Draytek Vigor2120n-plus User Manual page 274

Available settings are explained as follows:
Item
Enable UPNP Service
Default WAN
The reminder as regards concern about Firewall and UPnP
Can't work with Firewall Software
Enabling firewall applications on your PC may cause the UPnP function not working properly.
This is because these applications will block the accessing ability of some network ports.
Security Considerations
Activating the UPnP function on your network may incur some security threats. You should
consider carefully these risks before activating the UPnP function.

Some Microsoft operating systems have found out the UPnP weaknesses and hence you
need to ensure that you have applied the latest service packs and patches.

Non-privileged users can control some router functions, including removing and adding
port mappings.
The UPnP function dynamically adds port mappings on behalf of some UPnP-aware
applications. When the applications terminate abnormally, these mappings may not be
removed.
Vigor2120 Series User's Guide
Description
Accordingly, you can enable either the Connection Control
Service or Connection Status Service.
It is used to specify the WAN interface for applying such
function.
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