I'll add in my 2 cents worth as well. If you aren't using the web based
administrative tools, disable that if it is enabled. I've had printers
taken down because they were listening on port 80, which one of the most
commonly scanned/probed ports. And, to make sure it isn't someone
maliciously trying to see if they can shut off your printers, enable an
administrative password if you are using a version that allows the
feature.... just to be sure it isn't someone accessing administrative
functions and turning off the network card from a distance.
/John R.
John A. Resotko
Head of Systems Administration
Michigan State University College of Law
email: [log in to unmask]
Phone: 517-432-6836
Fax: 517-432-6861
Current Chairperson of the
MSU Network Communications Community
>>> STeve Andre' <[log in to unmask]> 2/11/2008 1:45 PM >>>
In addidion to these good ideas, the printers should be in 35.15
space if not already, to prevent the outside world from fondling
them.
--STeve Andre'
On Monday 11 February 2008 13:28:14 Dennis Kelly wrote:
> I've seen it many years ago, but the quality of the JetDirect cards
> and their TCP/IP stacks have improved since then. If it is
happening
> to a number of different printers, it could likely be related to
> network traffic. Most of these stacks are single threaded and bomb
> out if they come across traffic that the firmware can't
> process/handle.
>
> Some recommendations:
>
> - Upgrade the firmware to the most recent version on all JetDirect
cards
>
> - Disable unused protocols, i.e. DLC, AppleTalk, Netware, FTP, HTTP,
> etc. Just make sure you actually don't use them.
>
> - Limit IP access to the systems that need to communicate directly
to
> the JetDirect card.
>
> - Check the traffic on the printer's network segment for anomalies
and
> find a way to prevent it.
>
> Hope this helps,
> dpk
>
> On Feb 11, 2008 11:02 AM, Laurence Bates <[log in to unmask]> wrote:
> > We are seeing a lot of HP Jetdirect printers disconnecting from
the
> > network today. It started this morning and many printers will
only
> > operate for a few minutes before they disconnect. Is anyone else
seeing
> > this? Any ideas?
> >
> >
> >
> >
> >
> >
> > Laurence A. Bates
> >
> > College of Education
> >
> > Michigan State University
> >
> > 217E Erickson Hall
> >
> > East Lansing
> >
> > MI 48824
> >
> > 517-355-2178
> >
> > [log in to unmask]
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