Canon MF8580Cdw User Manual page 573

The machine dials up to an unintended connection destination (if a dialup router is connected to a network).
If a dialup router does not need to pass broadcast packets, set the dialup router so that the broadcast packets will not pass. If
the dialup router needs to pass broadcast packets, check whether the settings are correct.
If a DNS server is located in an external network, set the IP address to be connected, not the host name, even if connecting to
the devices that are on the network that is connected to the machine.
If a DNS server is located on a network that is connected to the machine and the information about the devices that are
connected to an external network is registered to the DNS server, check whether the settings are correct.
When the machine cannot connect to the wireless LAN
Check the status of your computer.
Have the settings of the computer and the wireless router been completed?
Are the cables of the wireless router (including the power cord and LAN cable) correctly plugged in?
Is the wireless router turned on?
If the problem persists even after checking the above:
Turn off the devices, and then turn them on again.
Wait for a while, and try again to connect to the network.
Check whether the machine is turned ON.
If the machine is turned ON, turn it OFF, and then turn it back ON.
Check the installation site of the machine and the wireless router.
Is the machine too far from the wireless router?
Are there any obstacles such as walls between the machine and the wireless router?
Are there any appliances such as microwave ovens or digital cordless phones that emit radio waves near the
machine?
Perform one of the following settings again.
Setting Up Connection Using WPS Push Button Mode
Setting Up Connection Using WPS PIN Code Mode
Setting Up Connection by Selecting a Wireless Router
Setting Up Connection by Specifying Detailed Settings
NOTE
When you need to manually set up the connection
If the wireless router is set as described below, manually enter all the required information for the wireless LAN connection
( Setting Up Connection by Specifying Detailed Settings).
*
ANY connection refusal is activated.
The WEP key that was automatically generated (hexadecimal) is selected.
*
A function in which the wireless router refuses the connection if the SSID on the device to be connected is set to "ANY" or is blank.
When you need to change the settings of the wireless router
If the wireless router is set as described below, change the settings of the router.
The MAC address packet filtering is set.