Solved: Windows Print Server printing across vlans

jmustico · ‎02-20-2007

We have a 4507R core connected to remote 4503s. each 4503 is connected via 2 1gig fiber ports set up in a etherchannel. Each floor has 2 4503s. Each floor is a seperate vlan and subnet.

Issue: Our print servers are located on vlan 254. Users send print jobs from ports associated with any other vlan and they hit the queue just fine. The jobs don't make it to the printer until the printer has been power cycled. Within a few minutes, the printer goes "dead" again until it is power cycled.

Is there a requirement to have a print server per vlan that I'm not aware of?

Is there an IOS command to allow access to multiple vlans so the printer ports will see info coming from vlan 254?

PCs don't seem to be affected in any way, and it is NOT just 1 type of printer. Multiple models, multiple manufacturers.

Thanks

Jon Marshall · ‎02-20-2007

John

Off the top of my head

1) Check your switch logs to make sure you aren't seeing any duplicate mac address messages.

2) More likely if things work fine when the printers and the print server are in the same vlan is sounds like they could be using some sort of broadcast/multicast to talk to each other rather than unicast. This would have to be a setting on the printers somewhere.

HTH

Jon

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Jon Marshall · ‎02-20-2007

Hi

There is no requirement for a print server per vlan.

Can you clients ping the print server. Can you print server ping the printers.

Are you routing between vlans on your 4507R ?

Unless you are using access-lists somewhere and basic network connectivty is fine this doesn't seem to be a network issue.

HTH

Jon

jmustico · ‎02-20-2007

Appreciate the quick response.

We can ping the print servers regardless of what vlan we are on. We can also ping the printers. The weird thing is, is that every once in a while, we ping the printer, and after a couple timeouts, it will start to reply, and then it will start to print. Its almost like the printer nic is going to "sleep". This didn't start happening to any of the printers until we started implementing vlans.

What's also weird is that we have 1 remote site with 2 vlans. We experienced something very similar. In the end, we reassigned the printer ports to the same vlan as the print server and things started working fine. Why I'm trying to find a better answer is that we move PCs and printers around here like a faucet runs water!

Any idea? Even a shot in the dark might help!

John

Jon Marshall · ‎02-20-2007

John

Off the top of my head

1) Check your switch logs to make sure you aren't seeing any duplicate mac address messages.

2) More likely if things work fine when the printers and the print server are in the same vlan is sounds like they could be using some sort of broadcast/multicast to talk to each other rather than unicast. This would have to be a setting on the printers somewhere.

HTH

Jon

hoogen_82 · ‎02-20-2007

Not sure about my soln but just try a ip helper-address on your vlan interface. I do know its only for your UDP but just try its harmless :)

HTH

Hoogen

Do let me know if soln worked out.

jmustico · ‎02-20-2007

I'll check it out. We are, by default, setting switchport block multicast AND unicast on all ports to cut down on unnecessary traffic. I wasn't aware that the printers would talk over multicast or unicast. I'll let you know.

Thanks again,

John

jmustico · ‎02-20-2007

ALL -

Based on above advise, I removed the "switchport block unicast" command from one of the ports and wala, it started printing. There must, however, be an easier way that tracking down each individual printer port. As I said, we move around here like water thru a faucet!!

Jon - Thanks again. Great lead!

John

rolf.fischer_2 · ‎02-20-2007

>The weird thing is, is that every once in a while, we ping the printer, and after a couple timeouts, it will start to reply, and then it will start to print.

Sounds like the entry in the CAM-table ages out (it normally does after 5 minutes) and has to be relearned. This is not unusual for a printer's entry because a printer doesn't "talk" very much. You could assign the printers MAC-Addresses statically by configuration to the interfaces. I'm not sure if it helps but it maybe worth a try.

But I'd also agree to the postings saying server and printer might communicate via Broadcast - that's also not unusual.

jmustico · ‎02-20-2007

Thanks for the input. I'll give it a shot. Gonna look into previous post's advice first and let you all know.