Using PPP or SLIP

The firewall supports the use of PPP or SLIP via a modem to connect to an Internet Service Provider. To use PPP, you need to specify ppp (for dialup) or pppd (for leased line) as the external interface on the System Setup Screen as well as configure some PPP-specific parameters. For SLIP, you should choose the sl0 interface as your external interface. The remaining parameters are configured in the SLIP/PPP Setup Screen (Figure 4.67), accessible from the System Setup Screen (Figure 4.3). The fields in this screen are:

  

Figure 4.67: The PPP Setup Screen

Serial Port

This toggle field lets you specify which serial port you wish to use for your connection.

Baud Rate

This toggle field lets you specify the baud rate of the serial port.

Phone Number

If you use a dial-up line rather than a leased line, you should enter the number to be dialled here. Include all digits to be dialled, such as prefixes for getting out through a PABX, or prefixes for accessing a long distance carrier. Many modems also allow you to use `,' to denote a short pause in the dialling sequence.

Idle Timeout

How long to wait in seconds before closing the connection when idle (the firewall supports demand-dial PPP). A value of zero disables the idle timeout.

Authent

The type of PPP authentication to be used, one of Basic, PAP or CHAP. Basic authentication corresponds to a normal password-based login, while the other mechanisms are more secure and prevent clear text transmission of the passord. Your ISP will usually determine what sort of authentication you should use.

Login Prompt

If you are using Basic authentication, you need to specify the last few letters of the login prompt issued by the remote side here. When the firewall sees these letters, it knows to attempt to send the user name to the remote. In most cases a suitable string will be one of `ame:' or `ogin:'.

User Name

The user id to use to log in to the peer.

Password Prompt

Similar to the login prompt, for Basic authentication you should enter a string here to use to detect the password prompt issues by the remote. In most cases `word:' will work.

Password

The password to use to authenticate the user