Local area networks (LAN) are integral to the operation of many businesses today. The most common LANs use Ethernet, a data link layer protocol, and Internet Protocol (IP), a network layer protocol.
A LAN is comprised of many elements: printers, monitors, PCs, IP phones, servers, storage hardware, networking equipment, security software, network applications, enterprise applications, office productivity applications, and more. Devices on the network are linked physically by twisted pair copper, fiber or wireless access points.
Troubleshooting LANs is typically the job for the frontline network support staff - engineers and technicians. Common problems include user connection issues and slow networks.
Root causes of LAN problems are frequently caused by one of these three sources:
1. Physical layer: copper, fiber or wirelessPossible causes:
- Damaged or dirty cabling or terminations
- Excessive signal attenuation
- Insufficient cable bandwidth
- Wireless interference
2. Network Layer: Ethernet and IPPossible causes:
- Damaged networking devices
- Incorrect or sub-optimal device configurations
- Authentication and association issues
- Insufficient network bandwidth
3. Switches and VLANs Possible causes:
- Excessive utilization
- Too many errors
- Incorrectly assigned VLAN membersh