How to Install and Configure Squid Server in CentOS 6.5

How to Install and Configure Squid Server in CentOS 6.5

How to Install and Configure Squid Server in CentOS 6.5 

Squid proxy :

Squid is a proxy server for caching and filtering web content . Squid proxy is used by various organisation and internet providers to reduce bandwidth and to increase response time .Squid proxy service will cache the requested web-content and re-using it for the further request of the same content .

[root@ansh ~]# yum install squid*

By default squid configuration file “/etc/squid/squid.conf” will contains recommended minimum configuration  and squid caching feature will work without making any changes . Recommended minimum configuration will looks like the below

#

# Recommended minimum configuration:

#

acl manager proto cache_object

acl localhost src 127.0.0.1/32 ::1

acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1

# Example rule allowing access from your local networks.

# Adapt to list your (internal) IP networks from where browsing

# should be allowed

acl localnet src 10.0.0.0/8     # RFC1918 possible internal network

acl localnet src 172.16.0.0/12  # RFC1918 possible internal network

acl localnet src 192.168.0.0/24 # RFC1918 possible internal network

acl localnet src fc00::/7       # RFC 4193 local private network range

acl localnet src fe80::/10      # RFC 4291 link-local (directly plugged) machines

acl SSL_ports port 443

acl Safe_ports port 80          # http

acl Safe_ports port 21          # ftp

acl Safe_ports port 443         # https

acl Safe_ports port 70          # gopher

acl Safe_ports port 210         # wais

acl Safe_ports port 1025-65535  # unregistered ports

acl Safe_ports port 280         # http-mgmt

acl Safe_ports port 488         # gss-http

acl Safe_ports port 591         # filemaker

acl Safe_ports port 777         # multiling http

acl CONNECT method CONNECT

#

# Recommended minimum Access Permission configuration:

#

# Only allow cachemgr access from localhost

http_access allow manager localhost

http_access deny manager

# Deny requests to certain unsafe ports

http_access deny !Safe_ports

# Deny CONNECT to other than secure SSL ports

http_access deny CONNECT !SSL_ports

# We strongly recommend the following be uncommented to protect innocent

# web applications running on the proxy server who think the only

# one who can access services on "localhost" is a local user

#http_access deny to_localhost

#

# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS

#

# Example rule allowing access from your local networks.

# Adapt localnet in the ACL section to list your (internal) IP networks

# from where browsing should be allowed

http_access allow localnet

http_access allow localhost

# And finally deny all other access to this proxy

http_access deny all

# Squid normally listens to port 3128

http_port 3128

# We recommend you to use at least the following line.

hierarchy_stoplist cgi-bin ?

# Uncomment and adjust the following to add a disk cache directory.

#cache_dir ufs /var/spool/squid 100 16 256

# Leave coredumps in the first cache dir

coredump_dir /var/spool/squid

# Add any of your own refresh_pattern entries above these.

refresh_pattern ^ftp:           1440    20%     10080

refresh_pattern ^gopher:        1440    0%      1440

refresh_pattern -i (/cgi-bin/|\?) 0     0%      0

refresh_pattern .               0       20%     4320

Step 2» Now start squid service

[root@ansh ~]# service squid start

and type this below command to start squid service automatically while booting.

[root@ansh ~]# chkconfig --levels 235 squid on

Step 3 » Setup your web browser to access Internet through proxy server on port 3128 .

IE : Tools » Internet options »Connections » LAN settings » Choose “Use a proxy server for your LAN” » Type your Proxy server ip (192.168.0.150) and port no 3128

Firefox : Options / Preferences » Advanced » Network » Settings » Choose “Manual proxy configuration ” » Type your Proxy server ip (192.168.0.150 ) and port no 3128

Step 4 » Browse some sites and check the access log file on proxy server

[root@ansh ~]# tail -f /var/log/squid/access.log

Restricting Access to specific web sites :

For example , we can see how to block facebook.com and gmail.com .

Step 1 » create a file ( /etc/squid/blockedsites.squid ) and add the site names one per line.

[root@ansh ~]# cat /etc/squid/blockedsites.squid
#blocked sites
www.facebook.com
www.gmail.com

Step 2 » Open the /etc/squid/squid.conf and create a new acl ” blocksites” and acl type “dstdomain” in the acl section like the below .

acl Safe_ports port 488         # gss-http

acl Safe_ports port 591         # filemaker

acl Safe_ports port 777         # multiling http

acl CONNECT method CONNECT

# ACL blocksites

acl blocksites dstdomain "/etc/squid/blockedsites.squid"

and add the following line “http_access deny blocksites” to http_section to deny the access to the acl “blocksites” .

# Recommended minimum Access Permission configuration:

#

# Only allow cachemgr access from localhost

http_access allow manager localhost

# Deny access to blocksites ACL

http_access deny blocksites

Step 3 » Now restart squid service

[root@ansh ~]# service squid restart




Step 4 » Try to access facebook.com in your browser . you could see the blocked page as below .

OK... Enjoy All of you...