3Com Router WL-537 User Manual

							
Advanced85
SecuritySelect Security  to display the Security screen.
Security Screen
The Internet connects millions of computer users throughout the world. 
The vast majority of th e computer users on the Internet are friendly and 
have no intention of breaking into,  stealing from, or damaging your 
network. However, there are hack ers who may try to break into your 
network. The options in the  Security tab features help you to protect your 
network.
Advanced Settings
The Advanced Sett ings section of the Security screen displays the 
following options:
■Enable universal plug and pl ay - Universal plug and play allows 
compatible software to read and  change some the Router’s firewall 
settings. This reduces the configuration required but lessens your 
control of the Router’s firewall.
Check on the check box  to enable this feature, and then select  Apply. 
						

							
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3Com recommends that you leave this feature disabled for maximum 
security.
■Allow PING from the Internet - PING is a utility, which is used to 
determine whether a device is active  at the specified IP address. PING 
is normally used to test the ph ysical connection between two devices, 
to ensure that everything is working correctly. 
By default the Router has PING disabled in order to make the device 
more difficult to find on th e Internet and less prone to attack. 
Check on the check box to enable this feature, and then select  Save.
3Com recommends that you leave this feature disabled for maximum 
security.
■Disable 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 the network. Only disable NAT 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 
your turn NAT off, the computers on your network will not be able to 
access the Internet. Other problems may also occur.
Check on the check box to disable NAT, and then select  Save.
3Com recommends that you leave this  feature enabled for maximum 
security.
Enabling Remote Administration
It is possible to administer the Ro uter remotely. Select one of the 
following options for remote administration:
■Disable Remote Administration  - This option is set as default.
■Enable administration from a single Internet Host -  Only the specified 
Host IP Address can manage the Router. Any other users will be 
rejected.
■Enable administration from a  whole subnet - This option allows a 
number of users within the specified  Host Network Address and 
Subnet Mask to administer the Router.
■Enable administration from  any Internet Host  - This option allows any 
host to access the administration pages.  
						

							
Advanced87
To remotely administer yo ur Router, enter 
http://xxx.xxx.xxx.xxx:8000  in the location bar of the browser 
running on the remote computer, where  xxx.xxx.xxx.xxx is the Internet IP 
address of the Router. You may then login using the administration 
password.
Your Internet IP address can be found  at the bottom of the screen. .
Syslog Select Syslog to display the syslog screen.
Check on the check box to enable  this feature, and then click Save. 
						

							
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Status and LogsSelecting Status and Logs  from the main menu displays the  Status,!
Logs
-and Routing Table in yur Web browser window. 
Status The Status  screen displays a tabular repres entation of your network and 
Internet connection. 
Status Screen  
						

							
Status and Logs89
LogsLogs will allow you to view both the normal events, and security threats 
logged by the Router.
Logs Screen
Select Incoming Log or Outgoing Log from the  Ty p e drop-down menu. 
The Incoming Log will display a temporary log of the Source IP Addresses 
and Destination Port Numbers fo rthe in coming Internet trafic. Click the 
Save Log button to save this information to !a file on your PC's hard drive. 
Click the Refresh button to update the log.  click the Clean button to clear 
all the information that is displayed.
The Outgoing Log will display a temporary log of the LAN IP Addresses, 
Destination URLs or IP Addresses, Destination URLs or IP Address, and 
Service or Port Numbers for the outg oing Internet traffic. Click the Save 
Log button to save this information to a file on your PC's hard drive. Click 
the Refresh button to  update the log. Click the Clearn button to clear all 
the information that is displayed. 
						

							
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Select the Routing table tab to  display routing information used by the 
Router. The information is displayed in  the form at shown as below.
Selecting Support/Feedback  from the main menu displays the  Support
and  Feedback  screens.
Support Support Screen
Selecting the  Support option on the main menu displays the support links 
screen, which contains a list of Inter net links that provide information and 
support concer ning the Router /Routing Table
Support/Feedback 
						

							
Status and Logs91
FeedbackFeedback Screen
Selecting the  Feedback option displays the Feedback screen and allows 
you to provide feedback to 3Com on the operation of your Router . This 
screen should not be used to obtain technical support. 
						

							
92CHAPTER 5: ROUTER CONFIGURATION 
						

							
6
TROUBLESHOOTING
Basic Connection 
Checks■Check that the Router is connected to your co mputers and to the 
cable/DSL modem, and that all the eq uipment is powered on. Check 
that the LAN Status and Cable/DSL Status LEDs on the Router are 
illuminated, and that any corr esponding LEDs on the cable/DSL 
modem and the NIC are also illuminated.
■Ensure that the computers have completed their start-up procedure 
and are ready for use. Some network interfaces may not be correctly 
initialized until the start-up procedure has completed.
■If the link status LED does not illuminate for a port that is connected, 
check that you do not have a faulty cable. Try a different cable.
Browsing to the 
Router
Configuration
ScreensIf you have connected your Router and computers together but cannot 
browse to the Router configuration screens, check the following:
■Confirm that the physical connection between  your computer and the 
Router is OK, and that the LAN Status LEDs on the Router and NIC are 
illuminated and indicating the same speed (10Mbps or 100Mbps). 
Some NICs do not have status LEDs, in which case a diagnostic 
program may be available that can  give you this information.
■Ensure that you have configured your computer as described in 
Chapter 3
,Setting Up Your Computers . Restart your computer while it 
is connected to the Router to ensur e that your computer receives an IP 
address.
■When entering the address of the Rout er into your web browser, 
ensure that you use the full URL  including the http:// prefix (e.g. 
http://192.168.1.1 ).
■Ensure that you do not have a Web proxy enabled on your computer. 
Go to the Control Panel  and click on Internet Options . Select the  
						

							
104CHAPTER 6: TROUBLESHOOTING
Connections  tab and click on the  LAN Settings button at the bottom. 
Make sure that the  Proxy Server option is unchecked.
■If you cannot browse to the Router, use the  winipcfg utility in 
Windows 95/98/ME to verify th at your computer has received the 
correct address information from the Router. From the  Start menu, 
choose Run and then enter  winipcfg. Check that the computer has 
an IP address of the form 192.168.1.xxx (where xxx is in the range 
2-254), the subnet mask is 255.255.255.0, and the default Router is 
192.168.1.1 (the address of the Router).  If these are not correct, use 
the Release  and Renew  functions to obtain a new IP address from the 
Router. Under Windows 2000, use the  ipconfig command-line utility 
to perform the same functions.
■If you still cannot browse to th e Router, then use the Discovery 
program on the accompanying CD-ROM as described in  Appendix A
.
Connecting to the 
InternetIf you can browse to the Router configuration screens but cannot access 
sites on the Internet, check the following:
■Confirm that the physical connection be tween the Router and the 
cable/DSL modem is OK, and that the link  status LEDs on both Router 
and modem are illuminated.
■Confirm that the connection between the modem and the cable/DSL 
interface is OK.
■Ensure that you have entered the  correct information into the Router 
configuration screens as required by your  Internet Service Provider. Use 
the “Internet Settings” screen to verify this.
■For DSL users, check that the PPPoE or  PPTP user name, password and 
service name are correct, if these are required. Only enter a PPPoE 
service name if your ISP requires one.
■For cable users, check whether your ISP requires a fixed MAC 
(Ethernet) address. If so, use the  Clone MAC Address feature in the 
Router to ensure that the correct MAC address is presented.
■For cable users, check whether your ISP requires a fixed  Host Name. If 
so, enter the required  Host Name in the Internet Settings  screen.
■Ensure that your computers are not configured to use a Web proxy. 
On Windows computers, this  can be found under Control Panel > 
Internet Options  > Connections .