pppd with hdlc framing (sync mode)

[Matthias Ferdinand <mf%mferd.de@localhost>]

Hi,

is the HDLC line discipline in NetBSD working?

Called "pppd sync" in a terminal:
 Linux /
  FreeBSD6.0: ppp garbage on the screen
 NetBSD:      no output at all (while the log says LCP packets
                were sent)

This is with NetBSD4.0, /usr/sbin/pppd (2.4.4) or /usr/pkg/sbin/pppd 
(2.4.3nb2).

Background: I tried to connect to a remote L2TP server using rp-l2tp. ppp 
"sync" mode is required by rp-l2tp. When I start an l2tp connection in LAC 
mode, a tunnel and a call are successfully set up, and the remote side 
sends LCP configure requests. But the local pppd never sees any of these, 
and no local LCP configure requests ever make it to the wire.

I think the problem is not in rp-l2tp or pppd, but in NetBSD. If the "sync" 
option for pppd is removed, or pppd is replaced with a simple output 
generator, rp-l2tp sends ppp packets to the remote server (malformed 
because of the wrong encoding).

Do I need some other adjustments?

Best regards
Matthias Ferdinand