SNMP printer discovery documentation?

[Michael Sweet]

John A. Murdie wrote:
> I'm learning about what is new in 1.2.*, particularly the SNMP
> printer discovery facility. Is there any documentation about this
> from the point of view of a day-to-day systems manager? (E.g. what
> does the discovery find, and need I configure the printers in any way
> to allow it to do this?; when does the discovery run if automated?;
> should I run it myself when I add or remove a printer - and, if so,
> how?; how I can I override what it finds, if that is ever necessary?
> etc.)

Aside from the cups-snmp.conf man page and the snmp.conf reference
page (both accessible from the web interface), there isn't a whole
lot of extra documentation available aside from the comments in
backend/snmp.c.

The SNMP backend currently broadcasts an SNMP "get" request for the
HOST-RESOURCES-MIB::hrDeviceType.1 OID.

For any responses to this query, we make sure that it reports the
printer type OID and then send out a query to the responder for
the HOST-RESOURCES-MIB::hrDeviceDescr.1 OID which is used for the
printer make and model (unless we find additional information via
IPP).

The SNMP query itself lasts no more than 3 seconds, and times out
after 1 second of inactivity.

Once we have collected addresses of printer devices, we then probe
those addresses on ports 631, 9100, and then 515.

For port 631, we query the printer via Get-Printer-Attributes
requests on common URIs to determine whether the printer really
supports IPP and to get the "real" make and model, 1284 device ID,
and so forth.  The IPP probe is setup to use non-blocking IO and
to timeout, however it tests several device URIs before giving
up...

So far, the IPP probe seems to be the cause of slow operation or
hangups, particularly with Kyocera network devices.  As we don't
have a Kyocera network printer in our lab, we're depending on users
(like you ;) to help us collect data and track down the ultimate
problem.

-- 
______________________________________________________________________
Michael Sweet, Easy Software Products           mike at easysw dot com
Internet Printing and Publishing Software        http://www.easysw.com