User's Guide

Chapter 13 Applications
EMG3435-Q20A User’s Guide
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Use the ip urlfilter customize actionFlags 8 [disable | enable] command to extend (or
not extend) the keyword blocking search to include the URL's complete filename.
NAT Tra ve rsa l
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 NAT chapter for more information on NAT.
Ca utio ns 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 EMG3435-Q20A 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.