Secure a Proxy.

[NiGhtMarEs0nWax]

Hi,

I'm setting up Ubuntu Karmic on my sister's old computer for my nephew, he's quite young so my sister asked to install some content filtering. I'll first setup an OpenDNS account and I've installed and managed to get dansguardian and squid working on a virtual machine to try it out. so far it's working pretty well, but I need to secure it form the inside out.

I was thinking of blocking specific outbound ports so he could not bypass the proxy. because by default the firefox configuration can be easily changed. so I have a couple of questions.

1. is it possible to block outgoing ports on Ubuntu?
2. is that the best method?
3. is there anything else I should be aware of to prevent subversion?

lastly, this question is probably unrelated to this board but I've set up a cron job to update a dynamic ip with OpenDNS, the problem is that the password is in clear text in the user's crontab, can I play with permissions? is it possible to run the job under a root account and deny read/write access to a normal user?


Thanks!

[NiGhtMarEs0nWax]

bump please.