Subject: lpr desktop printers
From: R Shapiro (reshapiro@mediaone.net)
Date: Tue Oct 31 2000 - 07:10:20 MST
I have a tcpdump capture of the the attempt to use an lpr desktop
printer in macos to spool print jobs to linux lpd. This is the case
that's generating a "protocol screwup" message from lpd. I updated my
lpr from 0.48 to 0.50, which didn't fix anything but does give a
little more context to the "screwup":
lpd[6960]: protocol screwup: ^Bepson-medres
"epson-medres" is the name of the linux printer queue in the macos
desktop printer. Here's the packet:
0000 00 00 00 00 00 01 00 00 de ad be ef 08 00 45 00 ........ ......E.
0010 00 36 e8 cc 40 00 ff 06 7e 8a c0 a8 01 02 18 da .6..@... ~.......
0020 39 e6 02 d1 02 03 9c 0d c2 4c 55 6c 63 c4 50 18 9....... .LUlc.P.
0030 80 00 a4 6c 00 00 02 65 70 73 6f 6e 2d 6d 65 64 ...l...e pson-med
0040 72 65 73 0a res.
The first 36 (hex) bytes are header (ethernet, ip, tcp). The packet
payload is as in the lpd error message -- a hex 02 (^B), then the name
of the queue -- followed by hex 0a. I don't have a lpd spec so I
don't know what the protocol problem is. Ethereal seems to think it's
valid (although it doesn't do anything with that final 0a).
Clearly there really is a protocol error here, and not, say, a
hardware error or a comm failure. I don't quite see how anyone could
have gotten around this. Are the people who have this scheme working
running MacOS 9.0.4 and lpr 0.50? If so, maybe one of those people
can provide *complete* details of their setup?
If anyone with lpd protocol expertise wants to look at the full trace,
let me know.
In the meantime I'm giving up on direct printing in mol. Using
appletalk seems ridiculously over-complicated, plus which I don't
really want to run appletalk anyway. For now I'll use the desktop
printer to generate .ps files, then copy the .ps files to linux and
print them with lpr.
-- reshapiro@mediaone.net
This archive was generated by hypermail 2a24 : Tue Oct 31 2000 - 08:18:19 MST