HP Color LaserJet CM1312 MFP Series - Software Technical Reference

IP discovery and rediscovery
This document discusses the features that function correctly, and those that don't, through the IP
discovery and rediscovery process for the product. Topics:
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Print and HP ToolboxFX
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Scan driver
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ScanTo application
Print and HP ToolboxFX
When the IPV6AddressEx is installed, the HP Port Monitor is also installed and the product’s IP address
is entered in the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Print\Monitors\HP Standard TCP/IP
Port\Ports\<port_name>\IPAddress
where <port_name> is the name of the port to which the printer-driver was installed. This port monitor
periodically checks for changes to the product’s IP address by using the Rediscovery library,
HPZJRD01.DLL. If a change is detected the registry entry is updated with the correct IP address. Both
the printer-driver and HP ToolboxFX use the IP address in this registry key to establish communication
with the product.
NOTE: Print, HP ToolboxFX, and scan driver rediscovery occurs only if the computer and the product
are on the same subnet mask.
Scan driver
When the HP Color LaserJet CM1312 MFP Series product is installed, the Scan co-installer determines
the IP address or hostname of the product and writes that information to the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{6BDD1FC6-810F-11D0-
BEC7-08002BE2092F}\0000\DeviceData\PortID
If the hostname can be obtained, it is written to this location; otherwise the IP address is written. The
scan driver uses this value to establish a connection to the product.
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Installed using hostname. If the hostname is written to the PortID registry key, when the product’s
IP address changes, this registry value does not change. It may take quite a bit of time for the
network routing tables to update the DNS servers with the new IP address for this hostname.
Scanning is inoperable while the DNS servers are being updated.
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Installed using IP address. If the IP address is written to the PortID registry key, then when the
product’s IP address changes, the registry value will only update if a scan had previously been
performed. Otherwise the user must either edit this value manually or run the FixScan utility to
update this value. Once a scan has been successfully completed, a registry key under the path
listed above, named PortData, will appear. This is a binary value which contains the MAC address
as well as some other data. If this key is present and the product’s IP address changes, then when
the user attempts a scan, the scan driver will initially use the PortID value to communicate with the
product. This will fail, but PortData value will be passed to the Rediscovery library, HPZJRD01.DLL,
to obtain the new IP address. Once the new IP address is obtained, it is written to the PortID registry
key.
ENWW IP discovery and rediscovery 247
Engineering Details