Suppose I want to block Facebook permanently. To do this, I have followed following processes:
#host -t a www.facebook.com
Sample output:
www.facebook.com has address 69.171.224.40
Find CIDR
#whois 69.171.224.40 | grep CIDR
Sample output:
CIDR: 69.171.224.0/19
To prevent outgoing access to www.facebook.com
Approach 1:
#iptables -I FORWARD -p tcp -d 69.171.224.0/19 -j DROP
Approach 2:
#iptables -I FORWARD -p tcp -d www.facebook.com -j DROP
Both Approaches work well. In approach 1, IP address may be changed so it will not block Facebook permanently. I don't know about approach 2 whether it will block Facebook permanently or not. If above approaches are not right way to block a domain permanently, how can I do it?
Best Answer
Using squid following thing if you use it do the same.