Windows LPR byte counting mismatch — queue setting that actually works
Joe B.
Expert ★★★★★ 27,853 satisfied customers
Specialities: Windows print servers, Standard TCP/IP Port, LPR/LPD, RAW 9100, SMB/IPP queues
Windows LPR byte counting mismatch — Standard TCP/IP Port, queue name, LPR byte counting enabled/disabled
Technician
Quick scan first so I don’t guess:
• Which OS is acting as the **print server** — Windows Server 2012 R2 / 2016 / 2019 / 2022, or Windows 10/11 Pro acting as a “server”?
• Is the port type on the problem queue **Standard TCP/IP Port → LPR** to a device/print appliance, or are you printing **direct to printer** from the client?
• Symptoms: jobs stuck on **Spooling**, disappear with “Printed” but nothing comes out, **multi-page jobs truncated**, or Event Viewer logs **“bytes printed” smaller than spool file**?
• Any explicit errors like “LPR byte counting mismatch”, “Win32 error 5 / access denied”, or “The printer did not respond” in the System log?
Technician
In LPR mode the **Windows Standard TCP/IP Port monitor** tells the LPD server, “I’m about to send N bytes.” If your port has **“LPR Byte Counting Enabled”** set differently from what the device expects, or the **queue name** isn’t exactly right, you get:
• Jobs that disappear right after Spooling
• “Job printed” in the Windows queue but **nothing at the device**
• Event log entries where the **spool file size** and **bytes printed** don’t match
Plan so we fix it once:
1) Confirm this queue really needs **LPR** (not RAW 9100 / IPP).
2) Check the **Standard TCP/IP Port** properties: Protocol = LPR, correct **Queue Name**, and **LPR Byte Counting Enabled** set as the print server vendor recommends.
3) Flush stuck jobs, restart the **Print Spooler** service, and re-test with a small 1-page PDF.
4) If LPR stays flaky, create an alternate **RAW 9100** or **IPP** queue where possible, and keep LPR only for the system that truly requires it.
Technician
On the **print server** (not just your admin PC):
1) Open Print Management or Control Panel → Devices and Printers → right-click the shared printer → Printer properties.
2) Go to the Ports tab → highlight the port used by this queue (often named after the printer IP) → click Configure Port….
3) Under Protocol, choose LPR (not RAW). In LPR Settings:
• Enter the exact **Queue Name** the device or print appliance expects (common defaults:
lp, raw, print, or a vendor-specific name shown in its web UI).• Toggle **LPR Byte Counting Enabled**: if the vendor docs say “enable LPR byte counting”, tick it; if they warn it causes stalls, leave it unchecked.
4) Click OK, then print a tiny test job (1-page PDF) and watch the queue: does it go from Spooling → Printing → “Printed” with the page actually coming out?
Technician
Step 2 — Rebuild the LPR port cleanly with the correct settings
To get rid of any old mis-matched configuration:
1) On the Ports tab click Add Port… → Standard TCP/IP Port → New Port… and walk through the wizard.
2) Enter the **IP or hostname** of the print box, let Windows detect it, then choose Custom → Settings….
3) Under Protocol select LPR.
4) In **LPR Settings**:
• Set Queue Name exactly as required (e.g.
lp, print, or the name listed in the server’s “LPR queue” page).• Check **LPR Byte Counting Enabled** if the vendor wants strict byte counting (many release solutions and print management systems do).
5) Back in Printer properties, switch the queue to this **newly created port** and untick any old port you aren’t using.
This way the **Standard TCP/IP Port** is in a known-good state: correct host, correct queue name, and **LPR byte counting** aligned with the device.
Technician
Step 3 — Tune the Windows spooler and data type for LPR
1) In **Printer properties → Advanced**:
• Ensure **Spool print documents so program finishes printing faster** is selected.
• For testing, uncheck **Enable advanced printing features** so the driver sends **RAW** instead of EMF where possible (some LPR/LPD servers handle RAW better).
2) Click Print Processor… and pick the vendor’s recommended processor; if unsure, test **WinPrint → RAW**.
3) Clear all jobs from the queue, then restart the **Print Spooler** service:
•
net stop spooler → delete any files in C:\Windows\System32\spool\PRINTERS → net start spooler.4) Try that 10-page PDF again. If it still truncates, we either need to:
• Flip **LPR Byte Counting Enabled** back the other way and re-test, or
• Stop using LPR from Windows and send jobs to this device via **RAW 9100** or **IPP** if it supports those protocols.
Technician
Step 4 — Build a “stable” LPR queue that matches the appliance
Here’s the pattern we use in production environments:
• Keep a dedicated **LPR queue** on the Windows print server with:
– Protocol = LPR, correct **Queue Name**, **LPR Byte Counting Enabled** = ON (so the appliance can bill correctly).
– **WinPrint → RAW** print processor where supported.
– **Advanced → Enable advanced printing features** disabled for reliability.
• Make sure the print management appliance is not adding its own transformations that change job size mid-stream (e.g. re-compression or watermarking), or it will clash with byte counting.
• If possible, configure the vendor system so Windows is the only LPR client and end-user devices print to the Windows queue via SMB/IPP. That way the Windows LPR port is a single, predictable path instead of hundreds of client PCs talking LPR directly.
Technician
Step 5 — Clean up SNMP, firewall and bidi to avoid future LPR issues
• In Configure Port… for the Standard TCP/IP Port:
– If the device is a smart MFP that supports SNMP, leave **SNMP Status Enabled** with the correct community and index so Windows can detect “Offline”.
– If you see random “Offline” / “Error” while the printer is actually up, temporarily disable **SNMP Status Enabled** to see if status polling is interfering with the LPR sessions.
• On the **General → Preferences** and **Advanced** tabs, uncheck **Enable bidirectional support** if the driver is older or you see hangs when querying status.
• Confirm that firewalls between the print server and device allow **TCP 515** (LPR) and don’t DPI-inspect or time out long-running connections too aggressively.
These don’t directly change **byte counting**, but they often fix the “prints 3 jobs then pauses” pattern that shows up with LPR.
Technician
• For a plain **Windows print server → printer** scenario, Microsoft and most vendors prefer **Standard TCP/IP Port in RAW mode (port 9100)** — simpler protocol, fewer **LPR byte counting mismatch** headaches.
• Use **LPR** only when something in the chain requires an LPR/LPD queue: Unix systems, certain print management servers, legacy devices, etc.
• If you must keep LPR, you’ve already done the right hardening: correct **queue name**, stable **byte counting** setting, RAW data type, and clean spooler/port config.
For many shops we keep **two queues**: a “normal” RAW queue for general printing, and a separate **LPR queue** tailored for the external solution. Users never see the LPR queue directly — only the system that needs it does.
Technician
Quick answer: the accepted fix
Accepted fix when you hit a Windows LPR byte counting mismatch: on the print server, edit the Standard TCP/IP Port, set Protocol to LPR, enter the correct Queue Name, and toggle LPR Byte Counting Enabled to match the device’s requirements. Disable advanced printing features, use a RAW data type, clear the spooler, and retest with a small job. If LPR remains unstable and the device supports it, create a separate RAW 9100 or IPP queue and keep LPR only for systems that require it.
Why Windows shows LPR byte counting mismatch (LPR/LPD protocol & queue name)
The **LPR/LPD protocol** is simple but picky. Windows sends print data over TCP 515 and, with LPR byte counting enabled, tells the server the exact job size up front. If the **Standard TCP/IP Port** has the wrong queue name, incorrect **byte counting** setting, or a driver that changes the data length mid-stream, the LPD server may close the connection early. Windows then logs a **“byte counting mismatch”** and reports fewer bytes printed than the size of the spool file. Aligning the **LPR queue name**, byte counting flag, and print processor (often RAW) is the key to stable LPR printing on Windows 10/11 and Windows Server.
How to verify your LPR queue and byte counting are correct
To confirm your **LPR queue setting actually works**, start with a 1–2 page PDF. In the Windows queue, watch the job move from Spooling to Printing to Printed while the device outputs every page. Then check Event Viewer → System for the print event: the **spool file size** should closely match the reported **bytes printed**. If multi-page documents truncate or jobs vanish, re-open Configure Port… for the Standard TCP/IP Port and test the opposite **LPR Byte Counting Enabled** setting, double-check the **Queue Name**, and ensure the device or print appliance is listening on TCP 515 for that queue. For long-term stability, consider a separate **RAW 9100 queue** for normal users and reserve LPR for the specific integration that needs it.
LPR byte counting — quick troubleshooting tips
Most “LPR byte counting mismatch” errors come down to three things: queue name, byte counting flag, or data type.
Quick path: on the Windows print server, open the printer’s Standard TCP/IP Port → set Protocol to LPR → enter the exact Queue Name from the printer or print appliance → toggle LPR Byte Counting Enabled as recommended by the vendor → disable advanced printing features and use a RAW print processor → clear the spooler and retest. If your device supports **RAW 9100** or **IPP**, create a second queue using those protocols to avoid relying on LPR for day-to-day printing.
Disclaimer: This information is AI-generated and intended for general guidance only. For advice specific to your environment, please consult a verified expert on Whizz-Tech before making decisions.
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FAQ
What does an LPR byte counting mismatch mean in Windows?
It means the **Windows LPR client** and the **LPD server** disagree on how many bytes were in the job. The spooler sends a size value when LPR Byte Counting Enabled is on; if the device receives fewer or more bytes than expected, it may drop the job or stop part-way through. This shows up as **“Size of spool file” vs “Number of bytes printed”** mismatches in Event Viewer and often causes **missing or truncated prints**.
Should I enable or disable “LPR Byte Counting Enabled” on the port?
It depends on the **printer or print appliance**. Many modern print servers, pull-print and accounting systems require **LPR byte counting enabled** so they can bill correctly and detect completed jobs. Some older or simpler devices prefer it off for performance. If vendor documentation exists, follow it; otherwise test both settings on a small multi-page job and keep the one that produces consistent output with no errors.
Windows LPR vs RAW 9100 — which is better for a print server?
For most Windows environments a **Standard TCP/IP Port in RAW mode (port 9100)** is simpler and more reliable — fewer protocol quirks, no **LPR byte counting mismatch**, and better driver support. Keep **LPR/LPD** only when a specific integration requires it (Unix systems, certain print management servers, or devices that only expose an LPR queue). You can run both: a RAW queue for users, and a dedicated LPR queue tuned for the external system.
Why do my LPR jobs disappear from the Windows queue with no error?
Common causes are a wrong **LPR queue name**, incorrect **LPR byte counting** flag, firewall issues on **TCP 515**, or an LPD server that closes idle connections. Windows marks the job as Printed, but the device never accepts it. Fixes: verify the queue name against the device UI, set **LPR Byte Counting Enabled** as recommended, confirm port 515 is open, and consider disabling SNMP status or bidirectional support on the port if status polling is causing instability.
Sources
- Microsoft — Standard TCP/IP port monitor for Windows print servers
- TP-Link — How to enable the “LPR Byte Counting” option in Windows
- MyQ — LPR queue and LPR Byte Counting Enabled for Windows ports
Filed under: Printers
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