D-Link Router DIR-120 User Manual

							DIR-120 Ethernet Broadband Router 
 D-Link DIR-120 User Manual                                                      
35 
DHCP Server Settings Dynamic Host Configuration Protocol (DHCP) allows the gateway to automatically obtain the IP address 
from a DHCP server on the service provider’s network. The service provider assigns a global IP address 
from a pool of addresses available to the service provider. Typically the IP address assigned has a long lease 
time, so it will likely be the same address each time the Router requests an IP address. If DHCP is not 
enabled on the Router, it is necessary for the user to assign a static IP address to each computer on your LAN. 
To set up DHCP for your LAN, first enable the Router as a DHCP server by clicking the Enable DHCP 
Server radio button in the window above. The next step is to set a range of IP addresses that you wish to 
allot to the devices on your LAN by entering a starting and ending number of addresses within the LAN 
subnet in the DHCP IP Address Range. This may be in a range from 2 to 254 (192.168.0.2 – 
192.168.0.254). Computers on your LAN will have an IP address within this range then automatically 
assigned to them. Finally, choose the DHCP Lease Time, which is the time the Server will set for devices 
using DHCP to re-request an IP Address. Clients authorized for DHCP will be listed in the Dynamic DHCP 
Client List near the bottom of the window. Click Save Settings to implement information set in this table. 
The DHCP Server is enabled by default. 
DHCP may also be statically configured as well. This method allows the router to assign the same IP address 
information to a specific computer on the network, defined by its MAC address. This computer will get the 
same DHCP implemented IP address information every time the computer is turned on and this IP address 
will be specific to that computer’s IP address on the local network. No other computer can be assigned this 
address. This is useful for computers on the LAN that are hosting applications such as HTTP or FTP. First, 
the user must enter the Host Name and the IP Address for that computer in the spaces provided. Next, the 
user must enter the MAC Address of the computer in the space provided. Click Save Settings to implement 
these static settings. 
 
 
 
 
 
 
DHCP Settings for LAN configuration menu 
  
						

							DIR-120 Ethernet Broadband Router 
 D-Link DIR-120 User Manual                                                      
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Printer Setup Use the Printer Setup Wizard to configure the Router’s USB Printer connection. To establish the connection to a USB equipped printer, click the Printer Setup link to view the 
Printer Setup Wizard launch menu. Follow the instructions below to install the printer driver on your computer. Some printers, especially very recent release printers, might 
require the Printer CD-ROM containing the printer driver that came with the printer. This procedure must be followed by any computer that will use the printer. 
To use a printer connected to the USB printer port on the DIR-120: 
1. Have the CD-ROM with the printer driver available, it might be needed for the installation.  
2. Power on the printer; follow the instructions included with the printer to plug in the power cable and turn the power on. 
3. Complete the USB connection from the DIR-120 USB to the USB port on the printer. Check the LED indicator on the DIR-120 front panel for the USB connection to 
make sure a physical connection is established. 
4. From the Printer Setup menu, click the Setup Wizard button to launch the Printer Setup Wizard. 
 
Printer Setup Wizard launch menu  
						

							DIR-120 Ethernet Broadband Router 
 D-Link DIR-120 User Manual                                                      
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5. The first Printer Setup Wizard menu lists the steps used for intallation. Click the Next button to detect the printer. 
 
 
 
 
 
 
 
 
  
						

							DIR-120 Ethernet Broadband Router 
 D-Link DIR-120 User Manual                                                      
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6. The printer should be detected immediately. The model name will be displayed if detected. If no printer is detected a warning tells you the printer installation cannot be 
completed. Check the cable connections and make sure the printer is powered on. Click Next if a printer is detected. 
 
 
 
 
 
 
 
 
 
  
						

							DIR-120 Ethernet Broadband Router 
 D-Link DIR-120 User Manual                                                      
39 
7. It is now necessary to install the correct printer driver on your computer. Click the Next button to launch the file. 
 
 
 
 
 
 
 
 
  
						

							DIR-120 Ethernet Broadband Router 
 D-Link DIR-120 User Manual                                                      
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8. A setup will launch or attempt to launch on your computer. Often the browser settings prevent the file from launching until permission is granted. This file must be 
executed to install the printer driver. In Windows Internet Explorer  permission can be granted to launch downloded application. See the example from Windows 
Internet Explorer as seen in XP below. If asked to insert the CD-ROM containing the printer driver, insert the CD-ROM in the CD-ROM drive of your computer and 
install the printer driver according to the instructions for the printer. 
 
 
Click the bar below the address bar in Windows 
Internet Explorer and Download File. The printer 
driver will be installed on your computer. If asked, 
insert the printer CD-ROM.  
Click Finish when the setup file has finished. 
The printer will now be displayed in the Printers 
and Faxes folder in Windows. 
Click security bar and 
select Download File 
option if IE security is 
preventing download.  
						

							DIR-120 Ethernet Broadband Router 
 D-Link DIR-120 User Manual                                                      
41 
Advanced Configuration 
The Advanced directory tab offers seven configuration menus, Port Forwarding, Application Rules, Access Control, Website Filter, Firewall Settings, Advanced 
Network, and QoS Engine. Click the corresponding link in the left panel of the window. Port Forwarding is the first menu listed and the first to appear when accessing the 
Advanced directory. 
 
Advanced menu links – Port Forwarding menu  
						

							DIR-120 Ethernet Broadband Router 
 D-Link DIR-120 User Manual                                                      
42 
Port Forwarding 
 
Port Forwarding Rules menu 
To enable an already existing Port Forwarding Rule, click on its corresponding 
checkbox and configure the appropriate fields listed below. To configure other 
Port Forwarding Rules for the Router, configure the following fields and click 
the Save Settings button at the top of the window. 
 To view the following window, click on the Advanced tab at the top of the window and 
then click the Port Forwarding button to the left. This window will allow remote users 
access to various services outside of their LAN through a public IP address, such as FTP 
(File Transfer Protocol) or HTTPS (Secure Web). After configuring the Router for these 
features, the Router will redirect these external services to an appropriate server on the users 
LAN. The Router has 13 pre-configured external services already set, but the user may add 
alternate services using the window above. The Port Forwarding Rules listed in the 
following window are: 
• FTP – File Transfer Protocol, used to transfer large files over the Internet 
• HTTP – HyperText Transfer Protocol, the basic protocol of the World Wide Web 
• HTTPS – HyperText Transfer Protocol Secure, the basic protocol of the World 
Wide Web with added security provided by the Secure Shell feature (SSH) 
• DNS – Domain Name Server, a server that translates website addresses into IP 
addresses 
• SMTP – Simple Mail Transfer Protocol, used to transmit e-mail messages between 
parties 
• POP3 – Post Office Protocol version 3, used to retrieve e-mail from a mail server 
• Telnet – A terminal emulation program used for remote configuration   
• IP Sec – IP Security, used for a secure transfer of information over the network. If 
one end of the transmission is using IPSec, so must the other end 
• PPTP – Point to Point Tunneling P
rotocol, used to transfer information securely 
between VPNs (Virtual Private Routers) 
• NetMeeting – An application that allows teleconferences over the Internet 
• DCS–1000 – A D-Link internet camera used for security monitoring 
• DCS–2000/DCS–5300 – A D-Link internet camera used for security monitoring 
• 2eye – A D-Link Broadband VideoPhone used for video conferencing 
These external services may be modified by clicking the corresponding checkbox. Though 
there are seven fields available to configure the Port Forwarding Rules, in most cases, only 
the IP address will be needed for implementation. For more information on configuring Port 
Forwarding Rules, otherwise known as Virtual Servers, see the window below, along with a 
brief explanation of the fields to be configured. 
  
						

							DIR-120 Ethernet Broadband Router 
 D-Link DIR-120 User Manual                                                      
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Application Rules 
 
Application Rule menu 
This window is used to configure applications that require multiple 
connections, such as Internet Telephony, video conferencing, and Internet 
gaming. The following window lists six Special Applications that commonly 
use more than one connection. To configure one of these applications, tick its 
corresponding checkbox and then modify the fields listed below the following 
figure. The user may add a new application by modifying the fields listed and 
then clicking the Save Settings button at the top of the window.   
						

							DIR-120 Ethernet Broadband Router 
 D-Link DIR-120 User Manual                                                      
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Access Control 
 
AC Filtering menu 
 
Access Control, or MAC filtering, is a basic security measure that should be used on 
any network that is exposed to a security risk. A packet filter system examines data 
packets and scrutinizes them in order to control network access. Filtering rules 
determine whether packets are passed through the Router from either side of the 
gateway. The rules are created and controlled by the network administrator and can be 
precisely defined. These rules are used to block access to the LAN from outside the 
network and/or to deny access to the WAN from within the network. The Router uses 
filtering rules to examine data packet headers for specific information. Packets passing 
through the Router that do not meet the criteria specified by the rule set are dropped. 
Effective implementation of packet filtering requires detailed knowledge of network 
services and communication protocols. An overly complicated filtering scheme can 
adversely affect the Router’s performance, while an inadequate set of rules may 
needlessly compromise security. 
This Router has two configurable methods for filtering and thus two ways of filtering 
packets received, MAC Filters and Website Filter (which is explained in the next 
section). MAC Filters All computers are uniquely identified by their MAC (Media Access Control) address. 
The following window will allow users to deny computers access to the Internet or 
only allow certain computers access to the Internet, based on their MAC address. To 
access this window, click the Advanced tab along the top of the configuration window, 
then the Access Control tab to the left hand side. 
To configure MAC filters, manually enter a MAC address to be filtered by ticking its 
corresponding checkbox and then configuring the desired fields on the window above. 
Select Turn MAC Filtering OFF, Turn MAC Filtering ON and ALLOW computers 
listed to access the network, and Turn MAC Filtering ON and DENY computers listed 
to access the network from the drop-down menu. When you are finished, click the 
Save Settin
gsbutton at the to
p of the window.