Linksys BEFSX41 Network Router User Manual


 
EtherFast
®
Cable/DSL Firewall Router with 4-Port Switch/VPN Endpoint
6766
Telnet A terminal
emulation protocol
commonly used on
Internet and
TCP/IP-based net-
works. It allows a
user at a terminal or
computer to log
onto a remote
device and run a
program.
SMTP (Simple
Mail Transfer
Protocol) The stan-
dard e-mail proto-
col on the Internet.
It is a TCP/IP pro-
tocol that defines
the message format
and the message transfer agent (MTA), which stores and forwards the mail.
DNS (Domain Name System) The way that Internet domain names are
located and translated into IP addresses. A domain name is a meaningful
and easy-to-remember “handle” for an Internet address.
TFTP (Trivial File Transfer Protocol) A version of the TCP/IP FTP proto-
col that has no directory or password capability.
Finger A UNIX command widely used on the Internet to find out infor-
mation about a particular user, such as a telephone number, whether the
user is currently logged on, and the last time the user was logged on. The
person being “fingered” must have placed his or her profile on the system
in order for the information to be available. Fingering requires entering the
full user@domain address.
Figure 7-38
Instant Broadband
®
Series
If you need to forward all ports to one PC, see the “DMZ Host” section.
To add a server using Forwarding:
1. Enter the name of the application in the appropriate Customized
Applications field.
2. Next to the name of the application, enter the number or range of the exter-
nal port(s) used by the server or Internet application in the Ext. Port col-
umn. Check with the Internet application software documentation for more
information.
3. On the same line, select the protocol UDP or TCP, or select both protocols.
4. Enter the IP address of the server that you want the Internet users to be able
to access. To find the IP address, go to “Appendix G: Finding the MAC
Address and IP Address for Your Ethernet Adapter.”
5. Check the Enable box to enable the services you have defined. Port Range
Forwarding will not function if the Enable button is left unchecked. This is
disabled (unchecked) by default.
6. Configure as many entries as needed—the Router supports up to ten ranges
of ports. Click the Apply button and Continue button when you are done.
UPnP Forwarding
The UPnP Forwarding screen, shown in Figure 7-38, displays preset applica-
tion settings as well as options for customization of port services for other
applications.
The Preset Applications are among the most widely used Internet applications.
They include the following:
FTP (File Transfer Protocol) A protocol used to transfer files over a
TCP/IP network (Internet, UNIX, etc.). For example, after developing the
HTML pages for a website on a local machine, they are typically uploaded
to the web server using FTP. FTP includes functions to log onto the net-
work, list directories, and copy files. FTP operations can be performed by
typing commands at a command prompt or via an FTP utility running under
a graphical interface such as Windows. FTP transfers can also be initiated
from within a web browser by entering the URL preceded by ftp://.