PPP Configuration

Options

The /etc/ppp/options file contains the dial-in configuration.

This file needs to contain the following information:

auth +chap -pap crtscts proxyarp lock
ms-dns 123.456.789.123
name dialin
10.254.100.1:10.254.100.1

You will need to change the ms-dns 123.456.789.123 IP address to point to the correct DNS server (normally the IP address of eth0, if a DNS server is running on the host).

You may also need to change the 10.254.100.1:10.254.100.1 address range to ensure you do not have ssh host file conflicts when dialing in.

Chap Secrets

The Chap Secrets file contains our username and password. You will need the program genpass, to create a cryptographically secure password.

This file should contain information like below:

"pppusername" "dialin" "123456" "10.254.100.2"

You will need to change the "pppusername" and "123456" sections, to provide a good username (normally "companynameppp") and a secure password. You may also want to change the "10.254.100.2" IP address to use a different IP address, but this is not required by default.

Please note the following characters cannot be used in ppp passwords:

• ' ' - space

• ' ' - tab

• '#' - pound sign

• '@' - at sign

• '\' - backslash (next character is interpreted as function ie: \n = newline)

• '"' - double quote

ttyS0 Options

The /etc/ppp/options.ttyS0 file will contain the IP address range which the host will use as local PPP addresses. This file will need to look like this:

10.254.100.1:10.254.100.1

You may want to change the address range if this conflicts with an address already in use, or if you require something different for another reason. However, the default is commonly sufficient.