SNR S2989G-24TX-POE — настройка и устранение неполадок в сетевых коммутаторах [75/553]

Превью страниц Страница 75 / 553

2-11

S2989G-24TX Operation Manual Chapter 2 Layer 2 services

Configuration

Switch(Config-Mstp-Region)#

2.3.4

Port Loopback Detection Troubleshooting

The function of port loopback detection is disabled by default and should only be

enabled if required.

2.4

ULDP

2.4.1

Introduction to ULDP Function

Unidirectional link is a common error state of link in networks, especially in fiber links.

Unidirectional link means that only one port of the link can receive messages from the

other port, while the latter one can not receive messages from the former one. Since the

physical layer of the link is connected and works normal, via the checking mechanism of

the physical layer, communication problems between the devices can not be found. As

shown in Graph, the problem in fiber connection can not be found through mechanisms in

physical layer like automatic negotiation.

Switch A

Switch B

Figure 2-4 Fiber Cross Connection

g1/0/1

g1/0/2

g1/0/3

g1/0/4