3COM 3CR858-91 User Manual

4.17 Mb





Welcome to the world of networking with 3Com®. In the modern


business environment, communication and sharing information is crucial.


Computer networks have proved to be one of the fastest modes of


communication but, until recently, only large businesses could afford the


networking advantage.




The OfficeConnect Cable/DSL Router is designed to provide a

Cable/DSL Router

cost-effectivemeans of sharing a single broadband Internet connection


amongst several computers. The Router also includes an electronic


“firewall” that protects your network using Stateful Packet Inspection


(SPI) to detect intruders and prevent them from seeing your files or


damaging your computers. The Router can also prevent your users from


accessing Web sites which you find unsuitable. This completely equipped,


Cable/DSL Router also features Virtual Private Network (VPN) initiation


and termination, allowing encrypted links to other private networks.


The example in Figure 1 shows a network without a Router where only


one computer is connected to the Internet. This computer must always


be powered on for the other computers on the network to access the




Figure 1 Example Network Without a Router

When you use the Router in your network (Figure 2), it becomes your connection to the Internet. Connections can be made directly to the Router, or to an OfficeConnect Switch or Hub, expanding the number of computers you can have in your network.

Figure 2 Example Network Using a Cable/DSL Router

Router Advantages 13

Router Advantages The advantages of the Router include:

Shared Internet connection for wired computers. The Cable/DSL Router also provides shared internet connection

No need for a dedicated, “always on” computer serving as your Internet connection

Cross-platformoperation for compatibility with Windows, Unix and Macintosh computers

Easy-to-use,Web-basedsetup and configuration

Provides centralization of all network address settings (DHCP)

Acts as a Virtual server to enable remote access to Web, FTP, and other services on your network

Security - Firewall protection against Internet hacker attacks and encryption to protect network traffic

Package Contents The Router kit includes the following items:

One OfficeConnect Cable/DSL Router

One power adapter for use with the Router

Four rubber feet

One Ethernet cable

One CD-ROMcontaining the Router Discovery program and this User Guide

Installation Guide

One Support and Safety Information Sheet

One Warranty Flyer

If any of these items are missing or damaged, please contact your retailer.


Minimum System

and Component


Your Router requires that the computer(s) and components in your network be configured with at least the following:

A computer with an operating system that supports TCP/IP networking protocols (for example Windows 95/98/NT/Me/2000/XP, Unix, Mac OS 8.5 or higher).

An Ethernet 10Mbps or 10/100 Mbps NIC for each computer to be connected to the four-portswitch on your Router.

A cable or DSL broadband connection to the Internet, with a suitable modem. The modem must have an Ethernet port for connection to your Router.

A Web browser that supports JavaScript, such as Netscape 4.7 or higher, Internet Explorer 5.0 or higher, or Mozilla 1.2.1 or higher.

Front Panel

The front panel of the Router contains a series of indicator lights (LEDs)


that help describe the state of various networking and connection






Figure 3 Router - Front Panel







1Alert LED


Indicates a number of different conditions, as described below.

Off - The Router is operating normally.

Flashing quickly - Indicates one of the following conditions:

The Router has just been started up and is running a self-testroutine, or

The administrator has invoked the Reset to Factory Defaults command, or

The system software is in the process of being upgraded

Front Panel 15

In each of these cases, wait until the Router has completed the current operation and the alert LED is Off.

Flashing slowly - The Router has completed the Reset to Factory Defaultsprocess, and is waiting for you to reset the unit. To do this, remove power, wait 10 seconds and then re-apply power. The Router will then enter the start-up sequence and resume normal operation.

If you have used a cable to reset the unit to Factory Defaults, refer to

“Forgotten Password and Reset to Factory Defaults” on page 93.

On for 2 seconds, and then off - The Router has detected and prevented a hacker from attacking your network from the Internet.

Continuously on - A fault has been detected with your Router during thestart-upprocess. Refer toChapter 6 “Troubleshooting”.

2Power LED


Indicates that the Router is powered on.

3Four LAN Status LEDs

Green (100Mbps link) / yellow (10Mbps link)

If the LED is on, the link between the port and the next piece of network equipment is OK. If the LED is flashing, the link is OK and data is being transmitted or received. If the LED is off, nothing is connected, the connected device is switched off, or there is a problem with the connection (refer to Chapter 6 “Troubleshooting”). The port will automatically adjust to the correct speed and duplex.

4Cable/DSL Status LED

Green (100Mbps link) / yellow (10Mbps link)

If the LED is on, the link between the Router and the cable or DSL modem is OK. If the LED is flashing, the link is OK and data is being transmitted or received. If the LED is off, nothing is connected, the modem is switched off or there is a problem (refer to Chapter 6 “Troubleshooting”).


Rear Panel

The rear panel (Figure 4) of the Router contains four LAN ports, one


Ethernet Cabler/DSL port, and a power adapter socket.


Figure 4 Router - Rear Panel




5 8



5Power Adapter Socket

Only use the power adapter supplied with this Router. Do not use any other adapter.

6Ethernet Cable/DSL port

Use the supplied patch cable to connect the Router to the Ethernet port on your cable or DSL modem. The port will automatically adjust to the correct speed and duplex.

7Four 10/100 LAN ports

Using suitable RJ-45cable, you can connect your Router to a computer, or to any other piece of equipment that has an Ethernet connection (for example, a hub or a switch). The LAN ports are configured as MDIX, for connection to a computer with a straight throughRJ-45cable.

8Power Adapter OK LED


Indicates that the power adapter is supplying power to the Router. If the LED is off, there may be a problem with the power adapter or adapter cable.





This chapter will guide you through a basic installation of the Router,




“Positioning the Router”.


“Connecting the Router”.

Safety Information

WARNING: Please read the “Safety Information” section in Appendix D before you start.

VORSICHT: Bitte lesen Sie den Abschnitt “Wichtige Sicherheitshinweise” sorgfältig durch, bevor Sie das Gerät einschalten.

AVERTISSEMENT: Veuillez lire attentivement la section“Consignes importantes de sécurité” avant de mettre en route.

Positioning the


You should place the Router in a location that:

is conveniently located for connection to the telephone socket.

allows convenient connection to the computers that will be connected to the four LAN ports on the rear panel, if desired.

allows easy viewing of the front panel LED indicator lights, and access to the rear panel connectors, if necessary.

When positioning your Router, ensure:

It is out of direct sunlight and away from sources of heat.

Cabling is away from power lines, fluorescent lighting fixtures, and sources of electrical noise such as radios, transmitters and broadband amplifiers.


Water or moisture cannot enter the case of the unit.

Air flow around the unit and through the vents in the side of the case is not restricted. 3Com recommends you provide a minimum of

25 mm (1 in.) clearance.

Using the Rubber Use the fourself-adhesiverubber feet to prevent your Router fromFeet moving around on your desk or when stacking with flat top units. Only

stick the feet to the marked areas at each corner of the underside of your Router.

Wall Mounting

There are two slots on the underside of the Router that can be used for


wall mounting.


When wall mounting the unit, ensure that it is within reach of the power




You will need two suitable screws to wall mount the unit. To do this:

1Ensure that the wall you use is smooth, flat, dry and sturdy and make two screw holes which are 150 mm (5.9 in.) apart.

2Fix the screws into the wall, leaving their heads 3 mm (0.12 in.) clear of the wall surface.

3Remove any connections to the unit and locate it over the screw heads. When in line, gently push the unit on to the wall and move it downwards to secure.

When making connections, be careful not to push the unit up and off the wall.

CAUTION: Only wall mount single units, do not wall mount stacked units.

Connecting the

To power up your Router, and then connect it to your modem and to a


computer, do the following:

1Plug the power adapter into the power adapter socket located on the back panel of the Router.

2Plug the power adapter into a standard electrical wall socket. Wait for the Alert LED to stop flashing.

Connecting the Router


3Ensure that your modem and computer are both switched on.

4Use the supplied cable to connect the Router’s Ethernet Cable/DSL port to the modem. Check that the Cable/DSL Status LED lights.

5Connect your computer to one of the 10/100 LAN ports on the Router. Check that the LAN Status LED for the port lights green.

See Figure 5 for an example configuration.

Figure 5 Connecting the Router

Your existing

Cable/DSL Internet



Connect Cable/DSL







Cable/DSL Router