[cups.bugs] problem with lpd reserve=on option

Michael Sweet mike at easysw.com
Tue Jul 13 06:54:43 PDT 2004

Anonymous wrote:
> ...
> Why would the CUPS people deliberately choose the default of
> reserve=no for this setting?????????? It had me stuffed for hours....

First, because most network printers don't care about the source
port - it was a shoddy excuse for security when LPR/LPD was
developed, and it is a shoddy excuse for security now.

Second, because users still insist on using LPD to talk to their
printers, even when the (faster, more reliable, less error prone)
printers support the socket or IPP methods, and since many users
have more than 11 network printers the queues would get stuffed
when they were all active (think traffic jam - only 11 jobs can
get through at any given time)

Third, the default setting is now "any" as of CUPS 1.1.21, so it
will, by default, use a priviledged source port from 1 to 1023,
which takes care of 99% of the remaining network printers and print
servers that want a priviledged port but don't restrict it to the
range of 721 to 731 defined in RFC 1179.

Finally, the CUPS documentation has a whole section on LPD options.

Michael Sweet, Easy Software Products           mike at easysw dot com
Printing Software for UNIX                       http://www.easysw.com

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