UPnP
The Zyxel Device supports both UPnP and NAT-PMP to permit networking devices to discover each other and connect seamlessly.
Universal Plug and Play (UPnP) is a distributed, open networking standard that uses TCP/IP for simple peer-to-peer network connectivity between devices. A UPnP device can dynamically join a network, obtain an IP address, convey its capabilities and learn about other devices on the network. In turn, a device can leave a network smoothly and automatically when it is no longer in use. A gateway that supports UPnP is called Internet Gateway Device (IGD). The standardized Device Control Protocol (DCP) is defined by the UPnP Forum for IGDs to configure port mapping automatically.
NAT Port Mapping Protocol (NAT-PMP), introduced by Apple and implemented in current Apple products, is used as an alternative NAT traversal solution to the UPnP IGD protocol. NAT-PMP runs over UDP port 5351. NAT-PMP is much simpler than UPnP IGD and mainly designed for small home networks. It allows a client behind a NAT router to retrieve the router’s public IP address and port number and make them known to the peer device with which it wants to communicate. The client can automatically configure the NAT router to create a port mapping to allow the peer to contact it.
What You Need to Know
UPnP hardware is identified as an icon on the network folder (Windows 7). Each UPnP compatible device installed on your network will appear as a separate icon. Selecting the icon of a UPnP device will allow you to access the information and properties of that device.
NAT Traversal
UPnP NAT traversal automates the process of allowing an application to operate through NAT. UPnP network devices can automatically configure network addressing, announce their presence on the network to other UPnP devices and enable exchange of simple product and service descriptions. NAT traversal allows the following:
• Dynamic port mapping
• Learning public IP addresses
• Assigning lease times to mappings
Windows Messenger is an example of an application that supports NAT traversal and UPnP.
Cautions with UPnP and NAT-PMP
The automated nature of NAT traversal applications in establishing their own services and opening security policy ports may present network security issues. Network information and configuration may also be obtained and modified by users in some network environments.
When a UPnP or NAT-PMP device joins a network, it announces its presence with a multicast message. For security reasons, the Zyxel Device allows multicast messages on the LAN only.
All UPnP-enabled or NAT-PMP-enabled devices may communicate freely with each other without additional configuration. Disable UPnP or NAT-PMP if this is not your intention.
UPnP Screen
Use this screen to enable UPnP and NAT-PMP on your Zyxel Device.
The following table describes the fields in this screen.
Configuration > Network > UPnP
label | Description |
|---|
Enable UPnP | Select this check box to activate UPnP on the Zyxel Device. Be aware that anyone could use a UPnP application to open the web configurator's login screen without entering the Zyxel Device's IP address (although you must still enter the password to access the web configurator). |
Enable NAT-PMP | NAT Port Mapping Protocol (NAT-PMP) automates port forwarding to allow a computer in a private network (behind the Zyxel Device) to automatically configure the Zyxel Device to allow computers outside the private network to contact it. Select this check box to activate NAT-PMP on the Zyxel Device. Be aware that anyone could use a NAT-PMP application to open the web configurator's login screen without entering the Zyxel Device's IP address (although you must still enter the password to access the web configurator). |
Allow UPnP or NAT-PMP to pass through Firewall | Select this check box to allow traffic from UPnP-enabled or NAT-PMP-enabled applications to bypass the security policy.
Clear this check box to have the security policy block all UPnP or NAT-PMP application packets (for example, MSN packets). |
Outgoing WAN Interface | Select through which WAN interface(s) you want to send out traffic from UPnP-enabled or NAT-PMP-enabled applications. If the WAN interface you select loses its connection, the Zyxel Device attempts to use the other WAN interface. If the other WAN interface also does not work, the Zyxel Device drops outgoing packets from UPnP-enabled or NAT-PMP-enabled applications. |
Support LAN List | The Available list displays the name(s) of the internal interface(s) on which the Zyxel Device supports UPnP and/or NAT-PMP. To enable UPnP and/or NAT-PMP on an interface, you can double-click a single entry to move it or use the [Shift] or [Ctrl] key to select multiple entries and click the right arrow button to add to the Member list. To remove an interface, select the name(s) in the Member list and click the left arrow button. |
Apply | Click Apply to save your changes back to the Zyxel Device. |
Reset | Click Reset to return the screen to its last-saved settings. |