🚀 go-pugleaf

I have observed that my pppd shuts down at a random interval from 
about 3 minutes to about 20 minutes after traffic ceases.  This 
is with Linux kernel 1.1.47 and pppd from ppp-2.1.2a.

I have not seen anything in the pppd manpage to say why this can 
happen, so can anyone comment on what I might be doing wrong?

The /var/adm/messages log shows:

Sep 24 09:06:21 linux pppd[1698]: remote IP address 158.152.251.194
Sep 24 09:17:17 linux pppd[1698]: Hangup (SIGHUP)
Sep 24 09:17:17 linux pppd[1698]: ipcp: down
Sep 24 09:17:17 linux pppd[1698]: Exit.

When there is plenty of traffic, this does not happen.  I have run 
over two hours of continuous traffic successfully in testing.

If I set "lcp-echo-interval 180", even though the peer does not seem 
to return the echos, this problem goes away, but I don't understand 
why.

Also if I then set "lcp-echo-failure 3", as expected, pppd shuts down 
communications after the specified number of failed echos, but the 
pppd process does not exit and the modem remains connected.  Moreover 
pppd will not then exit on any signal but SIGKILL, so my normal ppp 
shutdown script is ineffective.

The random hangup occurs when I start up pppd with:

# Start the main PPP connection (machine name from /etc/hosts).
/usr/lib/ppp/pppd connect /usr/local/sbin/demon.ppp \
    debug \
    crtscts modem defaultroute lock asyncmap 0x00000000 mru 576 mtu 576 \
    /dev/$port 38400

Regards and thanks in advance for any comments

John
-- 
John Phillips