Ring Topology

Although not as commonly used as it once was, you might find yourself troubleshooting a ring network. Most ring networks are logical rings, meaning that each computer is logically connected to each other. A physical ring topology is a rare find but a Fiber Distributed Data Interface (FDDI) is often configured in a physical ring topology. A logical ring topology uses a central connecting device as with a star network called a multistation access unit (MSAU). When troubleshooting either a logical or physical ring topology, consider the following:

  • A physical ring topology uses a single length of cable interconnecting all computers and forming a loop. If there is a break in the cable, all systems on the network will be unable to access the network.

  • The MSAU on a logical ring topology represents a single point of failure. If all devices are unable to access the network, it might be that the MSAU is faulty.

  • Verify that the cabling and connectors have the correct specifications.

  • All Network Interface Cards (NICs) on the ring network must operate at the same speed.

  • When connecting MSAUs in a ring network, ensure that the ring in and ring out configuration is properly set.

Figure 2 shows how a single cable break would affect other client systems on a physical ring network.

Figure 2 Identifying cable breaks in a physical ring network.