By default, pppd logs any warnings and error messages to syslog 's daemon facility. You have to add an entry to syslog.conf that redirects these messages to a file or even the console; otherwise, syslog simply discards them. The following entry sends all messages to /var/log/ppp-log:
daemon.* /var/log/ppp-log |
If your PPP setup doesn't work right away, you should look in this log
file. If the log messages don't help, you can also turn on extra
debugging output using the debug option. This output makes
pppd log the contents of all control packets sent
or received to syslog. All messages then go to the
daemon facility.
Finally, the most drastic way to check a problem is to enable kernel-level
debugging by invoking pppd with the kdebug
option. It is followed by a numeric argument that is the sum of the
following values: 1 for general debug messages, 2 for printing the contents of
all incoming HDLC frames, and 4 to make the driver print all outgoing
HDLC frames. To capture kernel debugging messages, you must either run
a syslogd daemon that reads the
/proc/kmsg file, or the klogd daemon.
Either of them directs kernel debugging to the syslog
kernel facility.