Page 148 - Computer_Science_F5

Configuring VLANs (iii) While VLANs can help control
VLANs are configured on network latency better than a wide area
switches. Each port on a switch can be network (WAN), they are generally Chapter Three: Advanced Computer Networks
assigned to a specific VLAN. VLAN less efficient in terms of latency
tagging (using the IEEE 802.1Q standard) control compared to a local area
FOR ONLINE READING ONLY
adds a VLAN identifier to Ethernet frames network (LAN).
to indicate the VLAN membership.
(e) Key Characteristics of switched

Benefits of VLANS LANs
The key benefits of implementing Switching mechanism
VLANs are as follows: (i) Layer 2 switching: Switches forward
(i) VLANs enable network Ethernet frames based on MAC
administrators to enhance security addresses. They maintain a MAC
for network communication. address table that maps each MAC
(ii) They simplify the process of address to the corresponding switch
expanding or relocating a network port. This allows them to deliver
or network devices. frames only to the intended recipient,
(iii) VLANs provide flexibility by reducing unnecessary traffic.
allowing administrators to configure (ii) Layer 3 switching: Advanced
them in a centralised environment, switches can also perform routing
even if the devices are located in functions, handle IP addresses, and
different geographical locations. enable inter-VLAN communication.
(iv) By reducing latency and network
traffic load, VLANs improve overall Reduced collisions
network performance. Unlike hubs that broadcast incoming

data to all ports, switches send data only
Disadvantages and limitations of
VLANS to the port where the destination device
is connected. This segmentation of the
(i) VLANs carry the risk of virus network into smaller collision domains
propagation, as a single infected reduces collisions and increases efficiency.
system can potentially spread a
virus throughout the entire logical Full-duplex communication
network. Switches support full-duplex
(ii) In very large networks, there may communication, allowing devices to
be equipment limitations, requiring send and receive data simultaneously,
the addition of routers to manage the effectively doubling the network’s
increased workload. bandwidth.

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Student’s Book Form Five

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