@Daro6825 Deco can work in router mode (default) as well as in AP mode. For better bandwidth using an ethernet backhaul is preferred - details.

@davidkasr In general these are the rules that you have to follow when positioning your RE. If that doesn't work for you and the distance between the router and RE is too long you may consider using...

@LH865 Make sure you're with the latest FW release for RE450. When you do that try the WPS method for adding the RE5450 to the OneMesh - video. If this method doesn't work either try this video guide.

@rrre220 This should not be a problem if you're the only person who knows the RE220 admin password. This password is visible only for the RE220 administrator account.

@ZEPPERION Make sure your FTP server is configured properly. If there's no active service on port 21 router may report it as closed from an external network. Use the stories I posted to see how to...

@ZEPPERION You can check an example for configuring a passive FTP service (Windows) - here. You can also check an example for configuring passive FTP service on Synology NAS - here.