Sunday, April 07, 2013

Install and Configure Squid Transparent Proxy on Cents OS 6

Tech Blog - A quick how to on installing squid and configuring it to work with SquidGuard or Dansguardian for web content filtering, Squid - is a proxy server and web cache, there are many thing Squid is capable off, for this how to were just doing proxy configuration that can work with Dansguardian a web content filtering software or SquidGuard a URL redirector software.

First lets install Squid using yum repository

#yum install squid.i686

Once installed we need to edit /etc/squid/squid.conf

#vi /etc/squid/squid.conf

Below is sample squid configuration file

#
# 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 192.168.1.0/24 # RFC1918  internal networkm replace the IP to your internal IP
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
# 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, you can also specify the ext ip aside from the port
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

# In my case I'm using Dansguardian hence need the entry below, otherwise comment out below entry to your server
visible_hostname something.somethingdomain.com

## Uncomment below lines if you going to use SquidGuard, in order for Squid to pass the traffic to squidguard
#url_rewrite_program /usr/bin/squidGuard -c /etc/squid/squidguard.conf
#url_rewrite_children 5

#Run the daemon as squid user and group
cache_effective_user squid
cache_effective_group squid

Save and exit once done, then start squid, if there are errors in your config files squid will not start or reload

#/etc/init.d/squid start

If squid is already running you can reload the configuration file
#squid -k reload

Once started check if port 3128 is listening on the server and go to your browser set proxy setting to the server IP running squid and port 3128.


Enjoy!


No comments:

For suggestion and concerns E-mail