Hardware Problems

Hardware Problems

Hardware problems can cause a network to be slow or inoperable. These problems are usually in the form of packet loss or corruption. Both of these problems can cause increased network traffic to the point of unmanageable congestion. Items to check at the physical level are:

Controller board: Even if the network media bandwidth is capable of handling the network traffic load, the individual station may not be able to handle the traffic. This is evidenced by a high degree of traffic on the network interface for no apparent reason. This traffic can be seen using the gr_osview tool (see the gr_osview(1) online reference page for options to see network traffic statistics). If traffic is unusually heavy on the interface, then there may be a problem with the controller, or the controller may be too slow to handle the volume of traffic. You may need a high-speed controller like the Efast card.
Transmitter and controller: Ensure that the Signal Quality Error (SQE), also called heartbeat, is disabled on both the transmitter and controller. SQE can cause unnecessary network traffic between the local station and the transceiver. See the installation guides for your network controller and transceiver for instructions on disabling SQE. By default, all Silicon Graphics network controller boards are shipped with SQE disabled.
Physical problems with the media: Cables, taps, and other hardware will periodically break or malfunction. A time domain reflectometer (TDR) is essential for troubleshooting Ethernet cable problems. A good analyzer is also strongly recommended to assist in isolating network physical problems. Silicon Graphics' NetVisualyzer product supplies a visual network analyzer ideal for locating physical problems with the media.