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5 Troubleshooting
5.1 Resolving Connection Problems
Possible causes a connection problem where the Link LED does not light up even though the cable is
connect are:
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The attached device is not powered on.
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The cable may not be the correct type or is defective.
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The cable installed in the building is defective.
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The connection has come loose on either end.
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The port is defective.
5.2 Q&A
Q1. Computer A can connect to Computer B, but cannot connect to Computer C through the switch.
A1. There are many possibilities for this issue, including:
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The network device on Computer C may be defective. Check the Link/Act status of the port
connected to Computer C on the switch. Try connecting Computer C to another port, and try
another connecting another device to this port to ensure the port is not defective.
•
The network configuration on Computer C may be incorrect. Verify that the network settings
(e.g. IP address, subnet mask) on Computer C are correct.
•
A software firewall on Computer C (e.g. ZoneAlarm, Windows Firewall, Norton Firewall) is
preventing access to the computer.
•
Computer A and Computer C are set up on separate VLANs on the switch and therefore cannot
communicate with each other.
Q2. User is unable to access the CLI through the console port.
A2. Check the following:
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The COM port default parameters are [Baud Rate: 57600, Data Bits: 8, Parity Bits: None, Stop
Bit: A, Flow Control: None]. Verify the COM port parameters in the terminal program.
•
Check the RS-232 cable is not damaged and is connected properly into the console port on the
switch and the serial port of the computer.
•
Check if the COM of the PC is enabled.
