Issues that commonly cause network problems at the physical layer of a network

      

Issues that commonly cause network problems at the physical layer of a network

  

Answers


Faith
• Power-related - Power-related issues are the most fundamental reason for network failure. Also, check the operation of the fans, and ensure that the chassis intake and exhaust vents are clear. If other nearby units have also powered down, suspect a power failure at the main power supply.
• Hardware faults - Faulty network interface cards (NICs) can be the cause of network transmission errors due to late collisions, short frames, and jabber. Jabber is often defined as the condition in which a network device continually transmits random, meaningless data onto the network. Other likely causes of jabber are faulty or corrupt NIC driver files, bad cabling, or grounding problems.
• Cabling faults - Many problems can be corrected by simply reseating cables that have become partially disconnected. When performing a physical inspection, look for damaged cables, improper cable types, and poorly crimped RJ-45s. Suspect cables should be tested or exchanged with a known functioning cable.
• Attenuation - Attenuation can be caused if a cable length exceeds the design limit for the media, or when there is a poor connection resulting from a loose cable or dirty or oxidized contacts. If attenuation is severe, the receiving device cannot always successfully distinguish the component bits of the stream from each other.
• Noise - Local electromagnetic interference (EMI) is commonly known as noise. Noise can be generated by many sources, such as FM radio stations, police radio, building security, and avionics for automated landing, crosstalk (noise induced by other cables in the same pathway or adjacent cables), nearby electric cables, devices with large electric motors, or anything that includes a transmitter more powerful than a cell phone.
• Interface configuration errors - Many things can be misconfigured on an interface to cause it to go down, such as incorrect clock rate, incorrect clock source, and interface not being turned on. This causes a loss of connectivity with attached network segments.
• Exceeding design limits - A component may be operating suboptimally at the physical layer because it is being utilized at a higher average rate than it is configured to operate. When troubleshooting this type of problem, it becomes evident that resources for the device are operating at or near the maximum capacity and there is an increase in the number of interface errors.
• CPU overload - Symptoms include processes with high CPU utilization percentages, input queue drops, slow performance, router services such as Telnet and ping are slow or fail to respond, or there are no routing updates. One of the causes of CPU overload in a router is high traffic. If some interfaces are regularly overloaded with traffic, consider redesigning the traffic flow in the network or upgrading the hardware

Titany answered the question on November 30, 2021 at 12:53


Next: Common symptoms of network problems at the physical layer
Previous: Outline four parts of an email address

View More Data Communication and Networking Questions and Answers | Return to Questions Index


Exams With Marking Schemes

Related Questions