OKI B432 and MB472 print POST /ipp/print HTTP/1.1: how to stop random printing over USB

Last Updated on 11.08.2026 by DriverNew

If an OKI B432 or MB472 spontaneously prints several sheets containing POST /ipp/print HTTP/1.1, lines such as Windows Internet Print Provider and Host: localhost, the cause is usually not the document, toner cartridge or printer mechanism. This text may be printed incorrectly during system-level data exchange between Windows and a device connected via USB.

The problem often appears immediately after the printer is turned on, the computer starts, or the USB cable is reconnected. The printer may output several pages even though the user has not sent anything to print. Sometimes the normal print job then disappears from the queue, remains in it, or the device changes to an “Offline” state.

Which models this guide applies to

Cases of printing the POST /ipp/print HTTP/1.1 header have been confirmed on devices from the OKI B432 and OKI MB472 families. The main instructions are intended for the following models:

• OKI B432dn and B432dnw;
• OKI MB472dn and MB472dnw.

The same checks also apply to related models that use the same PCL6 packages:

• OKI B412dn, B512dn, ES4132dn and ES5112dn;
• OKI MB492dn, MB562dnw, ES4172LP MFP, ES4192 MFP, ES5162 MFP and ES5162LP MFP.

For a related model, use this guide only if the spontaneously printed sheet contains the same POST /ipp/print and Windows Internet Print Provider lines. A PCL XL error, a PostScript message or random characters printed only with a specific document require different troubleshooting.

Make sure this is specifically an IPP over USB error

The numbers and individual lines may differ, but the beginning of the printed page usually looks like this:

POST /ipp/print HTTP/1.1
Connection: Keep-Alive
Content-Type: application/ipp
User-Agent: Windows Internet Print Provider
Content-Length: 571
Host: localhost

The Content-Length value is not an error code and may be different. What matters is the combination of POST /ipp/print, the mention of application/ipp and the Windows Internet Print Provider line.

Why the printer prints a Windows system request

Some devices support both standard USB printing and IPP over USB. Windows uses IPP to detect printer capabilities and create a modern print queue. If the operating system encounters an error, the system HTTP/IPP request may be sent not to its intended interface but into the normal print data stream. The printer does not recognize it as system communication and prints the text on paper.

This is why replacing the toner cartridge, resetting counters and cleaning the printing mechanism do not help. Reinstalling the same driver without updating Windows may also provide only temporary results: the system request can reappear after the next startup or USB reconnection.

Step 1. Stop the unwanted printing and clear the queue

1. Turn off the printer using the power button.
2. Disconnect the USB cable from the computer.
3. Do not turn the printer back on until the queue has been cleared and Windows has been restarted.

Windows 11

1. Open Settings.
2. Go to Bluetooth & devices > Printers & scanners.
3. Select the OKI queue from which the printing occurred.
4. Click Open print queue.
5. Cancel all remaining jobs. If a command to cancel all documents is available, use it.

Windows 10

1. Open Settings.
2. Go to Devices > Printers & scanners.
3. Select the OKI printer and click Open queue.
4. Cancel all jobs in the list.

If a job cannot be removed

1. Press Win + R.
2. Enter services.msc and press Enter.
3. Find the Print Spooler service.
4. Right-click it and select Restart.
5. Open the queue again and cancel the remaining job.

Do not disable Print Spooler permanently. This service is required for normal printing, and permanently disabling it does not fix the cause of the incorrect IPP request.

Step 2. Install all current Windows updates

This is the main step. The issue has occurred in different releases of Windows 10 and Windows 11 and has been fixed through cumulative updates. Do not try to find only one old KB number: a newer cumulative update already includes earlier fixes.

Windows 11

1. Leave the printer turned off and the USB cable disconnected.
2. Open Settings > Windows Update.
3. Click Check for updates.
4. Install the available Windows cumulative update and all other required fixes.
5. If the system requests a restart, click Restart now.
6. After signing back in to Windows, open Windows Update again and check for updates once more.
7. Continue until there are no pending cumulative updates or restart-required messages.

Windows 10

1. Leave the printer turned off and disconnect the USB cable.
2. Open Settings > Update & Security > Windows Update.
3. Click Check for updates.
4. Install the available cumulative update.
5. Restart the computer even if Windows does not do so automatically.
6. Check for updates again and install the remaining required fixes.

Step 3. Check the USB connection after updating

1. After all updates have finished, restart the computer completely.
2. Connect the USB cable directly to the computer. During testing, do not use a docking station, monitor with USB, switch or external hub.
3. Use a working USB 2.0 cable no longer than 5 m; a length of 2 m or less is preferred.
4. Turn on the OKI printer and wait until it reaches the ready state.
5. Connect the free end of the USB cable to the printer.
6. Wait one or two minutes while Windows detects the device.
7. Print one test page from the printer properties.
8. For an additional test, disconnect the cable, wait at least five seconds and reconnect it once.

If POST /ipp/print pages no longer appear and the test page prints normally, no further changes are required. Do not disable IPP or reinstall a queue that is working correctly.

Step 4. Check which driver and port the queue uses

After the issue, Windows may leave several queues for the same device. One queue may use the OKI driver, while another uses the Microsoft IPP Class Driver. Do not remove all printers indiscriminately: first determine which driver and port are assigned to the problematic queue.

Windows 11

1. Open Settings > Bluetooth & devices > Printers & scanners.
2. Select the problematic OKI queue.
3. Open Printer properties. If this command is not available on the current screen, open More printer settings or More devices and printer settings, then right-click the printer and select Printer properties.
4. Go to the Advanced tab and write down the name in the Driver field.
5. Open the Ports tab and find the row with the selected check box.

Windows 10

1. Open Settings > Devices > Printers & scanners.
2. Select the problematic queue and click Manage.
3. Click Printer properties.
4. On the Advanced tab, write down the driver name.
5. On the Ports tab, check the port with the selected check box.

Which values should be selected

If the Microsoft IPP Class Driver is shown in the driver field and you did not intentionally configure IPP printing, remove only that queue and install the OKI PCL6 driver. Do not remove the Microsoft system driver from the Windows driver store and do not manually remove USBIPP devices in Device Manager.

The presence of a USBIPP component inside the official OKI package is normal by itself. It is not malware and does not prove that the installation is incorrect. The problem is caused by how the system request is handled, not by a single INF file that needs to be removed.

Step 5. Reinstall the official OKI PCL6 driver

Perform the reinstallation if the queue uses Microsoft IPP Class Driver, a driver for another model, an incorrect port, or if normal printing was not restored after updating Windows.

Remove only the problematic queue

1. Turn off the printer and disconnect the USB cable.
2. Open the Printers & scanners list.
3. Select the queue that uses the incorrect driver or is recreated every time the printer is connected.
4. Click Remove and confirm the action.
5. Do not remove working network queues, other printers or fax drivers.
6. Restart the computer.

Select the file for your model

Both packages are intended for Windows 10 and Windows 11 and contain versions for the supported system architectures. Do not extract the EXE for a normal installation: run the downloaded file as an installer.

Install the driver for a USB connection

1. Make sure the USB cable is still disconnected from the computer.
2. Double-click the downloaded EXE file.
3. If a User Account Control prompt appears, click Yes.
4. Select the installer interface language.
5. Read and accept the license agreement.
6. Select your printer model.
7. Select the USB connection connection type.
8. Select the recommended installation. For an MFP, it may additionally install the scanner driver and utility software.
9. When the installer asks you to connect the device, turn on the printer, wait until it reaches the ready state and connect it to the computer using a direct USB cable.
10. Do not connect the printer before the installer prompts you if the screen explicitly states that the cable must remain disconnected.
11. Select the detected model, complete the installation and restart the computer.
12. Open the properties of the new queue and print a test page.

If the installer does not find the device, wait at least five seconds after disconnecting the cable, connect it to another USB port directly on the computer and repeat the search. Do not change the cable, driver, port and IPP settings all at the same time: perform a separate test after each change.

Step 6. Switch the printer to a Standard TCP/IP Port

If the computer and printer can be connected to the same router or network switch, a TCP/IP network port is the most convenient workaround. With this configuration, PCL6 jobs are sent to the device’s IP address and do not depend on IPP over USB.

Connect the printer to the network and find its IP address

1. Connect the printer to the router or switch using an Ethernet cable.
2. Turn on the printer and wait until it is ready.
3. On a B412, B432, B512, ES4132 or ES5112, open PRINT INFO on the control panel, select NETWORK and press OK.
4. On an MB472, MB492, MB562 or related MFP, press SETTING, select Reports > System > Network Information, then confirm printing.
5. Find IPv4 Address on the printed page. A working address usually looks like 192.168.1.25 or 10.0.0.25.
6. If 0.0.0.0 is shown or the address starts with 169.254, the printer has not received a valid address from the router. Check the Ethernet cable and network port before adding the queue.

It is advisable to reserve the assigned address for the printer in the router’s DHCP settings. If the address changes, the Standard TCP/IP Port created in Windows will no longer find the device.

Add the printer by IP address in Windows 11

1. Open Settings > Bluetooth & devices > Printers & scanners.
2. Click Add device.
3. Wait for Add manually to appear and click it.
4. Select Add a printer using an IP address or hostname.
5. In the device type field, select TCP/IP Device.
6. Enter the IPv4 address from the printed page.
7. If an option for automatically querying the printer and selecting the driver is available, clear it. This helps prevent Windows from recreating a WSD or Microsoft IPP queue.
8. When the driver list appears, select the exact OKI … (PCL6) model.
9. Complete the wizard and print a test page.

Add the printer by IP address in Windows 10

1. Open Settings > Devices > Printers & scanners.
2. Click Add a printer or scanner.
3. After the search, click The printer that I want isn’t listed.
4. Select Add a printer using a TCP/IP address or hostname.
5. Select TCP/IP Device and enter the printer’s IPv4 address.
6. Clear the option for automatically querying the printer if it is displayed.
7. Select the PCL6 driver for your OKI model.
8. Complete the installation and print a test page.

If the wizard asks for additional port information

1. Select the device type Custom.
2. Open Settings.
3. Select the RAW protocol.
4. Set the port number to 9100.
5. Finish creating the port.

Remove the old USB or IPP queue only after printing successfully through the new TCP/IP port. This allows you to return quickly to the previous configuration if another network problem is discovered.

Step 7. Use a temporary startup sequence

If updating Windows or switching to a network connection is not currently possible, the following startup sequence may sometimes help:

1. Shut down the computer completely.
2. Connect the OKI printer to the computer via USB.
3. Turn on the printer and wait until it reaches the ready state.
4. Only then turn on the computer.
5. Test printing one document.

This is a temporary workaround, not a fix for the cause. After the startup sequence changes again or the cable is reconnected, the system pages may reappear.

Step 8. Disable IPP on the printer if other methods are unavailable

Disabling IPP should be used only as a last resort: update Windows first and try a Standard TCP/IP Port. To change this setting, the device must be temporarily connected to the network even if it will later continue working via USB.

1. Connect the printer by Ethernet cable to the same network as the computer.
2. Print the NETWORK page on the B432 or Network Information on the MB472 using the instructions above.
3. Enter the printer’s IPv4 address in the browser address bar, for example http://192.168.1.25.
4. Open the device administrator login.
5. Enter the administrator account name if requested and the printer’s current password. Do not use an assumed factory password if it has already been changed.
6. If the initial setup wizard appears after signing in, select Skip to proceed to the settings.
7. Open Admin Setup > Network Menu > IPP. In some versions of the web interface, the section is named Network Setup > IPP.
8. Change IPP from Enable to Disable.
9. Click Submit at the bottom of the page.
10. Wait for the printer to restart.
11. Restart the computer and test USB printing through the OKI PCL6 queue.

To restore AirPrint or normal IPP printing, open the web interface again and set IPP to Enable.

If POST /ipp/print pages continue to print

After completing the main steps, determine whether the error depends on the computer, cable or device itself.

1. Make sure Windows was actually restarted after the latest cumulative update.
2. Check the Advanced tab: the queue should use the PCL6 driver for the exact OKI model.
3. Check the Ports tab: a USB queue should use a virtual USB port, while a network queue should use a Standard TCP/IP Port.
4. Disconnect other USB printers and scanners during testing.
5. Replace the cable with a known-good USB 2.0 cable that is 2 m or shorter.
6. Connect the cable to another USB port on the computer without using a hub.
7. Test the printer on another computer with fully updated Windows.

Methods you should not use

In most cases, spontaneous printing of POST /ipp/print HTTP/1.1 stops after installing the current Windows cumulative update. If the USB connection remains unstable, install the exact OKI PCL6 driver and create a queue using a Standard TCP/IP Port. Disable IPP on the device itself only after considering the impact on AirPrint and other network printing methods.