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2) Go to the internet connection created in step 1), change to the tab Failover and activate the option Use as backup connection.
3. ) Go to the menu Network → Connections → Network Connections and click on the "Pencil" symbol of the main internet connection (in this example the interface eth0 is used) to edit its settings.
4. ) Go to the tab Failover and select the internet connection created in step 1) as a Backup connection and add it via the "Plus" symbol.
5. Thereby the ) The configuration of the backup connection is now complete.