Although PPP support is provided in almost all Linux distributions but it is still
better to check whether it is present on your system. You can use checkconfig or, better
still, look into the /usr/sbin directory and locate PPP binaries with the command
ls -al ppp*
If you get a listing like this:
-rwxr-xr-x 1 root root 3438 2005-05-28 14:56 ppp-go* -rwxr-xr-x 1 root bin 1787 2004-02-26 21:36 ppp-off* lrwxrwxrwx 1 root root 6 2005-05-28 14:17 ppp-on -> ppp-go* lrwxrwxrwx 1 root root 7 2005-05-28 14:17 ppp-stop -> ppp-off* -rwxr-xr-x 1 root bin 346812 2004-02-26 21:36 pppd* -rwxr-xr-x 1 root bin 37916 2004-02-26 21:36 pppdump* -rwxr-xr-x 1 root bin 25936 2003-03-02 22:05 pppoe* -rwxr-xr-x 1 root bin 22308 2003-03-02 22:05 pppoe-relay* -rwxr-xr-x 1 root bin 35084 2003-03-02 22:05 pppoe-server* -rwxr-xr-x 1 root bin 12028 2003-03-02 22:05 pppoe-sniff* -rwxr-xr-x 1 root bin 58527 2004-02-26 21:36 pppsetup* -rwxr-xr-x 1 root bin 9192 2004-02-26 21:36 pppstats*
then PPP support is definitely present.
Similarly, look into /etc/ppp directory, which contains the PPP options file
and some other files configuring PPP:
-rw------- 1 root root 78 2004-02-26 21:36 chap-secrets -rw------- 1 root root 1625 2005-05-28 14:35 connect-errors -rw-r--r-- 1 root root 938 2003-03-02 22:04 firewall-masq -rw-r--r-- 1 root root 836 2003-03-02 22:04 firewall-standalone -rwxr-xr-x 1 root root 1208 2005-05-28 14:56 ip-down* -rwxr-xr-x 1 root root 1208 2005-05-28 14:29 ip-down.OLD* -rwxr-xr-x 1 root root 1945 2005-05-28 14:56 ip-up* -rwxr-xr-x 1 root root 1945 2005-05-28 14:29 ip-up.OLD* -rw------- 1 root root 541 2005-05-28 14:58 options -rw------- 1 root root 656 2005-05-28 14:56 options.demand -rw-r--r-- 1 root root 9975 2005-05-28 11:21 options.old -rw------- 1 root root 216 2005-05-28 14:56 pap-secrets drwxr-xr-x 2 root root 4096 2003-03-02 22:05 plugins/ -rw-r--r-- 1 root root 104 2003-03-02 22:04 pppoe-server-options -rw-r--r-- 1 root root 4562 2003-03-02 22:04 pppoe.conf -rw------- 1 root root 129 2005-05-28 15:12 pppscript -rw------- 1 root root 8941 2005-05-28 14:56 pppsetup.txt
For the sake of safety do copy your original options file to a file options.old
so that you can revert back to your original setup should you have troubles.
See the PPP HOWTO Chapter 10 for more information on PPP support in the Linux kernel.