How to Block a Website Using Squid Proxy Server 4.7 version on CentOS 7.6

To Blocking the websites using Squid Proxy Server

Procedure

Lets check the version of squid proxy server.

[root@linuxhelp ~]# squid -v
Squid Cache: Version 4.7-20190507-r2e17b0261
Service Name: squid
configure options:  '--prefix=/usr' '--includedir=/usr/include' '--datadir=/usr/share' '--bindir=/usr/sbin' '--libexecdir=/usr/lib/squid' '--localstatedir=/var' '--sysconfdir=/etc/squid'

Go to the location of Squid configuration file.

[root@linuxhelp ~]# cd /etc/squid

List the contents in the squid.

[root@linuxhelp squid]# ll
total 360
-rw-r--r-- 1 root root    692 May 31 09:12 cachemgr.conf
-rw-r--r-- 1 root root    692 May 31 09:12 cachemgr.conf.default
-rw-r--r-- 1 root root   1800 May 31 09:10 errorpage.css
-rw-r--r-- 1 root root   1800 May 31 09:12 errorpage.css.default
-rw-r--r-- 1 root root  12077 May 31 09:12 mime.conf
-rw-r--r-- 1 root root  12077 May 31 09:12 mime.conf.default
-rw-r--r-- 1 root root   2553 May 31 09:12 squid.conf
-rw-r--r-- 1 root root   2553 May 31 09:12 squid.conf.default
-rw-r--r-- 1 root root 318265 May 31 09:12 squid.conf.documented

Configure the squid.conf file as follows.

[root@linuxhelp squid]# vim squid.conf
acl test src 192.168.7.102
acl block dstdomain 

Create a file named block.txt to block the websites that are set in this file.

[root@linuxhelp squid]# vim block.txt
.facebook.com
.twitter.com

To know the exact location of the block.txt, execute the following command.

[root@linuxhelp squid]# pwd
/etc/squid

Open the squid configuration file and set the path in the dstdomain rule.

[root@linuxhelp squid]# vim squid.conf
acl test src 192.168.7.102
acl block dstdomain “/etc/squid/block.txt”
http_access deny test block
http_access allow test

Reload the squid proxy server.

[root@linuxhelp squid]# squid -s
WARNING: Cannot write log file: /var/logs/cache.log
/var/logs/cache.log: Permission denied
         messages will be sent to 'stderr'.

Set the sticky bit and full permissions to get rid of the above warning.

[root@linuxhelp squid]# chmod -R 1777 /var/logs

Reload the squid proxy sevrer.

[root@linuxhelp squid]# squid -s

Check the ip address of the squid proxy server by running the following command.

[root@linuxhelp squid]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/ether 00:0c:29:f9:d6:3d brd ff:ff:ff:ff:ff:ff
    inet 192.168.7.229/24 brd 192.168.7.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::348f:40bb:9186:7a4/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:1c:2f:d7 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:1c:2f:d7 brd ff:ff:ff:ff:ff:ff

Open the browser, click on open Menu: and select options. Enter proxy in the search bar of Mozilla Firefox and select proxy settings. Set the squid proxy server in the following way. Open the www.facebook.com and www.twitter.com to verify the websites that had blocked by the squid proxy server that was set in the block.txt With this, blocking of websites using squid proxy server comes to end.