Could tell me how to setup the cron job, I have got the overide working now, sweet.
Hopefully no more accidents when the kids are searching on google!
Thought you might be interested in something I figured out this weekend… The override for "encrypted.google.com" does not work if someone browses to "https://encrypted.google.com". Not 100% sure of all the reasons why but I was able to figure out two options for solving the problem...
1.) You can block outbound access on port 443 to the IP addresses that encrypted.google.com resolves to. Unfortunately, this is a pretty long list so it's better to use an alias in your firewall rule.
2.) You can use the dns override and forward encrypted.google.com to a different ip address. It doesn't really block encrypted.google.com, but it sends the user to another site you trust - for example the address of opendns.com
To block using option #1, I ended up using the url table feature of the alias. It will read a text file at a URL and block all the IP addresses or networks that are listed. The nice thing is that there is a built-in cron job that re-reads the text file daily and updates the table in your firewall rules. In order to make sure the addresses were up to date in the text file, I wrote another little shell script the does an nslookup of whatever names you want (in this case encrypted.google.com) and writes their resolved ip addresses to a text file. I place the text file in my /usr/local/www directory so that it can be referenced by url in the alias. I just run my script 5 minutes before the built-in url update job runs.
This got me going on another track though... It seems that there are several encrypted search engines available that also provide image search capabilities. The ones I found were duckduckgo.com, ixquick.com and startpage.com. Unfortunately, these sites presented challenges with block option #1 because (for whatever reason) nslookup only returns one address for them - but it doesn't always return the same address! For example, you can do an nslookup multiple times in a 10 minute period and get multiple addresses back for ixquick.com! Because of that issue, I used option #2 to prevent access to these sites. Option #2 isn't perfect though - it would not stop someone if they were able to figure out one of the ip addresses of the site and browse there directly (via the ip address).