Allied Telesis X600-48TS/XP, x600-48Ts, x600-24Ts/XP, X600-24TS Twisted Pair Port Link LED is Off

x600 Layer 3 Gigabit Ethernet Switch Installation Guide

Twisted Pair Port Link LED is Off

When a twisted pair port on the switch is connected to a properly operating end node, the Link LED for the port should be on. If a Link LED is off, do the following:

Note

A 1000Base-T connection can take from five to ten seconds to establish a link.

ˆVerify that the end node connected to the port is powered ON and is operating properly.

ˆCheck that the twisted pair cable is securely connected to the port on the switch and to the port on the end node.

ˆMake sure that the twisted pair cable does not exceed 100m (328 ft).

ˆVerify that you are using the appropriate category of twisted pair cable. For information, refer to Table 12 on page 80.

ˆDetermine if a crossover cable is required. Since the twisted pair ports feature auto MDI/MDI-X, you should be able to use a straight-through cable regardless of the type of device you connect to a port. However, if you disable Auto-Negotiation on a port and set a port’s speed and duplex mode manually, the port defaults to MDI-X. Disabling Auto- Negotiation may require manually configuring a port’s MDI/MDI-X setting or using a crossover cable.

ˆMake sure that the operating parameters of a port on the switch are compatible with the end node to which the port is connected. This may require using the switch’s operating system software.

ˆFor a switch port to successfully Auto-Negotiate its duplex mode with an end node, the end node should also be using Auto-Negotiation. Otherwise, a duplex mode mismatch can occur. A switch port using Auto-Negotiation defaults to half-duplex if it detects that the end node is not using Auto-Negotiation. This can result in a mismatch if the end node is operating at a fixed duplex mode of full-duplex.

To avoid this problem, disable Auto-Negotiation on a switch port and set the port’s speed and duplex mode manually if the end node has a fixed duplex mode of full-duplex.

ˆThe switch has a bad cable detection feature that enables it to determine if a twisted pair cable has a electrical short that might cause a network loop. If the switch detects a bad cable on a port, it does not establish a link on that port. In this situation, replace the cable.

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