Squid Proxy Hide System’s Real IP Address

Posted on in Categories , , , , , last updated January 17, 2016

My squid proxy server is displaying system’s real IP address. I’ve a corporate password protected squid proxy server located at 202.54.1.2. My clients work from home or offices via A/DSL / cable connections. Squid should hide all system’s IP address, but it is forwarding and displaying the system’s IP address. How do I configure squid to hide client’s real IP address?

Squid Proxy WARNING! Your cache is running out of filedescriptors error and solution

Posted on in Categories , , , , , , , , , , , last updated June 18, 2009

I’ve Squid Proxy server with over 100 Windows workstation. I see following error message in my cache.log file – “WARNING! Your cache is running out of filedescriptors”. Do I need to filter proxy server requests to avoid this problem? How do I fix this problem under CentOS / Fedora / RHEL / Debian Linux?

Squid Block any Domain Name Accessing the Internet

Posted on in Categories , , , , last updated February 6, 2008

Q. How do I block any website accessing the Internet using squid proxy server?

A. You can simply use squid ACL to block access to any web site. There are 3 steps:

#1. Create a text file with blocked domain name list such as baddomain1.com, mail.yahoo.com, gmail.com and so on

#2. Define Acl

#3. Restart squid

First, create a file called /etc/squid/blocked.domains.acl
# vi /etc/squid/blocked.domains.acl
Append domain names,
gmail.com
baddomain.com
sex.com
mail.yahoo.com

Save and close the file. Open squid.conf file:
# vi /etc/squid/squid.conf
Create acl called blockeddomain:
acl blockeddomain dstdomain "/etc/squid/blocked.domains.acl"
Deny http access, enter:
http_access deny blockeddomain
Close and save the file. Restart squid proxy server:
# /etc/init.d/squid restart

Squid Proxy Server Mac Address based filtering

Posted on in Categories , , , , last updated November 1, 2007

Q. I’m using squid proxy server under CentOS Linux version 5. How to filter a particular MAC address under squid?

A. Not all operating system supports Mac address based filtering. For some operating systems. Squid calls these “ARP ACLs” and they are supported on Linux, Solaris, and BSD variants.

How do I set up ACL’s based on MAC address?

Open squid.conf:
# vi /etc/squid/squid.conf
Local acl, section and append ACL as follows:
acl macf1 arp mac-address
acl macf2 arp 00:11:22:33:44:55
http_access allow macf1
http_access allow macf2
http_access deny all

Save and close the file. Restart squid server:
# /etc/init.d/squid restart