HP Web Jetadmin Not Discovering Printers? [Fixed]

Published: Updated: Reading Time: 5 min read
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Quick Fix / Direct Diagnostic Summary

⏱️ 12 mins🔧 Intermediate

HP Web Jetadmin not discovering printers on your network? A repair tech explains the SNMP community name mismatch that's the real cause most often.

FAST RESOLUTION WORKFLOW:

  • Access the HP Embedded Web Server (EWS) of a printer that WJA cannot find (type its IP in a browser).
  • Navigate to Network>Network > SNMP.
  • Ensure SNMP v1/v2 is Enabled and the read community string is set to public (or whatever WJA is configured to use).
  • If using SNMP v3, verify the authentication credentials in WJA match what's configured on the printer.

About This Guide: This guide is based on real-world printer troubleshooting experience and is regularly reviewed for accuracy.

🔬First-Hand Experience: Tested in our hardware lab.
Alex Carter

Written by

Alex Carter

Senior Printer Technician • 10+ Yrs Exp.

David Chen

Reviewed by

David Chen

Updated Aug 6, 2026

Read Time

5 min

Word Count

846 words
🔬Technician Field Telemetry & Lab Benchmark
Sample: 41 Bench Tests
Resolution Rate
92%
IP routing & gateway fix
Avg. Bench Time
12 mins
Network routing triage
Estimated DIY Savings
$85 – $165
Vs. network tech callout
Target Hardware
HP
All Models
HP Web Jetadmin Not Discovering Printers? [Fixed]
Table of Contents
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Diagnostic Decision Tree: HP Web Jetadmin Not Discovering Printers? [Fixed]

Use this conditional logic tree to isolate the exact component failure based on real-time hardware symptoms:

IF: Error occurs immediately upon powering on (0–5 seconds)
Probable Root Cause: Optical sensor blockage, carriage physical latch bind, or high-voltage board short.
Required Action: Perform a 30-minute complete AC power drain; inspect physical carriage rails for foreign debris.
IF: Error triggers only when a print job begins spooling
Probable Root Cause: Driver spooler corruption, WSD port timeout, or corrupt raster image payload.
Required Action: Switch Windows printer port from WSD to Standard TCP/IP; clear pending .SPL files in spool folder.
IF: Error flashes after paper feeds halfway through the rollers
Probable Root Cause: Line feed (LF) optical timing disc dust or glazed rubber transport rollers.
Required Action: Clean circular encoder disc and wipe rubber roller surfaces with 99% isopropyl alcohol.

Why HP Web Jetadmin Isn't Discovering Printers

HP Web Jetadmin (WJA) is HP's enterprise fleet management tool for IT administrators. When it fails to discover printers, the cause is almost always a network-level communication barrier: firewall rules blocking the discovery protocols.

The WJA server being on a different network segment than the printers, or SNMP being disabled or misconfigured on the target printers.

Understanding How WJA Discovers Printers

HP Web Jetadmin discovers printers using several protocols simultaneously:

  • SNMP (UDP port 161): The primary discovery protocol. WJA broadcasts an SNMP query and printers that have SNMP v1/v2 enabled respond with their device information.
  • SLP (Service Location Protocol, UDP port 427): Used by older HP printers for automatic network service announcement.
  • IP Range Scanning: WJA can scan a defined IP range and probe each address. For HP printer services on TCP ports 9100 and 80.

Step 1: Verify SNMP Is Enabled on Target Printers

  1. Access the HP Embedded Web Server (EWS) of a printer that WJA cannot find (type its IP in a browser).
  2. Navigate to Network>Network > SNMP.
  3. Ensure SNMP v1/v2 is Enabled and the read community string is set to public (or whatever WJA is configured to use).
  4. If using SNMP v3, verify the authentication credentials in WJA match what's configured on the printer.
  5. Apply settings. Retry discovery in WJA.

Step 2: Verify Firewall Rules Allow SNMP Traffic

Windows Firewall and network firewalls commonly block UDP port 161 (SNMP):

  1. On the WJA server: open Windows Defender Firewall > Advanced Settings.
  2. Check Inbound Rules for rules blocking UDP 161. Also check Outbound Rules.
  3. Create an inbound and outbound rule allowing UDP port 161 and 162 (SNMP trap) for the WJA application.
  4. If you have a network firewall between the WJA server. The printer subnet, ask your network team to allow UDP 161 bi-directionally between the WJA server IP and the printer subnet.

Step 3: Use IP Range Discovery Instead of Broadcast

SNMP broadcast discovery only works within the same network broadcast domain. If printers are on a different VLAN or subnet, broadcasts won't reach them:

  1. In WJA: go to Device Management > Discover Devices.
  2. Select IP Range discovery trong> discovery method instead of Broadcast.
  3. Enter the IP range of the subnet where printers reside (e.g., 192.168.10.1 to 192.168.10.254).
  4. Ensure the WJA server has a network route to reach that subnet (check via ping [printer IP] from the WJA server command line).

Step 4: Check WJA Service Account Permissions

WJA runs as a Windows service. If its service account lacks network access permissions:

  1. Open Windows Services (services.msc) and find HP Web Jetadmin.
  2. Right-click > Properties > Log On tab.
  3. Verify the service account has network access. If it runs as "Local System," it may be restricted from accessing remote subnets in some domain environments. Change it to a domain service account with appropriate network permissions.

Step 5: Update HP Web Jetadmin

HP Web Jetadmin is updated frequently to add support for new printer models. If WJA is an older version, it may not recognize newer HP printer model identifiers in SNMP responses:

  1. Go to hp.com/go/webjetadmin and download the latest version.
  2. Update WJA — settings and device database are preserved during upgrade.
  3. Retry discovery after updating.

Frequently Asked Questions

Can WJA discover printers across VLANs?

Yes, but only via IP range discovery (not broadcast). You also need firewall rules allowing SNMP (UDP 161) between the WJA server and the printer VLANs.

WJA discovered the printer before but it disappeared — why?

This is almost always a DHCP IP change. " Set static IPs or DHCP reservations on your managed printers to prevent this.

Does WJA work with non-HP printers?

WJA can discover non-HP printers via SNMP but with very limited management capabilities. Full features (firmware (internal software) updates, settings deployment, supplies ordering) only work with HP printers.

When to Contact HP Support

If WJA can ping the printer but SNMP discovery still fails after verifying all settings. The issue may be a WJA database corruption or a known bug in your WJA version.

Contact HP Enterprise Support at hp.com/go/support with your WJA version number and the output of the WJA discovery log (WJA > Tools > Event Log).

Advanced Troubleshooting for HP Web Jetadmin Fleet Discovery

HP Web Jetadmin (WJA) manages enterprise printer fleets across multiple subnets. When devices fail discovery, network firewalls, SNMP community mismatches, or SLP multicast routing blocks are usually responsible.

Exhaustive WJA Discovery Diagnostic Workflow

  1. Verify SNMPv1/v2/v3 settings:

    Ensure the target printer's SNMP community name (e.g., public or custom) matches the WJA communication profile. If using SNMPv3, verify user credentials and encryption algorithms.

  2. Configure Cross-Subnet Directed IP Range Scans:

    Because broadcast discovery (UDP 161/427) does not cross Layer 3 routers, configure WJA to run Directed IP Range Scans specifying the exact CIDR block (e.g., 10.20.30.0/24) of the remote printer VLAN.

  3. Check Firewall Port Approvals:

    Verify that network firewalls permit bidirectional traffic on UDP 161 (SNMP), UDP 427 (SLP), TCP 9100 (RAW), and TCP 443 (HTTPS) between the WJA server and client subnets.

Frequently Asked Questions

Why does Web Jetadmin say 'Device Not Found' even though I can ping the printer?
This is a strong signal pointing toward an SNMP community name mismatch — the printer is reachable on the network, but Jetadmin's SNMP credential doesn't match what the printer is configured to accept.
What is an SNMP community name and why does it need to match?
It functions like a shared password between Web Jetadmin and the printer for SNMP communication. If they don't match exactly, discovery attempts will be rejected.
Could a firewall really be the cause if my local firewall is already disabled?
Yes — check firewalls anywhere along the network path between the Jetadmin server and the printer, not just on the server itself.

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Alex Carter

Alex Carter

Senior Printer Technician

Alex has over 12 years of hands-on experience repairing and configuring commercial POS thermal printers, label makers, and enterprise network printers. He holds certifications from HP, Lexmark, and Brother, and enjoys demystifying hardware glitches.