Lorenzo Quatrini schrieb:
I would setup a box with a proxy (eg. squid) and grant full internet access only to that box. On the other boxes either remove the default route, or block on the router/firewall internet access. On the proxy you can easily configure proxies for other services too (eg. pop3/imap) and filter out traffic from/to Internet at will (dansguardian/squidguard); on the pc's you just need to setup the proxy on yum.conf to enable yum updates and (if needed) configure the proxy on your browser, you email-client and so on. I'm still on my way to figure out how to implement a simple yum cache/proxy; as soon as I have news I'll let you know, as in that case you don't need anymore to setup squid and the proxy box will be really trivial to setup.
Thanks for your response, I'm trying to avoid to use a third machine (proxy or own repository) for my two machines - this would be too much effort. Both PC are in a university network, I will try to find out if there is already a proxy I can use.