Canon imagePROGRAF GP-4000 - Manual (Page 793)

If not, select it to enable bidirectional support.
Check 9 Make sure security software's firewall is off.
If your security software's firewall is on, a message may appear warning you that Canon software is attempting
to access the network. If this warning message appears, set security software to always allow access.
If you are using any programs that switch between network environments, check their settings.
Check 10 If printer is connected to an AirPort Base Station via LAN, make sure you use
alphanumeric characters for network identifier (SSID). (macOS)
If the problem is not resolved, redo setup.
• For Windows: •
Perform setup using the Setup CD-ROM or from Setup Guide.
• For macOS: •
Perform setup from Setup Guide.
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