How to Transparent Proxy With Squid

Partition Table Information
Filesystem Size Used Avail Use% Mounted on
/dev/hda2 12G 663M 12G 6% /
tmpfs 1005M 0 1005M 0% /dev/shm
/dev/hda1 102M 36M 66M 36% /boot
/dev/hda7 3.2G 33M 3.2G 1% /home
/dev/hda6 5.0G 131M 4.9G 3% /tmp
/dev/hda3 16G 363M 15G 3% /var
/dev/hdb1 38G 17G 21G 45% /var/cache/squid

Package for Installation: squid-2.5.STABLE9-4.2
Checking for Installation: rpm –qa grep squid
Installing Squid through yast2:
yast2->Install and Remove S/W->Ctrl+S->search for squid->then install

Configuration File: /etc/squid/squid.conf

http_port 8080
cache_dir ufs /var/cache/squid 38000 16 256
cache_access_log /var/log/squid/access.log
cache_log /var/log/squid/cache.log
cache_store_log /var/log/squid/store.log

http_access allow all

httpd_accel_host virtual
httpd_accel_port 80
httpd_accel_with_proxy on
httpd_accel_uses_host_header on

Traffic Redirection Rule (iptables rule for transparent proxy):
iptables –A PREROUTING –i eth0 –p tcp –m tcp –dport 80 –j REDIRECT –to-port 8080

Note: Save the rule in a file by using the following command, because when the system reboots it flushes all iptables rules

iptables-save > redirect

Now restore the iptables rules by specifying the following command in the /etc/init.d/boot.local file:

Iptables-restore <>

How to Install Freeradious

Before installing freeradius go to “spec for freeradius.doc” for installing prerequisite libraries/packages.

Take the following steps to build and install the server:

tar –zxvf freeradius.1.02.tar.gz
cd freeradius.1.02
./configure --localstatedir=/var --sysconfdir=/etc
make
make install

That means binaries will get installed in /usr/local/{bin,sbin},
manpages in /usr/local/man, configuration files in /etc/raddb, and
logfiles in /var/log and /var/log/radacct.

Note: you will not able to make it unless you install all rpm which are pre-requisite and you can find it in the file /path of freeradius.1.20/suse/freeradius.spec

To start the server in debugging mode, do:

radiusd –X

For the configuration to Ras, we go to the directory of /etc/raddb, we find three main configuration files 1) radiusd.conf 2)client.conf 3)sql.conf ( if we want our users to use mysql)
For further configuration go to these files and see the lines which are highlighted in red color.
Before it run the service of mysql as follows
/etc/init.d/mysql start
mysql –uroot
mysql> make database radius;
mysql>use radius;
mysql> source radius <>exit;

Now configure your radiusd.conf file first, and give the spool there and enable the sql entries if u want to use it.
Then configure your client.conf and give at the client section the name of your Ras server.
Then configure your sql.conf file and enable the entries for connecting to database.

Start the debugging mode of radius again as follows

radiusd –X


For the configuration of dialup admin, just go the directory of dialup admin which is in the directory of freeradius.1.20
And just see the entries in the admin.conf file, you will see every thing in red color there…

For any further help contact imrance@hotmail.com

Email Servers

The first step to minimizing the effect of viruses is to use an email server that filters
incoming emails using antivirus software. If the server is kept up to date, it will catch the
majority of Mass Mailer (MM) worms. Ask your Internet Service Provider (ISP) if they
offer antivirus protection and spam filtering on their email servers. This service is
invaluable and should always be included as the first line of defense.
Many companies house an internal email server that downloads all of the email from
several external email accounts and then runs an internal virus filter. Combining an
internal email server with the ISP protection is a perfect for a company with an IT staff.
This option adds an extra layer of control, but also adds more administration time.
Sample specs for an internal email server are:
Setup #1
Linux: OS
Sendmail: Email server
Fetchmail: Grabs email from external email addresses
F-prot: Antivirus
SpamAssassin: Spam Filter
Setup #2
Win 2003 Server: OS
Exchange: Email server
Symantec antivirus: Antivirus
Exchange Intelligent Message Filter: Spam Filter
Software Updates
Keep you software up to date. Some worms and viruses replicate through vulnerabilities
in services and software on the target system. Code red is a classic example. In august
2001, the worm used a known buffer overflow vulnerability in Microsoft’s IIS 4.0 and
5.0 contained in the Idq.dll file. This would allow an attacker to run any program they
wanted to on the affected system. Another famous worm called Slammer targeted
Microsoft SQL Server 2000 and Microsoft Desktop Engine (MSDE) 2000.
When updating your software, make sure to disable features and services that are not
needed. Some versions of WinNT had a web server called IIS installed by default. If you
do not need the service, make sure it is turned off (Code red is a perfect example). By
only enabling services you need, you decrease the risk of attack.