck

Linux logs a tremendous amount of info People just don’t read logs Most of what is in the logs is normal The normal stuff hides the important

stuff Let the computer read the logs and

separate the important stuff from the junk

LogCheck

Written by Craig Rowland Scans logs for interesting entries Free Now called LogSentry Available for download at

http://www.psionic.com/abacus/logcheck/ Runs hourly

LogCheck

LogCheck uses four configuration files logcheck.hacking logcheck.violations logcheck.violations.ignore logcheck.ignore

Files are applied in the order shown Every line is a “regular expression”

LogWatch

Another Log Analyzer Distributed standard with RedHat 7.2+ Written by Kirk Bauer <[email protected]> http://www.kaybee.org/~kirk Configuration files in /etc/log.d Runs once a day Does not appear to be as easily

configured as logcheck

http://www.kaybee.org/~kirk

Logrotate

Comes with RedHat Linux Debian does something Different Slackware doesn’t do this at all YMMV Freely available from Redhat.com

Should build on any version of Linux

Logrotate

Check and update /etc/logrotate.conf Allows for keeping old logs Keeps logs from filling up disk Different logs can have different

parameters Can also use files in the directory

/etc/logrotate.d

RPM Update Managers

Updateme Up2date Apt-rpm Autorpm

updateme

Locally written UGA utility Checks for new versions of software Can be configured to use any RedHat

distribution site Configuration file Command line argument

Support status uncertain

/usr/local/etc/updateme.cf

site=acs-mirror.ucsd.eduupdatedir=/linux/redhat/updates/7.3/en/os/i386

site=sunsite.unc.eduupdatedir=/pub/linux/distributions/redhat/updates/7.3/en/os/

i386

up2date

From RedHat Requires registration with RHN (RedHat

Network) Free for the first computer Subscription required for multiple

computers Requires X-11 on the computers to be

managed

APT-RPM

A port of the Debian APT (Advanced Package Tool) program used to manage updates.

Requires that the site providing the updates have a special “apt” index which must be created each time it’s content changes.

Not enough sites do this yet http://freshrpms.net/apt/ or Google

AutoRPM

By Kirk Bauer Can download updates for later

installation Can download and install updates Can do automatic updates or queue

for later Requires a bit of configuration work I like this one

Firewall configuration files

http://www.linux-firewall-tools.com/linux/

http://www.linuxguruz.org/iptables/

The script I have been using is available on this second web site as “IPTABLES Masquerading Firewall” or rc.firewall_023.txt

Firewall configuration files

I like this file for several reasons: It uses the “state” condition of

connections to determine if they are allowed or denied

It is more thorough in it’s handling of icmp traffic

It has provisions for port forwarding for services operated on machines located on the local network.

Download it

Tripwire

Monitors system for modified files Many versions, most commercial Tripwire for linux is open source

under GPL http://sourceforge.net/projects/tripwire

Distributed with RedHat 7.2+ tripwire-2.3.1-10.i386.rpm

Tripwire

Uses passwords and cryptographic signatures to protect configuration files

Default configuration may take some fixing Comes with many non-existent files defined Run it once and use the output to edit the

twpol.txt file. You probably also want to remove /root and /var/log from checking.

Run from cron once a day to audit system

Tripwire

When something changes Tripwire will find it. If it’s OK, then run:

tripwire --update –r /full/path/to/latest/report.twr

If it’s NOT OK, then you may have been compromised

Tripwire and AutoRPM may not play well together, giving some false positives

NTP (Network Time Protocol)

Developed by Dave Mills at The University of Deleware ([email protected])

Sets computer clock automagically Previous version is xntp-3.5.93 and is

on the RedHat 6.1 CDROM Current version is ntp-4.1.1 and is on

the RedHat 7.3 CDROM

NTP

Can set the clock from various sources Reference Time Standards Broadcast Standards (WWVB) GPS receivers Network

Configuration File /etc/ntp.conf

NTP

Network Time Standards Public vs Private Primary vs Secondary Server List

http://www.eecis.udel.edu/~mills/ntp/servers.htm

Pick a server near you Use a “Public” server Do NOT use a “Primary” Server



Backups

I’m usually a big fan of frequent backups, but in the case of the firewall, it really isn’t necessary.

Back up a few of the more critical files which would be a pain to re-create. The rest can be easily rebuilt. The main file I keep copies of is my firewall config file.

Sign up for a bug fix list

Go here and sign up for the redhat.com watch list. They will send you e-mail every time there is a bug fixed in RedHat linux. You NEED to know this…

https://listman.redhat.com/mailman/listinfo/redhat-watch-list/

References

LINUX HOWTO documents Should be on your Install CD, or from http://

metalab.unc.edu/LDP/

http://metalab.unc.edu/LDP/



References

SSH http://www.ssh.com/ (commercial version) http://www.ssh.org/ (educational version)

LogCheck http://www.psionic.com/abacus/logcheck/

NTP RFC 1796 http://www.eecis.udel.edu/~ntp/

http://www.ssh.com/

http://www.ssh.org/

http://www.psionic.com/abacus/logcheck/

http://www.eecis.udel.edu/~ntp/



References

General Security References //www.alw.nih.gov/Security/security.html //www.usg.edu/oiit/support/security/ //csrc.ncsl.nist.gov/ //www.cert.org/

http://www.alw.nih.gov/Security/security.html

http://www.alw.nih.gov/Security/security.html

http://www.usg.edu/oiit/support/security/



http://csrc.ncsl.nist.gov/



http://www.cert.org/



Firewall references

http://www.linux-firewall-tools.com/linux/http://www.fwtk.org/http://www.fwtk.org/mason/http://rcf.mvlan.net/http://tickle.unco.edu/cs442/weitzel/

research.htmlhttp://tickle.unco.edu/cs442/weitzel/execute.htmlhttp://www.linuxsecurity.com/feature_stories/

kernel-netfilter.html

Firewall Cookbook

A step by step how-to

Basic steps to perform

Assemble hardware Install operating system Clean up install and turn off

unnecessary services Install patches and set up autorpm More security stuff Install firewall configuration Final configuration

Actual installation

Assemble the hardware if necessary. Make boot disks if necessary Boot from CDROM or from floppy if

your bios doesn’t support booting from CD

Do a minimum install of RedHat 7.3 (see next few slides)

Installing RedHat 7.3

To simplify things, when I boot the CD I do a “text” install. You may prefer the “gui” installer.

Select Installation Language - “English”

Keyboard Selection - “us” Mouse – “select yours” Installation type – “custom”


Partition your disk. I like Disk Druid, but you can use fdisk. Use separate partitions for / /var /tmp /boot /home


Disk partitioning - Define them in this order /boot – about 64Mb Swap 128Mb or real memory size,

whichever is greater /var – about 128Mb /tmp – about 128Mb /home – the rest of the disk


Disk Partitioning – continued /boot and swap should be primary

partitions. The rest can be in an extended partition

Define all partitions as type ext3 and format them (except for the swap partition, of course)


Boot loader – you need one – I use grub. Install it in the Master Boot Record of

your primary drive You probably don’t need any boot

options You won’t have any other OSes to boot Or need a boot loader password


Ethernet adapters If you have a dhcp server on your

network eth0

[*] use bootp/dhcp [*] activate upon boot

eth1 [*] use bootp/dhcp [ ] activate upon boot


If you don’t have a dhcp server on your network eth0

[ ] use bootp/dhcp [*] activate upon boot

Fill in static information for address, netmask, etc.

eth1 [*] use bootp/dhcp [ ] activate upon boot

Network Configuration

In either case, do NOT enter gateway or nameserver information. Your system will pick this up via DHCP from your ISP.


Enter your hostname Configure the built in firewall

High security Customize to only allow ssh This is only temporary

Language support – American English (or whatever you want)

Select your time zone


Enter a good password for root Add at least one additional user so you

don’t have to always use root [*] Use shadow passwords [*] Enable MD5 passwords [ ] Enable NIS [ ] Enable LDAP [ ] Enable Kerberos


Package Group Selection [*] Printing Support [*] Network Support [*] Router/Firewall [*] Network Managed Workstation [*] Utilities


Start installation, providing additional CDROMs when prompted for.

Build a boot diskette when prompted. When done, remove all media and boot

your new linux system. Connect only one of your ethernet adapters to your local network and boot your new system

Initial setup

Boot your new system with your local network attached to one of the two ethernet cards. Watch the system startup messages for “eth0” to start correctly. Log on and try to ping another host on your local network. If it succeeds, mark that adapter as “eth0” If it fails, swap the cable to the other adapter, reboot, and try again.

Initial setup

Edit /etc/aliases and uncomment the last line of the file and fix the address to a valid address to receive mail sent to root Old

#root marc

New root [email protected]

Run the “newaliases” command

Initial setup

Edit the file /etc/hosts and fix it Before

127.0.0.1 pitbull localhost.localdomain localhost

After127.0.0.1 localhost.localdomain localhost192.168.1.121 pitbull pitbull.halshome.net

Or whatever your local address and hostname are

Initial setup

Turn off unused serviceschkconfig –list | grep on | more

Will show all of the services currently on, one per line.

This list looks like this:

Initial setup

keytable atd syslog gpm sendmail kudzu netfs

network random rawdevices apmd ipchains iptables crond

anacron lpd portmap xfs xinetd rhnsd autofs

nfslock isdn sshd ip6tables

Initial setup

For each of the services not desired:

chkconfig --level 123456 service off

Configure TCP Wrappers

/etc/hosts.deny## hosts.deny# This file describes the names of the hosts

which # are *not* allowed to use the local INET

services,# as decided by the '/usr/sbin/tcpd' server.#ALL: ALL

Configure TCP Wrappers

/etc/hosts.allow## hosts.allow#sshd: 192.168.1.

Configure network

Plug your internet connection into the unused ethernet adapter (eth1)

Edit the file:/etc/sysconfig/network-scripts/ifcfg-eth1

And change the lineONBOOT=no

ToONBOOT=yes

And Re-boot

Configure network

Use the commands ifconfig -a netstat –rn

To check the status of the network. It should look like this:

ifconfig eth0

eth0 Link encap:Ethernet HWaddr 48:54:E8:28:03:21

inet addr:192.168.1.122 Bcast:192.168.1.255 Mask:255.255.255.0

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

RX packets:172 errors:0 dropped:0 overruns:0 frame:0

TX packets:97 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:100

RX bytes:19664 (19.2 Kb) TX bytes:10409 (10.1 Kb)

Interrupt:11 Base address:0xd000

ifconfig eth1

eth1 Link encap:Ethernet HWaddr 48:54:E8:28:05:2F

inet addr:65.190.68.197 Bcast:65.190.68.199 Mask:255.255.255.252

UP BROADCAST NOTRAILERS RUNNING MULTICAST MTU:1500 Metric:1




RX bytes:2849 (2.7 Kb) TX bytes:2335 (2.2 Kb)

Interrupt:11 Base address:0xcc00

ifconfig lo

lo Link encap:Local Loopback

inet addr:127.0.0.1 Mask:255.0.0.0

UP LOOPBACK RUNNING MTU:16436 Metric:1




RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

netstat -rn

Kernel IP routing table

Destination Gateway Genmask Flags MSS Window irtt Iface

65.190.68.196 0.0.0.0 255.255.255.252 U 40 0 0 eth1

192.168.1.0 0.0.0.0 255.255.255.0 U 40 0 0 eth0

127.0.0.0 0.0.0.0 255.0.0.0 U 40 0 0 lo

0.0.0.0 65.190.68.198 0.0.0.0 UG 40 0 0 eth1

You’re online!

Your machine is now connected to the internet, but is not yet acting as a firewall for the network behind it.

First, let’s check that sendmail works

Initial setup

Test sendmailsendmail –v rootdatadata. Look for a line containing:

250 xxxxxxxx Message accepted for delivery

Check for delivery

Additional sendmail setup

Since we will NOT be running sendmail as a daemon, we need to make sure that mail which gets queued as undelivered will get retried.

We will create a file in the hourly cron directory to invoke sendmail to run the mail queues

Additional sendmail setup

cd /etc/cron.hourly

echo '#!/bin/bash' > sendmail

echo /usr/sbin/sendmail –q >> sendmail

chmod +x sendmail

Installing software

We have a few packages which were not installed with the distribution.

Let’s get them and install them. We’re now connected to the internet

so we can do this

Get AutoRPM

ftp ftp.kaybee.org Logon as anonymous cd /pub/redhat/RPMS/noarch bin prompt mget autorpm* quit

Install AutoRPM

rpm -ivh autorpm-2.9.3-1.noarch.rpm autorpm –v It should report version 2.9.3. By default, AutoRPM only tells you

about updates and doesn’t do anything about them.

We want to modify this behavior

Configure AutoRPM

Edit the file /etc/autorpm.d/autorpm.conf

Change line 12 to reflect the architecture of your machine (probably have to remove “i686”

Uncomment line 49 to allow automatic updating of the AutoRPM package to the latest “stable” release

Configure AutoRPM

Edit the file /etc/autorpm.d/redhat-updates.conf

Change line 28 from Install(Interactive); to Install(Auto);

Change line 33 from Auto_Follow_Deps(No); to Auto_Follow_Deps(Yes);

Run AutoRPM

Now run AutoRPM in order to update the software on your new system

autorpm --notty “auto” &

E-mail will be sent to root with the results.

Install Lynx

We need a web browser to download files, but don’t want the overhead of X-Windows

Install lynx

It’s on the RedHat CDROM, volume 3

mount -o ro /dev/cdrom /mnt/cdromcd /mnt/cdrom/RedHat/RPMSrpm -ivh lynx-2.8.4-18.i386.rpmcd /rootumount /dev/cdrom

Use lynx to download the iptables configuration file

lynx http://www.linuxguruz.org/iptables/ Use the down arrow key to scroll the page

down until you see the entry for “IPTABLES masquerading firewall”

Move the cursor to this line. The URL will be highlighted

Press the “d” key to download this file Use the default filename,

“rc.firewall_023.txt

Edit the rc.firewall file

Edit the file you just downloaded Add the following two lines near the

top of the file in the initial comments

# chkconfig: 2345 11 92# description: iptables packet filtering

firewall


Find the line “…location of the iptables…” Change IPTABLES="/usr/sbin/iptables" To IPTABLES="/sbin/iptables"

Find the line “---Begin Firewall---” Change DEFAULT_EXTIF="ppp0" To DEFAULT_EXTIF="eth1"


So we can run ntp, we have to open a hole in the firewall for the ntp port.

Find the string “DNS” in the file. It occurs twice

Both times, replicate the three lines starting with the “DNS” line

Both times, on the first replicated line, change “DNS” to “NTP”

On the second and third lines change “53” to “123” and remove the comment “#” character from column 1.

Now configure iptables

cd /etc/rc.d/init.d mv iptables iptables.orig mv ipchains ipchains.orig cp /root/rc.firewall_023.txt iptables chmod +x iptables chkconfig --del iptables chkconfig --add iptables

Start your new firewall

Reboot the system. Watch the system console for

rejections from the firewall. They will probably start almost immediately, and look something like this:

Firewall message

Aug 7 14:01:17 pitbull kernel: fp=SPECIALPORT:1 a=DROP IN=eth1 OUT= MAC=00:a0:d2:16:0f:e0:00:10:e8:0d:15:2c:08:00 SRC=67.251.1.229 DST=65.190.68.197 LEN=48 TOS=0x00 PREC=0x00 TTL=115 ID=17663 DF PROTO=TCP SPT=4037 DPT=27374 WINDOW=2144 RES=0x00 SYN URGP=0

Firewall messages

The messages are logged to /var/log/messages

This particular message shows a probe to port 27374 (the backdoor installed by the SubSeven worm) from a computer with IP address 67.251.1.229. This address resolves to a Canadian uunet subscriber 1Cust229.tnt2.oxnard.ca.da.uu.net

Install ntp

We need to install the network time protocol program to synchronize the clock on our server to a master clock

It’s on the RedHat CDROM, volume 1mount -o ro /dev/cdrom /mnt/cdromcd /mnt/cdrom/RedHat/RPMSrpm -ivh ntp-4.1.1-1.i386.rpm \ libcap-1.10-8.i386.rpm

Configure ntp

Go to: http://www.eecis.udel.edu/~mills/ntp/clock2.htm

Select one or two servers close to you

Edit /etc/ntp.conf Make it look like this:

/etc/ntp.conf

Server server1.somewhere.edu

Server server2.somewhere.else.com

driftfile /etc/ntp/drift

Logfile /var/log/ntp.log

More ntp configuration

Edit the file /etc/ntp/step-tickers And put in the two servers you

selected, one per line with no other information

server1.somewhere.edu server2.somewhere.else.com

ntp

Start ntp with the command/etc/rc.d/init.d/ntpd start

You should see two messages:

ntpd: Synchronizing with time server: [ OK ]

Starting ntpd: [ OK ]

ntp

Check to see if ntp is running with the commandsntpdcpeersquit

Checking ntp

[root@pitbull root]# ntpdcntpdc> peers remote local st poll reach delay offset disp========================================================================dns2.uga.edu 192.168.1.122 2 64 1 0.05865 43190.870 7.93750=dns1.uga.edu 192.168.1.122 2 64 1 0.05772 43190.870 7.93750ntpdc> quit[root@pitbull root]#

A minor fix

Edit the file /etc/sysconfig/i18nChange the line

LANG="en_US.iso885915"

ToLANG="C"

This fixes a problem with the ls command sort order.

Other things you may fix

Edit /root/.bashrc Remove the annoying aliases for rm, cp,

and mv Add any aliases you may want. I like

alias l='ls –Fl‘

Reload with the command . .bashrc

Other things you may fix

Since you have working log scanner (logwatch) and a working log manager (logrotate) nothing needs to be done here.

I personally would replace logwatch with LogSentry from Psionic Technologies and tweak the logrotate configuration files to keep the firewall logs a bit longer, but then that’s just me…

Installing Tripwire

It’s already installed, running, and sending e-mail to root once a day demanding to be configured

Configuring Tripwire

/etc/tripwire/twinstall.sh Answer prompts Use good passphrases

tripwire --init tripwire –check

You WILL get lots of errors

Configuring Tripwire policy

Check output and edit twpol.txt, removing all 156 files reported as missing. This could be very tedious, so lets use a script…

cd /etc/tripwireCreate the file tw.a containing:/No such file/ {print "/" prev "/ s/^ /#/"}

/Filename:/ {prev = $2

gsub("/", "\\/", prev)}

Updating Tripwire Policy

tripwire --check > tw.reportawk -f tw.a tw.report > tw.sedsed -f tw.sed twpol.txt > twpol.newvi twpol.new

update the HOSTNAME variablecomment out the entries for

/root/var/log

Tripwire

mv twpol.txt twpol.txt.origmv twpol.new twpol.txttripwire --update-policy -Z low

twpol.txttripwire –checkrm tw.a tw.sed tw.report twpol.txt.orig

Tripwire

You will be mailed a report from tripwire every day. Check the report. It may show changes to files on your system. These changes may be due to the AutoRPM program automatically installing updates. If this is the case then you need to run tripwire in update mode. Here’s a script to make this easier

twupdate script

Put this script in /usr/local/bin Make it executable Run it when you need to update the

tripwire database

twupdate script

#!/bin/bash

if [ $USER = root ] ; then

dir='/var/lib/tripwire/report'

fn=$(ls -r $dir | head -1)

tripwire --update -a -r $dir/$fn

else

echo This command must run as root

fi

Finally, updating your kernel

Nothing here will automatically update the kernel of your linux system.

I believe that this is a good thing. I also believe you periodically do

need to put a new kernel in production to fix problems.

The RedHat report will tell you when.

Updating the kernel

Go to RedHat.com (or some other distribution site

Download the new kernel Install it with “rpm -ivh” so that it is

installed separately, and doesn’t replace your current kernel (which is what would happen if you install with “rpm -Uvh”

Getting the new kernel

ftp ftp.redhat.comLog on as anonymous

cd /pub/redhat/linux/updates/7.3/en/os/i586(or whatever your architecture is)

Download the “non-smp” kernelbinpromptmget kernel-2.4*quit

Installing the new kernel

rpm -ivh kernel-2.4.18-5.i586.rpm Reboot Make sure the new kernel is selected

on the “grub” menu. If it isn’t, then use the cursor keys to select it and press “enter”

Make sure everything works.

Installing the new kernel

Finally, if the grub boot loader comes up with your new kernel on the top line and the second entry is the default (highlighted): Edit /etc/grub.conf Change “default=1” To “default=0”

Session 6306Th-th-th-that’s all folks

Questions?

building a redhat linux firewall – a user experience

Documents

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ideal linux firewall

excellent firewall

ipchainstoday redhat

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