I replaced a 4003 switch with a 4503 within our network. The switch type change was not detected automatically and rediscovery did not change anything. I deleted the device but now discovery does not rediscover. It does show up as a cdp neighbor with two seed devices. It doesn't even show up as an unknown device. I've verified snmp config on the device in question. I've also reentered the snmp read only string within discovery options.