How to Setup Squid Proxy in Ubuntu Server 14.04

Squid is a proxy server that provide cache services to the clients. It redirects client requests from web browsers to the proxy server and delivers the client’s requests and keeps a copy of them in the proxy hard disk cache. This will speeding up internet access especially for frequently-used files and reduces internet bandwidth. Squid program does not requires intensive CPU usage. To increase efficiency, i would recommend to buy faster disks or add more memory into the squid proxy server. This post describes basic steps on how to Setup Squid Proxy in Ubuntu Server 14.04.

 

 

How to Setup Squid Proxy in Ubuntu

1. Install Squid 3 :

ehowstuff@ubuntu14:~$ sudo apt-get install squid3 -y

2. Configure common setting :

ehowstuff@ubuntu14:~$ sudo vi /etc/squid3/squid.conf

Around line 919, define allowed LAN segment :

..
acl lan_ehowstuff src 192.168.0.0/24
..

Around line 1058, allow defined LAN :

..
http_access allow lan_ehowstuff
..

Listen on port 3128 :

# Squid normally listens to port 3128
http_port 3128

Save the configuration

3. Configure Squid Proxy Authentication using digest authentication scheme :

a. Install the program ‘htdigest’ :

ehowstuff@ubuntu14:~$ sudo apt-get install apache2-utils -y

b. Setting up user :

sudo htdigest -c /etc/squid3/passwords realm_name user_name

Example :

ehowstuff@ubuntu14:~$ sudo htdigest -c /etc/squid3/passwords proxy proxyuser1
Adding password for proxyuser1 in realm proxy.
New password:
Re-type new password:

c. At line 335-337, add digest squid authentication configuration. Please note that the file digest_pw_auth has been renamed to digest_file_auth in ubuntu 14.04. By default, the digest authentication scheme is not used unless the program is specified.

auth_param digest program /usr/lib/squid3/digest_file_auth -c /etc/squid3/passwords
auth_param digest realm proxy
acl authenticated_ehowstuff proxy_auth REQUIRED
http_access allow authenticated_ehowstuff

4. Restart the Squid to take affect the new configuration :

ehowstuff@ubuntu14:~$ sudo initctl restart squid3
squid3 start/running, process 2185

or

ehowstuff@ubuntu14:~$ sudo service squid3 restart

5. Verify port 3128 are listening :

ehowstuff@ubuntu14:~$ sudo netstat -plunt | grep 3128
tcp6       0      0 :::3128                 :::*                    LISTEN      2185/squid3

6. Configure at client browser :

7. Everytime you open the browser, proxy authentication box will be prompted :

8. Monitor the access log from proxy server. You can see proxyuser1 as authenticated user :

ehowstuff@ubuntu14:~$ sudo tail -f /var/log/squid3/access.log
RECT/173.194.126.55 text/html
1409354804.372   1073 192.168.0.1 TCP_MISS/200 776 GET http://xml.alexa.com/data? proxyuser1 HIER_DIRECT/23.21.109.107 text/xml
1409354842.754    963 192.168.0.1 TCP_MISS/200 2285 POST http://sd.symcd.com/ proxyuser1 HIER_DIRECT/23.51.43.27 application/ocsp-response
1409354843.234   1489 192.168.0.1 TCP_MISS/200 915 POST http://ocsp.digicert.com/ proxyuser1 HIER_DIRECT/117.18.237.29 application/ocsp-response
1409354843.454   1549 192.168.0.1 TCP_MISS/200 2285 POST http://sd.symcd.com/ proxyuser1 HIER_DIRECT/23.51.43.27 application/ocsp-response
1409354848.074   3249 192.168.0.1 TCP_MISS_ABORTED/000 0 POST http://ocsp.thawte.com/ proxyuser1 HIER_NONE/- -
1409354848.877   3248 192.168.0.1 TCP_MISS_ABORTED/000 0 POST http://ocsp.thawte.com/ proxyuser1 HIER_DIRECT/199.7.71.72 -
1409354853.997   1120 192.168.0.1 TCP_MISS/200 794 GET http://hsrd.yahoo.com/_ylt=A86.IsJVDAFUTGsAVsJUqcB_;_ylu=X3oDMTQ0aHJqM2NuBGNjb2RlA2hvbWVydW4yBGNwb3MDMARnAzAyMTMtMGExNGQ5Zjc1NWZkZGUyYTY5M2E0ZmViNzE0MDUwOTctMDAxNARpbnRsA215BHBrZ3QDNARwb3MDMgRzZWMDdGQtb2ZsLWIEc2xrA3RpdGxlBHRlc3QDNjg0BHdvZQM5MTc5OTMzMg--/RV=1/RE=1410564437/RH=aHNyZC55YWhvby5jb20-/RO=2/RU=aHR0cHM6Ly9teS5zcG9ydHMueWFob28uY29tL2ZhbnRhc3kvc29jY2VyL3ByZW1pZXItbGVhZ3Vl/RS=%5EADA7H0JFo.Ud2RQRqK4zKbm5QoTGVg- proxyuser1 HIER_DIRECT/206.190.39.139 text/html
1409354854.482    280 192.168.0.1 TCP_MISS/200 446 GET http://toolbarqueries.google.com/tbr? proxyuser1 HIER_DIRECT/58.27.61.123 text/html
1409354854.750    549 192.168.0.1 TCP_MISS/200 4214 GET http://xml.alexa.com/data? proxyuser1 HIER_DIRECT/23.21.109.107 text/xml

I hope that above guidelines on how to Setup Squid Proxy in Ubuntu Server will help system administrator to start installing their own proxy server.