What ports/services to allow?
I'm currently trying to set up a firewall using iptables. The only network connections I require are to dial up and browse the internet and maybe download using FTP, but I'm having trouble working out which ports I can and can't close. I've found numerous lists on the internet giving port numbers and the services that generally use them, but am not sure what services I need.
I've pretty much worked out how to use iptables and putting all the commands in a script shouldn't be too much of a problem. I want to set the INPUT chain to have a policy of DROP, but this requires me to add rules that ACCEPT packets from specific ports and so far I've not been able to do this.
What services and therefore ports are required for dialing up, browsing the internet and downloading with FTP?
What one Earth do the "auth" "time" and "x11" services do?
Thanks in advance for any help,