The original question was:
>>I have several HP laserjet printers which I am using TCP/IP to make my
>>connection to the network and printing to them. Generally this works
except >>at times to printer seem to disappear from the net. I can't print
to them, I >>can't ping them it's like they don't exist. Usually if I turn
the printers >>off and on then they will work again for a while. Any ideas
or suggestions?
Mike Crowley sent a better and correct answer to my problem. Here it is
followed by how it helped me.
>(This is a bit vague and probably has some errors of detail, but
>the ideas behind this might be something to consider. It is also
>based on a hardware configuration that you might not have and
>would therefore be irrelevant. Just guessing....)
>
>If you have the printers behind a switch which learns a limited number
>of addresses, I understand that there are conditions under which
>a printer that is not sending out any packets for a while can be
>lost to the network. If the switch is set so that it does not
>flood all ports with packets destined for an unknown MAC address,
>a packet with that unknown MAC address will not reach the printer.
>It will be functionally gone. Power cycling would cause it to
>send something out, thereby causing its MAC address to be back in
>the switch's table.
>
>The solution, if this is the problem, is to load the printer MAC
>address into the switch as a permanent address on that port.
This was indeed my problem. we have two ethernet switches and when the printers
disappeared I checked the switch databases and sure enough their MAC
addresses were not in them. I put the MAC address in and made them
permanant and haven't had a problem since. I was close with the timeout
issue but I was looking on
the wrong piece of equipment.
Paul Crittenden
System Manager
Simpson College
e-mail: crittend_at_storm.simpson.edu
Received on Tue Dec 16 1997 - 22:11:39 NZDT