Subject: Re: SLIP/serial driver Problem?
To: Robert Elz <kre@munnari.OZ.AU>
From: Frederick Bruckman <>
List: tech-net
Date: 02/03/2004 12:14:56
On Tue, 3 Feb 2004, Robert Elz wrote:

> With PPP, I haven't figured out how to get it to start, without going
> through the PPP config process (LCP negotiations, authentication, and
> all that).   None of that was relevant for me, as I had (note past tense)
> a hard wired line (copper from home to work with a modem on each end,
> with my end configured to ignore DTR) - nothing ever changed, all I
> wanted was a silent IP pipe (like an ethernet would be).   SLIP
> provided that.  When I switched to PPP, I could never make it work again.
> Maybe it was just the implementation, but to get the LCP stuff to
> negotiate, meant I needed to cause the other end to notice that my
> end had gone away - which generally meant, causing my modem to drop
> carrier to the remote modem for a while, so the remote end would
> see the hangup, then go through the modem re-sync, and go back to
> expecting PPP startup, which was the only thing I could make my end
> do (no data frames till that was done).
> There must be a better way, mustn't there?   What is it?

See "lcp-echo-failure" and "lcp-echo-interval", also "holdoff" and
"lcp-restart", so one end doesn't go mad while the other end is down.

If you've started with "persist" but not "demand", you can also
initiate renegotiation by sending a SIGHUP -- "/etc/rc.d/pppd hup".
(With "demand", or without "persist", it would just hang up.)