1. prepend the following two opendns nameservers in your /etc/resolv.conf file
208.67.222.222
208.67.220.220
2. create a free account with opendns
3. add your sunray server IP to your opendns account and verify access to opendns website from your server IP
4. turn on porn site block from your opendns account.
5. wait 5 mins and walla!
Now users on your sunray server will be blocked from accessing porn sites
