ZyXEL Communications AMG1302-T series User Manual page 122

Chapter 8 Home Networking
Subnet Mask
Subnet masks determine the maximum number of possible hosts on a network. You can also use
subnet masks to divide one network into multiple sub-networks.
DHCP
A DHCP (Dynamic Host Configuration Protocol) server can assign your AMG1302/AMG1202-TSeries
an IP address, subnet mask, DNS and other routing information when it's turned on.
DNS
DNS (Domain Name System) is for mapping a domain name to its corresponding IP address and
vice versa. The DNS server is extremely important because without it, you must know the IP
address of a networking device before you can access it.
8.1.2.2 About UPnP
Identifying UPnP Devices
UPnP hardware is identified as an icon in the Network Connections folder (Windows XP). 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 in 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.
See the Chapter 11 on page 151
Cautions with UPnP
The automated nature of NAT traversal applications in establishing their own services and opening
firewall 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 device joins a network, it announces its presence with a multicast message. For
security reasons, the AMG1302/AMG1202-TSeries allows multicast messages on the LAN only.
All UPnP-enabled devices may communicate freely with each other without additional configuration.
Disable UPnP if this is not your intention.
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for more information on NAT.
AMG1302/AMG1202-TSeries User's Guide