ZD421 and ZD621 Desktop Printer User Guide

Printer Connectivity Issues

Issue	Possible Cause	Recommended Solution
My printer reassigns a new IP address to the print server after the printer has been off for a while.	The settings for your network are causing the network to reassign a new IP address.	If the changing IP addresses cause issues for you, follow these steps to assign a static IP address to the printer: Find out what values need to be assigned to the IP address, subnet mask, and gateway for your print server (wired, wireless, or both). Change the appropriate IP protocol value to PERMANENT. Change the values for the IP address, subnet mask, and gateway for the appropriate print server to what you want them to remain. Reset the network by touching Menu Connection Networks Reset Network and then touching the check mark to save the changes.
My printer does not obtain an IP address while trying to connect via LAN/Ethernet.	The cable is not plugged in correctly.	Check that both ends of the cable are connected properly.
	The printer is not configured correctly (usually for DHCP).	Check the Wired IP Protocol setting. It should match your network environment.
I cannot change the wired, wireless, or Bluetooth settings on my printer.	The printer is in Protected Mode, which prevents these settings from being updated without the Protected Mode password. You cannot change these settings through the front panel.	You will need the Protected Mode password to change the settings via JSON commands. For more information, refer to the Zebra Link-OS PrintSecure Printer Administration Guide.
	For printers purchased in the EMEA region after August 1, 2025, many connectivity options are disabled by default.	For additional information and a configuration wizard, go to zebra.com/asr.
I manually entered a wireless IP address, subnet, and gateway on my printer, but it won’t connect to my wireless network. Protected Mode is not enabled.	The printer’s network must be reset after values are changed.	Reset the network by touching Menu Connection Networks Reset Network and then touching the check mark to save the changes.
	An ESSID value was not specified.	For a wireless connection, specify the ESSID value that matches the value used by your wireless router using the following Set/Get/Do command: ! U1 setvar "wlan.essid" "value" where "value" is the ESSID (sometimes called a network SSID) for your router. You can look on the back of your router for a sticker with the router’s default information. If the information has been changed from the default, check with your network administrator for the ESSID value to use. Reset the network by touching Menu Connection Networks Reset Network and then touching the checkmark to save the changes.
	The ESSID or another value was incorrect.	Print a network configuration label and verify that your values are correct. Make corrections as necessary. Reset the network by touching Menu Connection Networks Reset Network and then touching the check mark to save the changes.