Troubleshoot dial-up modem problems on Mac
If your dial-up modem connects automatically
If the option to connect automatically is selected in the PPP pane of Network preferences, your computer connects to the internet every time you open an app or use a service that uses TCP/IP.
For example, if you have the automatic connection option selected and also have File Sharing turned on in Sharing preferences, your modem connects automatically as soon as you start up your computer.
Apps that may cause your modem to dial your ISP include Mail, Help Viewer, and your web browser.
You can set up your modem to not connect automatically.
On your Mac, choose Apple menu > System Preferences, then click Network.
Select your modem in the list at the left.
If your modem isn’t in the list, make sure your modem is connected to your computer (internally or externally), click the Add button at the bottom of the list, click the Interface pop-up menu, then choose Modem. Give your modem service a name, then click Create. Enter the settings for your PPP account. Check with your service provider if you’re not sure of the settings.
Click Advanced, then click PPP.
Deselect “Connect automatically when needed.”
You can select other connection settings, such as “Disconnect when user logs out” or “Disconnect when switching user accounts.”
If your dial-up modem doesn’t connect automatically
If you selected “Connect automatically when needed” in the PPP pane of Modem preferences, and your modem is not connecting when you use Mail, a web browser, or another app that requires a modem connection, you may need to reset the option.
For example, if you cancel a PPP connection attempt when the modem is dialing, or if you manually disconnect after an automatic connection, the option may fail, even if “Connect automatically when needed” is still selected.
To solve this problem, you can:
Reconnect manually.
Change any PPP setting, click Apply, then click Revert.
Put the computer to sleep, then wake it.
Change your network location.
Restart the computer.
If your dial-up modem keeps disconnecting from the internet
If you have to redial your dial-up modem internet connection after not using your Mac for a few moments, or reconnect your PPPoE connection, your Mac may be set to disconnect automatically when the connection is idle.
On your Mac, choose Apple menu > System Preferences, then click Network.
Select your modem port (internal or external) or your PPPoE configuration in the list at the left, then click Advanced.
Click PPP, then make sure “Prompt every __ minutes to maintain connection” is not selected, or if it is selected, increase the number of minutes that the computer can remain idle before disconnecting.
If you get an “authentication failed” message when dialing your ISP
If you receive an “authentication failed” message when you try to connect to the internet using a dial-up account to your ISP, your user name or password may be entered incorrectly in Network preferences.
On your Mac, choose Apple menu > System Preferences, then click Network.
Select your modem in the list at the left.
If you don’t see your modem in the list, make sure your modem is connected to your computer (internally or externally), click the Add button at the bottom of the list, click the Interface pop-up menu, then choose Modem. Give the service a name, then click Create. If there are no settings, enter the telephone number, account name, and password for the service.
Make sure your account name and password match those given to you by your ISP.
If your current password is not shown, carefully retype it to make sure it is correct. Don’t interpret the number of dots in the field as the number of characters in the current password; the numbers may not match.