3Com WL-603 - Manual (Page 104)

102 C HAPTER 5: C ONFIGURING THE R OUTER
■ NAT — (Network Address Translation), NAT is the method by which
the Router shares the single IP address assigned by your ISP with the
computers on your network.
This function should only be disabled by advanced users, and if your
ISP assigns you multiple IP addresses or you need NAT disabled for an
advanced system configuration. If you have a single IP address and
you turn NAT off, the computers on your network will not be able to
access the Internet. Other problems may also occur.
■
IPSec NAT-T Pass-through — NAT-T (NAT Traversal) is an Internet Draft
proposed to IETF in order to help the problems associated with passing
IPsec traffic through NAT Routers. For NAT-T to work, both ends of the
connection need to support this function. Ensure that you select NAT-T
only if it is needed as it will reduce LAN-WAN throughput. This Router
supports NAT-T draft 2 implementation.
■
Universal Plug and Play — This is a technology that offers seamless
operation of voice messaging, video messaging, games, and other
applications that are Universal Plug and Play compliant. Some
applications require the Router's firewall to be configured in a specific
way to operate properly. This usually requires opening TCP and UDP
ports and in some instances setting trigger ports. An application that
is Universal Plug and Play compliant has the ability to communicate
with the Router, basically "telling" the Router which way it needs the
firewall configured. The Router ships with the Universal Plug and Play
feature disabled. If you are using any applications that are Universal
Plug and Play compliant, and want to take advantage of the Universal
Plug and Play features, you can enable this feature. Simply check the
Enable Universal Plug and Play checkbox. Click Apply to save the
change.
■ WAN Ping Blocking — Computer hackers use what is known as
"Pinging" to find potential victims on the Internet. By pinging a
specific IP address and receiving a response from the IP address, a
hacker can determine that something of interest might be there.
The Router can be set up so it will not respond to an Internet Control
Message Protocol (ICMP) Ping from the outside. This heightens the
level of security of your Router. To turn off the ping response, check
Block ICMP Ping and click Apply; the Router will not respond to an
ICMP ping from the Internet.