1. Verify the network cable first.

- The cable length is 100 meters max.

- 10Mbps device can use Cat.3 and Cat.5 cable and 100Mbps device must use Cat.5 cable. Please use Cat.5 cable for all network connections to prevent wrong cables being used.

- Try another good cable.

2. Verify the connection port of the Hub.

- Try another port of the Hub.

< Case [ A ] >

- If straight-through cables (not crossover cables) are used, please use the MDI-X ports of Hub. The MDI (Uplink) port is for Hub-to-Hub connection.

- If the last MDI-X port (Port 8 of DuFastHUB-8As, Port 16 of DuFastHUB-16As) is used, do not use the MDI (Uplink) port at the same time because they share the same components of the hub.

- Because the MDI/MDI-X function of Port 24 of DuFastHUB-24As is switched by a push button, please switch that button to check if it is at the right function.

< Case [ B ] >

- Computer-to-Hub please use MDI-X ports. Hub-to-Hub/Switch connection can be done from the MDI (Uplink) port to the MDI-X port of another hub with straight-through cables.

- If the MDI (Uplink) port is used, do not use the last MDI-X port (Port 8 of DuFastHUB-8As, Port 16 of DuFastHUB-16As) at the same time because they share the same components of the hub.

3. Hub-to-Hub cascading

- If the connection between the hubs works at 10Mbps, it has the same limitation of 10Mbps hubs ¡V 4 units maximum allowed.

- If the connection between the hubs works at 100Mbps, it has the same limitation of 100Mbps hubs ¡V the Class II limitation.

Class II Limitation of 100Mbps Hub :

- Cascading 100Mbps Hubs together, maximum 2 units is allowed.

- The total cable length between any two network devices on the 100Mbps Hubs is 205 meters maximum, I.e. A+B+C < 205 meters.

4. Stack the Hubs

- DuFastHUB-8As/16As/24As can be stacked together to expand the connection capacity. If DuFastHUB-24As, 4 units are allowed to stack. If DuFastHUB-8As/16As, 6 units are allowed to stack.

5. Verify the function of the computer.

- Try the connection on another computer that is no problem.

- Verify the network adapter and network configuration of the computer.

6. Verify the Hub function.

- Check the power input of the hub by the Power LED. If fail, check the power input.

- Try another Hub.

[Notes:] You can diagnosis the network problem with the LED of the Hub.

1. Power : Indicates the power input of the Hub.

2. Link : Indicates a valid network connection. If the indicator is in green color, it is a 100Mbps connection. If the indicator is in yellow color, it is a 10Mbps connection.

3. Act : Indicates network traffic.

4. Col. : Indicates packets collision happen. Flashing of Col. Is the normal operation of Ethernet. But if the Col. Is flashing very busy, the loading of the network may be very heavy.

5. Partition : Indicates some error happening on that connection and that connection has been partitioned from the hub. That can prevent the problem to interfere other connections. If the problem disappears, the partition of that port will OFF.