Bhutan ICT

Sometime having a white listed IP group in squid is problematic due to DHCP. It works perfectly on static IP address when assigned to an individual. But if you use MAC address you need not worry about IP address. Squid configuration for IP based filter. acl AllowIP src 192.168.50 acl AllowIP src 192.168.2 http_access allow AllowIP Squid configuration for MAC based filter. Create a file in squid location. Here I have create mac.txt file under squid location i.e (/etc/squid/). acl MAC arp "/etc/squid/mac.txt" http_access allow MAC My mac.txt file would contain something like this. 00:32:1e:7d:2a:00 00:xx:xx:xx:xx:xx * MAC address under windows will be shown as xx-xx-xx-xx-xx-xx where as in Linux xx:xx:xx:xx:xx:xx Make sure that your http_access allow line is before http_access deny all, else your rule will not work.

Under linux OS, we use iptables to secure the machine from any other external attack. In current scenario I am forwarding the packages from local interface to external interface and i have squid configured which will be acting as transparent proxy. Only selective port numbers are open for the network. 1. Save the script to a file. 2. Give permission to execute. chmod +x filename . 3. Execute the file as follows ./filename 4. save the output of the script to system iptables file, by running the command service iptables save 5. You are done, start/restart the iptables service. service iptables restart Script: #!/bin/sh # chmod +x file name to execute # eth0 LAN # eth1 WAN # Local IP range 192.168.0.0/25 # NATing # Transparent proxy iptables -F iptables -X iptables -t nat -F iptables -t nat -X iptables -t mangle -F iptables -t mangle -X iptables -P INPUT ACCEPT iptables -P FORWARD ACCEPT iptables -P OUTPUT ACCEPT iptables -A INPUT -i lo -j ACCEPT iptables -A...

In some network where you have to enter the IP Address of the proxy server to access the internet and you are not able to use the yum command to update your system. You normally put the Proxy Server IP and Ports in your browser setting, but in Linux box that doesnot solve the problem. You need to edit the file /etc/yum.conf , and make a new entry in the bottom of the file as below: proxy=http://<Proxy Address>:<proxy port> Now run the yum command and you will see its now working.