- Dynamic IP Address
Check this if your ISP uses dynamic IP address assignment. In this case, your IP address will change every time you establish a connection.
- Static IP Address
Check this if your ISP has given you a static IP address. In that case you will also need to fill in that address in the IP Address box, and any Subnet Mask if applicable. Ask your ISP if unsure. Dynamically assigned addresses are used in the huge majority if ISP's and leaving this checked will in most cases be the right choice.
- Auto-configure hostname from this IP
Select this option if you want KPPP to set the hostname and domain for your machine after a successful ppp connection.
This is done by querying the defined Domain Name Server with the IP assigned for the ppp link.
This option is useful for those stand-alone machines which want to use protocols such as talk, which require the hostname to be the same as your machine is known on the internet. It overrides the Domain Name option in the DNS section, and the machine defaults are restored to their original values when you close the ppp connection.
This option is not useful if you just want to connect to the internet and surf, check mail, or chat. It has the side-effect of disallowing any new connections to your X server - in other words, you can't open any more GUI programs.
Only turn this on if you are absolutely sure you need it.