Informative error messages, 2
21.08.2005 17:24
Just spent 30 minutes solving another problem that I could fix in 30 seconds if I would only get a proper error message. Whoever wrote OS X printing system obviously thought that error handling is for the weak. I just found out that OS X will simply say "Print job stopped" (in exactly the same way as if someone stopped the job manually) instead of reporting an error if lpd daemon on a remote printer refuses the connection.
After checking all sorts of configuration options in OS X, adding and removing printers I finally run tcpdump to see what exactly is happening on the network. This is what I got:
17:36:01.864288 IP orion.printer > sen.1012: P 1:57(56) ack 5 win 1448 <nop,nop,timestamp 20706385 3602102236>
0x0000: 4500 006c d2e0 4000 4006 e450 c0a8 0102 E..l..@.@..P....
0x0010: c0a8 0108 0203 03f4 983c 26f2 d079 9481 .........<&..y..
0x0020: 8018 05a8 7bbb 0000 0101 080a 013b f451 ....{........;.Q
0x0030: d6b3 b7dc 6f72 696f 6e3a 206c 7064 3a20 ....orion:.lpd:.
0x0040: 596f 7572 2068 6f73 7420 646f 6573 206e Your.host.does.n
0x0050: 6f74 2068 6176 6520 6c69 6e65 2070 7269 ot.have.line.pri
0x0060: 6e74 6572 2061 6363 6573 730a nter.access.
Duh. One vi session of the /etc/hosts.lpd later, I could print again from my Powerbook, but how did OS X understand this as "Print job stopped" is beyond my comprehension.
