About FirewallA firewall is a function of the security software installed in the computer or operation system forcomputer, and is a system that is designed to prevent unauthorized access to a network.Precautions When a Firewall Function is Enabled• A firewall function may limit communications between a printer and a computer. This may disableprinter setup and communications.• During the printer setup, you may be prompted to enable or disable communications, dependingon the firewall function of the security software or operation system. If so, choose to enablecommunications.• When using IJ Network Tool, you may be prompted to enable or disable communications,depending on the firewall function of the security software. If so, choose to enablecommunications.• If you cannot set up the printer, temporarily disable the firewall function of the security softwareor operation system.ImportantIf you disabled the firewall function, disconnect your network from the Internet.• Some applications (like the network configuration software) override firewall settings. Check theapplication's settings beforehand.• If the printer you use is set to Get IP address automatically, the IP address changes every timethe printer connects to the network. This may disable printer setup and communications,depending on the firewall settings. In this case, either change the firewall settings or assign afixed IP address to the printer. An IP address can be set using IJ Network Tool.Changing the Settings in the Wireless LAN SheetChanging the Settings in the Wired LAN SheetWhen assigning a fixed IP address to the printer, you will need to specify an IP address withwhich the computer can communicate.NoteFor the operation system firewall settings or the security software firewall settings, refer to theinstruction manual of the computer or software, or contact its manufacturer.