Local Network vs. Remote Network:
Local Network: A local network, also referred to as a LAN (Local Area Network), is a network that covers a limited geographical area, typically within a building, office, or campus. Devices within a local network are usually connected to the same physical network infrastructure and can communicate with each other directly without the need for routing. Local networks are often assigned private IP addresses, and communication within the network occurs at the data link and network layers of the OSI model.
Remote Network: A remote network refers to a network that is separate and distinct from the local network. It can be located in a different geographical location or be part of a different organization. Communication between devices in a local network and devices in a remote network requires routing. Data packets are forwarded from the local network to the remote network through routers or Layer 3 switches that connect the networks together. Remote networks are often assigned public IP addresses, and communication across remote networks occurs at the network layer of the OSI model.
Understanding these basic routing concepts helps in designing and managing networks, determining network paths, and troubleshooting connectivity issues.
Basic switching concepts are essential for understanding how network switches operate and facilitate communication within a local area network (LAN). Here are explanations of some key concepts:
MAC Address Tables: A MAC address table, also known as a switching table or content-addressable memory (CAM) table, is a crucial component of network switches. It is a database that associates MAC (Media Access Control) addresses with the physical ports of the switch.
When a switch receives an Ethernet frame, it examines the source MAC address in the frame's header and updates its MAC address table accordingly. The switch records the MAC address and the port on which it received the frame. This process allows the switch to learn the MAC addresses and associate them with the appropriate ports. As a result, when the switch needs to forward traffic to a specific MAC address, it refers to its MAC address table to determine the appropriate outgoing port.
MAC Address Filtering: MAC address filtering, also known as MAC filtering, is a security feature available on some network switches. It allows administrators to control access to the switch based on MAC addresses.
By configuring MAC address filtering, administrators can specify a list of permitted MAC addresses. The switch then examines the source MAC address of incoming frames and compares them to the allowed MAC addresses. If the source MAC address matches an entry in the allowed list, the switch forwards the frame; otherwise, it discards it.
MAC address filtering can be used to enhance network security by only allowing authorized devices with specific MAC addresses to access the network through the switch. However, it's worth noting that MAC addresses can be spoofed, so MAC filtering alone may not provide comprehensive security.
VLAN (Virtual Local Area Network): A VLAN is a logical segmentation of a physical LAN into multiple virtual LANs. VLANs enable network administrators to divide a single switch or multiple interconnected switches into separate broadcast domains, which behave as if they were physically independent networks.
With VLANs, devices within the same VLAN can communicate with each other as if they were connected to the same physical network, regardless of their physical location. However, devices in different VLANs require routing to communicate.
VLANs offer several benefits, including enhanced security, improved network performance, and simplified network management. By isolating traffic within VLANs, network administrators can control access and limit the broadcast domain size, reducing unnecessary traffic and improving overall network efficiency.
Network switches support the configuration of VLANs, allowing administrators to assign specific switch ports to different VLANs and define VLAN membership based on port, MAC address, or other criteria.
Understanding these basic switching concepts is crucial for designing and managing LANs, optimizing network performance, and implementing network security measures.
