Problem with pppd

Enrico Lorenzetti (
Sun, 8 Jun 1997 11:29:35 +0200

I' ve got a strange and annoying problem with pppd on two Linux Boxes.
The first box has kernel version 2.0.30 with pppd 2.2.0f, ppp configured
a module (I had the same problem with pppd linked into the kernel), mgetty
1.0.0 and two Stallion Easy IO multiport boards.
Every now and then pppd doesn't seem to detect the loss of the carrier and
keeps running. Obviously at this point mgetty can't regain control of the
serial line and nobody can connect to that modem.
After a while (generally a few hours) the pppd process nearly chokes the
CPU (the top command has reported a 212% usage once, and generally reports
a 90+% CPU usage when this problem appears) and nobody can connect to any
Killing the process solves the problem.
The /AutoPPP/ option in login.config was:
/AutoPPP/ - - /usr/sbin/pppd auth -chap +pap login
lcp-echo-interval 30 lcp-echo-failure 5

adding lcp-echo-interval <X> lcp-echo-failure <Y> hasn't solved the
the options.ttyX file is (I've tried lot of configuration options but the
problems is still there)

# options for ppp dial-in
asyncmap 0
crtscts # hardware flow control
lock # UUCP style lock
netmask # netmask on connection
#silent # quietly wait for remote requests
#+pap # allow PAP validation
modem # use modem control lines (CD)
usehostname # use local host name for remote auth.
proxyarp # allow ARP resolution for client
#kdebug 7
#login # use /etc/passwd for remote
<LOC IP>:<REM IP> # use the modem09 address for now!!!

When the problem occurs the message file reports:

May 25 22:56:38 master pppd[16238]: pppd 2.2.0 started by <>, uid <>
May 25 22:56:38 master pppd[16238]: Using interface ppp9
May 25 22:56:38 master pppd[16238]: Connect: ppp9 <--> /dev/ttyE70
May 25 22:57:15 master pppd[16238]: Hangup (SIGHUP)

It doesn't seem to matter whether the user logs in or not, but and there
are no

May 25 22:57:42 master pppd[16238]: Modem hangup
May 25 22:57:42 master pppd[16238]: Connection terminated.
May 25 22:57:42 master pppd[16238]: Exit.


The modems are
Thundercom 33.600
the modem configuration string in mgetty.config is:

port ttyE0
data-only y
init-chat "" AT&F OK ATE0Q0V1 OK ATS0=0&C1&D2W1 OK

The same problem has recently started appearing on another Box with kernel
1.2.13 and pppd 2.1.2d, a cyclades 8 port adapter and mgetty 0.99.

Enrico Lorenzetti