Very Computer

I'm having a problem with my PPP setup and I can't figure
out the solution.  As far as I can tell, everything is configured
correctly, except the connection keeps dying, and syslog is reporting
this:

Jun 27 10:52:30 xxxxx login: ROOT LOGIN ON tty1
Jun 27 10:54:12 xxxxx kernel: CSLIP: code copyright 1989 Regents of the University of California
Jun 27 10:54:14 xxxxx kernel: PPP: version 2.2.0 (dynamic channel allocation)
Jun 27 10:54:14 xxxxx kernel: PPP Dynamic channel allocation code copyright 1995 Caldera, Inc.
Jun 27 10:54:14 xxxxx kernel: PPP line discipline registered.
Jun 27 10:54:15 xxxxx kernel: registered device ppp0
Jun 27 10:54:17 xxxxx pppd[164]: pppd 2.2.0 started by root, uid 0
Jun 27 10:55:21 xxxxx pppd[164]: Serial connection established.
Jun 27 10:55:22 xxxxx pppd[164]: Using interface ppp0
Jun 27 10:55:22 xxxxx pppd[164]: Connect: ppp0 <--> /dev/cua3
Jun 27 10:55:25 xxxxx pppd[164]: Serial line is looped back.
Jun 27 10:55:25 xxxxx pppd[164]: Connection terminated.
Jun 27 10:55:26 xxxxx pppd[164]: Exit.

If anyone knows why I would be getting that "Serial line is looped back"
entry, and why it's dropping my carrier, I'd really like to know. I
know that device is correct, since my SLIP script works, but PPP doesn't.
Please reply via email, since I don't regularly monitor this group.

Thanks.

--

  Frontier Internet Operations and Support              |  lines
  http://www.frontiernet.net                             | suffice

I'm on a Win95 machine at the moment so I can't check file names... Have
a look in rc.inet1 or rc.inet2 in your /etc/rc.d directory (al least
Slackware has it there). If you're only using your machine for dial up
internet access the stuff for setting up network adaptors should be
commented out, leaving your localhost and loopback (my memory may be
slighlty faulty...) addresses.

: I'm having a problem with my PPP setup and I can't figure
: out the solution.  As far as I can tell, everything is configured
: correctly, except the connection keeps dying, and syslog is reporting
: this:

: Jun 27 10:55:22 xxxxx pppd[164]: Connect: ppp0 <--> /dev/cua3
: Jun 27 10:55:25 xxxxx pppd[164]: Serial line is looped back.

: If anyone knows why I would be getting that "Serial line is looped back"
: entry, and why it's dropping my carrier, I'd really like to know. I
: know that device is correct, since my SLIP script works, but PPP doesn't.
: Please reply via email, since I don't regularly monitor this group.

If you can make working link with slip its clear your modem works
right. So you must have problem with invoking pppd at the server end.
I'd bet 'serial line is looped back' message is caused your servers
shell is echoing back every byte your computer sends to it.

You can test the right way to invoke pppd at the server by dialing
manually, with minicom or the like, into your ISP and trying to
command it into ppp -mode according those advices your ISP has given
to you. You can recognize ppp -frames from lines of length 40 bytes
with lots of curly braces in them.

If you cannot command your server into ppp -mode at all, it might be
your ISP is configured to start ppp right after first LCP frame has
put into the line by your computer. This is nowadays very popular way
'cause Win95 does it like this by default. How to configure that in
linux can be seen at my homepage links to my ppp configurations.

--
Kalevi J Hautaniemi,      Marjatankatu 12,     33730 Tampere,  FINLAND.
******  http://www.sci.fi/~khmi/  *******  On air:  OH3FG, KO4BC ******

: : I'm having a problem with my PPP setup and I can't figure
: : out the solution.  As far as I can tell, everything is configured
: : correctly, except the connection keeps dying, and syslog is reporting
: : this:

: : Jun 27 10:55:22 xxxxx pppd[164]: Connect: ppp0 <--> /dev/cua3
: : Jun 27 10:55:25 xxxxx pppd[164]: Serial line is looped back.

: : If anyone knows why I would be getting that "Serial line is looped back"
: : entry, and why it's dropping my carrier, I'd really like to know. I
: : know that device is correct, since my SLIP script works, but PPP doesn't.
: : Please reply via email, since I don't regularly monitor this group.

: If you can make working link with slip its clear your modem works
: right. So you must have problem with invoking pppd at the server end.
: I'd bet 'serial line is looped back' message is caused your servers
: shell is echoing back every byte your computer sends to it.

: You can test the right way to invoke pppd at the server by dialing
: manually, with minicom or the like, into your ISP and trying to
: command it into ppp -mode according those advices your ISP has given
: to you. You can recognize ppp -frames from lines of length 40 bytes
: with lots of curly braces in them.

: If you cannot command your server into ppp -mode at all, it might be
: your ISP is configured to start ppp right after first LCP frame has
: put into the line by your computer. This is nowadays very popular way
: 'cause Win95 does it like this by default. How to configure that in
: linux can be seen at my homepage links to my ppp configurations.

I've seen exactly the same problem at home for incoming PPP connects, I
blame it on kernel 2.0.30 at the moment: the reason is that I have several
machines accessed by one dialup 'server', most are running old kernels,
2.0.13 - 2.0.29 and connects between the server and these work fine (both
ways, in and out), but outgoing connects to my home machine running 2.0.30
get this wretched Serial line is looped back message.... however connects
originating at my home machine work fine.

To get round this I have set the dialout server to use the -mn option to
pppd, this disable magic number processing... not really a long term
solution, but it works for now.

--
** David J Brown
** Radio Systems, University of Leicester
** Office: +44 116 252 2822
** Orange: +44 976 687217