[cups] backend: open device failed for Laserjet 3010

[Tim Mooney]

In regard to: Re: [cups] backend: open device failed for Laserjet 3010,...:

> On 6/19/19 8:01 PM, Tim Mooney wrote:
>> 
>> Are all the printers running recent firmware? 
>
> We have upgraded one 3010 to version 20170106 07.250.2. According to
> HP's web page this is the most recent version. After a power cycle it
> still doesn't print.

For older printers like the 3010, my feeling is that you're best off
running the latest (probably "last") firmware available.

>> Are the two 3010 printers
>> configured the same as the other printers that are working?  Correct
>> network settings and access control settings (if appropriate)?
>> 
>
> Yes. As indicated before, all printers did work using cups 1.7.5-11+deb8u4
> and the hpijs pcl3 drivers version 3.14.6.

Well... that's not quite the answer to the question.  Yes, they all
worked before, but that doesn't actually imply that they were all
configured the same.  I'm mainly trying to rule out some setting on
the printer that might be impacting things.

>> Does nmap show the same set of open ports on the 3010s as on the working
>> printers?  There are probably better option sets to use with nmap, but
>> last time I needed to look at a printer, I used
>>
>>      sudo nmap -O -sV -sU -sS printerFQDN
>
> This takes an awful lot of time. Are there any specific ports or port ranges
> you have in mind?

Hmmm, it took 3 minutes and 42 seconds against an HP printer in the
subnet I'm in.  This is another case of just trying to verify that you're
getting identical port results between working and non-working.

> There are some messages in the log file saying

Which log file?

> E [26/Jun/2019:09:21:17 +0200] [Client 2] Unable to encrypt connection: A TLS 
> fatal alert has been received.
> E [26/Jun/2019:09:21:18 +0200] [Client 5] Unable to encrypt connection: A TLS 
> fatal alert has been received.
>
> Is this related?

I'm not sure, since I'm not certain which log file you're talking about,
but that looks like the CUPS error_log.  I wouldn't expect that to be
related to running nmap against the printer(s).

>> As a debugging point, does it make a difference if you use the hpcups
>> or PostScript PPD but use the 'socket' backend and port 9100 on the printer?
>
> Using port 9100 it worked (hooray).
>
> Would you recommend using port 9100 in general?

For HP printers, port 9100 usually works pretty reliably.  It has the
benefit of having been around for a really long time, and CUPS can send
jobs to the printer without having to use any of the hplip network code.

My preference these days would be to try IPP or IPPS first, and if that
doesn't work reliably, then try port 9100.

I personally would avoid anything having to do with hpijs.  It's been
deprecated for a long time.  Note that I'm only talking about hpijs, not
hplip in general.

Tim
-- 
Tim Mooney                                             Tim.Mooney at ndsu.edu
Enterprise Computing & Infrastructure                  701-231-1076 (Voice)
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