Network Design
Single Points of Failure
A single point of failure is any one device, cable or connection that, if it should fail or be removed from the network, would disable all or a sizable part of the network.
Most Cabletron Systems hardware seeks to eliminate single points of failure from within the device, by providing for redundant links or the distribution of essential functions among several related devices. Using devices in accordance with their
An example of a very obvious single point of failure is a shared segment of thick coaxial cable in an Ethernet network. All of the stations rely on the availability of the one coaxial segment. Should the segment fail, due to a break in the cable or the removal of a terminator, the network fails. A design eliminating the cable as a single point of failure might use several thin coaxial cable segments attaching to a repeater or modular chassis. Any one coaxial cable segment may fail without bringing down the other coaxial cable segments. The repeater can be seen as a single point of failure, but only from the point of view of the connection between segments, as the segments themselves will continue to operate without the repeater.
The location and elimination of single points of failure is a very difficult step in network planning. It is important to set realistic limits on the elimination of these single points of failure. A network that completely eliminates single points of failure will be more expensive and complex than a network that eliminates only the most dangerous single points of failure.
Redundancy
Redundancy is the provision of or availability of backup systems. Redundancy is designed into a
When designing a network, check the descriptions of the products to see if they support the creation of redundant links to devices. It is often a good idea to have some form of
Creating a Manageable Plan |
