3Com Router WL-537 User Manual

							
Forgotten Password and Reset to Factory Defaults105
Forgotten Password 
and Reset to 
Factory DefaultsIf you can browse to the Router configuration screen but cannot log on 
because you do not know or have forgotten the password, follow the 
steps below to reset the Router to it’s factory default configuration. 
CAUTION: All your configuration changes will be lost, and you will need 
to run the configuration wizard again bef ore you can re-establish your 
Router connection to the Internet. Also, other computer users will lose 
their network connections whilst this process is taking place, so choose a 
time when this would be convenient.
1 Remove power from the Router.
2 Disconnect all your computers and the cable/DSL modem from the 
Router.
3 Using a straight through Ethernet cable, connect the Ethernet Cable/DSL 
port on the rear of the Router  to any one of the LAN ports.
4 Re-apply power to the Router. The Alert LED will flash as the Router starts 
up, and after approximately 30 seconds will start to flash more slowly 
(typically 2 seconds on, 2 seconds off). Once the Alert LED has started to 
flash slowly, remove power from the Router.
5 Remove the cable connect ing the Cable/DSL port to the LAN port, and 
reconnect one of your computers to one of the Router LAN ports.
6 Re-apply power to the Router , and when the start-up sequence has 
completed, browse to: 
http://192.168.1.1
and run the configuration wizard. You may need to restart your computer 
before you attempt this.
7 When the configuration wizard has  completed, you may reconnect your 
network as it was before.
Wireless 
Networking■Ensure that you have an 802.11b or 802.11g wireless adapter for 
each wireless computer, and that it is correctly installed and 
configured. Verify that each Wireless computer has either Windows 
95 or higher or MAC OS 8.5 or higher.
■Verify that your wireless computers are configured to work in 
Infrastructure mode and not Ad Hoc mode. The Router contains an 
Access Point that is designed to operate in Infrastructure mode. Ad 
Hoc mode is not supported by the Router. 
						

							
106CHAPTER 6: TROUBLESHOOTING
■If you have a wired and a wireless NIC in the same computer, ensure 
that the wired NIC is disabled.
■Check the status of the Router Wireless LED, it should be lit if wireless 
is enabled and will flash when there is wireless activity. If not lit go to 
“Wireless Settings”
 and enable wireless networking.
■Ensure that the TCP/IP settings for all devices are correct.
■Ensure that the Wireless Clients are using the same SSID or Service 
Area Name as the Router. The SSID is case-sensitive
■Ensure that the encryption method and level that you use on your 
clients are the same as those configured on the Router. The Router can 
simultaneously support WPA and WEP encryption, but can only 
support one configuration of each.
■Ensure that you have the Wire less computer enabled in the list of 
allowed MAC addresses if you are using  Wireless Connection control 
on the Router. 
■If you are having difficulty connecting or are operating at a low speed 
try changing the antenna positions on th e rear of the Router. For more 
effective coverage you can try reorientating your antennae. Place one 
antenna vertically  and one horizontally  to improve coverage. 
Additionally consider moving the wireless computer closer to the 
Router to confirm that the building stru cture or fittings are not 
adversely affecting the connectivity.  If this resolves the problem 
consider relocating the Wireless computer  or the Router, or trying a 
different channel on the Router.
■Sources of interference: The 2.4G hz ISM band is used for 802.11b and 
802.11g. This is generally a licence fr ee band for low power 
applications, and you may have other devices at your location that 
operate in this frequency band. You should take care to ensure that 
there are no devices like microwave ovens for example close to the 
Router or wireless computers as this could affect receiver sensitivity 
and reduce the performance of  your network. If you are unsure try 
relocating both the wireless compute rs and the Router to establish 
whether this problem exists.
■Most wireless computer Adapters will  scan the channels for the 
wireless Router. If a wireless comp uter has not located the Router then 
try initiating a search manually if the client software supports this 
feature or manually set the channel on your wireless computer to 
correspond to the Router channel nu mber. Please refer to your 
Wireless computer adapter documentation and vendor to do this. 
						

							
Power LED or Power Adapter OK LED Not Lit107
■Speed of connection: The 802.11b and 802.11g standards will 
automatically choose the best speed depending on the quality of your 
connection. As the signal quality weakens then the speed falls back to 
a lower speed. The speeds supported by 802.11g are 54 Mbps, 
48 Mbps, 36 Mbps, 24 Mbps, 18 Mbps, 12 Mbps, and 6 Mbps. The 
speeds supported by 802.11b are 11 Mbps, 5.5 Mbps, 2 Mbps and 
1 Mbps. In general the closer you are to the Router the better the 
speed. If you are not achieving the speed you had anticipated then try 
moving the antenna on the Router or  moving the Wireless computer 
closer to the Router. In an ideal network the Router should be located 
in the centre of the network with  Wireless computers distributed 
around it. Applications are  generally available with the computer 
wireless card to carry out a site survey. Use this application to find the 
optimal siting for your wire less computer. Consult your Computer 
Card documentation and vend or for more details.
Power LED or 
Power Adapter OK 
LED Not Lit■Check that your Router is receiving  power by looking at the status of 
the Power LED on the front panel and the Power Adapter OK LED on 
the rear panel:
■If both LEDs are lit green then the unit is receiving power.
■If both LEDs are unlit then no power is being supplied to the unit. 
Check that the power adapter is plugged into a working mains 
outlet and that the mains outlet is supplying power. If the mains 
socket is supplying power then the  power adapter or power 
adapter connection may be faulty. See  “
Replacement Power 
Adapters” below.
■If the Power Adapter OK LED is lit but th e Power LED is unlit then 
there may be a fault with your unit. Contact 3Com Technical 
Support.
■Check that you are using the correct  power adapter for your Router. 
You should only use the power adapter supplied with your Router.
Replacement Power Adapters If both the Power Adapter OK LED and Power LED are off, check your 
power adapter conn
ection. If the mains outlet is working and is capable 
of supplying power to other  devices, contact 3Com Technical Support 
and ask for a replacement power adapter. Please quote the power 
adapter part number shown on the OfficeConnect power adapter you are 
using. 
						

							
108CHAPTER 6: TROUBLESHOOTING
Alternatively, quote the part number for your region:
Power Adapter Part Numbers
Alert LEDThe Alert LED will flash when the Router unit is first powered up while 
the system software checks the hardware for proper operation. Once the 
Router has started normal operation , the Alert LED will go out.
■If the Alert LED does not go out following start up, but illuminates 
continuously, this indicates that the software has detected a possible 
fault with the hardware. Remove power from the Router, wait 10 
seconds and then re-apply power. If the Alert LED comes on 
continuously again, then a fault has been detected. Locate the copy of 
the Router software on the  accompanying CD-ROM or 3Com web site 
(
http://www.3com.com) and upload it to th e Router to see if this 
clears the fault (refer to “Recovering from Corrupted Software” 
below). If this does not fix the prob lem, contact your supplier for 
further advice.
■During normal operation,  you may notice the Alert LED lighting briefly 
from time to time. This indicates th at the Router has detected a hacker 
attack from the Internet and has prevented it from harming your 
network. You need take no specific action on this, unless you decide 
that these attacks are happening frequently in which case you may 
wish to discuss this with your ISP. The Router  logs such attacks, and 
this information is available through  the Status and Logs screens.
Recovering from 
Corrupted SoftwareIf the Alert LED remains permanently on following power-up, it is possible 
that the system software has become cor rupted. In this condition, the 
Part NumberRegion
3C16760US and Canada
3C16761UK
3C16762Europe and Middle East
3C16763Australasia (except Japan and Korea)
3C16764South Africa
3C16766Japan
3C16767Korea
3C16768Argentina 
						

							
Frequently Asked Questions109
Router will enter a “recovery” state; DHCP is disabled, and the LAN IP 
address is set to 192.168.1.1. Follow  the instructions below to upload a 
new copy of the system software  to a Router unit in this state.
Ensure that one of your computers has  a copy of the new software image 
file stored on its hard disk or available on CD-ROM.
The latest software is available on 3Com’s Web site at:
www.3com.com .
1Remove power from the Router and  disconnect the Cable/DSL modem 
and all your comp uters, except for the one computer with the software 
image.
2 You will need to reconfigure this computer with the following static IP 
address information:
■IP address: 192.168.1.2
■Subnet mask: 255.255.255.0
■Default Router address: 192.168.1.1
3 Restart the computer, and re-apply power to the Router.
4 Using the Web browser on the computer, enter the following URL in the 
location bar: 
http://192.168.1.1.
This will connect you to the Microcode Recovery utility in the Router.
5 Follow the on-screen instructions. Enter the path and filename of the 
software image file.
6 When the upload has completed, the Router will restart, run the self-test 
and, if successful, resume normal oper ation. The Alert LED will go out.
7 Refer to the Installation Guide to  reconnect your Router to the Cable/DSL 
modem and the computers in your network. Do not forget to reconfigure 
the computer you used for the software upload.
If the Router does not resume normal op eration following the upload, it 
may be faulty. Contact your supplier for advice.
Frequently Asked 
QuestionsHow do I reset the Router to Factory Defaults?
See  “
Forgotten Password and Reset to Factory Defaults”. 
						

							
110CHAPTER 6: TROUBLESHOOTING
How many computers on the LAN does the Router support?
A maximum of 253 computers on the LAN are supported.
How many wireless clients does the Cable/DSL Router support? A maximum of 128 wireless clients are supported.
There are only 4 LAN ports on the Router. How are additional 
computers connected? You can expand the number of connections available on your LAN 
by using hubs, switches and wire less access points connected to 
the Router. 3Com wireless access po ints and OfficeConnect hubs 
and switches provide a simple,  reliable means of expanding your 
network; contact your supplier fo r more information, or visit:
http://www.3com.com/
Does the Router support virtual private networks (VPNs)?
The Router supports VPN passthrough, which allows VPN clients on 
the LAN to communicate with VPN hosts on the Internet. It is also 
possible to set up VPN hosts on  your LAN that clients elsewhere on 
the Internet can connect to, but this is not a recommended 
configuration.
Where can I download software updates for the Router? Updates to the Router software ar e posted on the 3Com support 
web site, accessible by visiting:
http://www.3com.com
What other online resources are there?
The 3Com Knowledgebase at:
http://knowledgebase.3com.com
is a database of technical info rmation covering all 3Com products. 
It is updated daily with information from 3Com technical support 
services, and it is available 24 hours a day, 7 days a week. 
						

							
A
USING DISCOVERY
Running the 
Discovery
Application3Com provides a user friendly Discovery application for detecting the 
Router on the network.
Windows Installation (95/98/2000/Me/NT)
1Insert the Router CD-ROM  in the CD-ROM drive on your computer. A 
menu will appear; select  Router Discovery.
Discovery will find the Router even  if it is unconfigured or misconfigured.
Discovery Welcome Screen
2 When the  Welcome screen is displayed click on  Next and wait until the 
application discovers the Routers  connected to your LAN. 
						

							
112APPENDIX A: USING DISCOVERY
3Highlight the  Cable/DSL Router  by clicking on it, and press  Next.
4 Click on  Finish to launch a web browser an d display the login page for 
the Router.
Discovered Finish !Screen
Discovered Router Screen 
						

							
B
IP ADDRESSING
The Internet 
Protocol SuiteThe Internet protocol suite consists of a well-defined set of 
communications prot ocols and several standard application protocols. 
Transmission Control Protocol/Internet  Protocol (TCP/IP) is probably the 
most widely known and is a combination of  two of the protocols (IP and 
TCP) working together. TCP/IP is an internationally adopted and 
supported networking standard that provides connectivity between 
equipment from many vendors over  a wide variety of networking 
technologies.
Managing the 
Router over the 
NetworkTo manage a device over the network, the  Router must be correctly 
configured with the following IP information:
■An IP address
■A Subnet Mask
IP Addresses and Subnet Masks Each device on your network must have a unique IP address to operate 
correctly. An IP address identifies the 
address of the device to which data 
is being sent and the address of the destination network. IP addresses 
have the format n.n.n.x where n is a decimal number between 0 and 255 
and x is a number between 1 and 254 inclusive.
However, an IP Address alone is not  enough to make your device operate. 
In addition to the IP address, you need to set a subnet mask. All networks 
are divided into smaller sub-networ ks and a subnet mask is a number 
that enables a device to identify the  sub-network to which it is 
connected. 
						

							
114APPENDIX B: IP ADDRESSING
For your network to work correctly,  all devices on the network must have:
■The same sub-network address.
■The same subnet mask.
The only value that will be different is the specific host device number. 
This value must always be unique.
An example IP address is ‘192.168.100.8’.  However, the size of the 
network determines the structure of this  IP Address. In using the Router, 
you will probably only encounter tw o types of IP Address and subnet 
mask structures.
Ty p e  O n e
In a small network, the IP address of  ‘192.168.100.8’ is split into two 
parts:
■Part one (‘192.168.100’) identifies the network on which the device 
resides.
■Part two (‘.8’) identifies the device within the network.
This type of IP Address operates on a subnet mask of ‘255.255.255.0’.
See an example about how a network with three computers and a Router 
might be configured.
Ta b l e 4     IP Addressing and Subnet Masking
Ty p e  Tw o
In larger networks, where there ar e more devices, the IP address of 
‘192.168.100.8’ is, again, split into  two parts but is structured differently:
■Part one (‘192.168’) identifies the netwo rk on which the device 
resides.
■Part two (‘.100.8’) identifies the device within the network.
DeviceIP AddressSubnet Mask
PC 1192.168.100.8255.255.255.0
PC 2192.168.100.33255.255.255.0
PC 3192.168.100.188255.255.255.0
Router192.168.100.72255.255.255.0