I have some printers that when show problem and we have to replace, the MAC-to-IP mapping remains at core and even when deleting manually it doens't work. If we use a different IP address at same network it works perfectly. After a lot of time (believe about 4 hours that is the time those informations are holded at core) it works normally but never at first moment.
My Equipments: Core: 6506 and Edge: 4509.
Equipment that shows problem: Barcode Printer Toshiba SX5T-7S12-QQ.
What happnes is that when for some reason the printer is replaced for an exactly same model, even if I clear the MAC from Core switches it doesn't reply or remap the new MAC for the same IP address used. If I use a new address it works perfectly. If I wait some hours (4 to refresh the CAM at Core) it works.
the problem is that printer are mapped at application and changing IP address isn't an easy action.