VLAN Arrangements: Characteristics, Exam 200-125 | Cisco

VLAN Arrangements: Characteristics

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Which three statements are typical characteristics of VLAN arrangements? (Choose three.)



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A. B. C. D. E. F.


VLANs (Virtual Local Area Networks) are used to logically partition a physical network into multiple virtual networks. VLANs have several characteristics, and three of them are as follows:

A. A new switch has no VLANs configured: When a new switch is powered on, it is considered to be in its default VLAN. The default VLAN is typically VLAN 1, and all ports on the switch are assigned to this VLAN. In other words, the switch is not configured with any additional VLANs when it is first turned on.

B. Connectivity between VLANs requires a Layer 3 device: VLANs are isolated from each other, which means that devices in one VLAN cannot communicate with devices in another VLAN unless a Layer 3 device (such as a router or layer 3 switch) is used to connect them. Layer 3 devices are responsible for forwarding packets between VLANs, and they do so by routing the packets based on their destination IP addresses.

C. VLANs typically decrease the number of collision domains: A collision domain is a portion of a network where devices compete for access to the network medium (such as Ethernet cables). VLANs can be used to decrease the number of devices in a collision domain, which can reduce the likelihood of collisions and improve network performance. By separating devices into different VLANs, the number of devices in each collision domain can be reduced.

D. Each VLAN uses a separate address space: Each VLAN is assigned a unique VLAN ID, which is used to identify the VLAN. Devices in different VLANs can have the same IP address, but they are still considered to be in different subnets. This is because each VLAN has its own broadcast domain and its own set of MAC addresses.

E. A switch maintains a separate bridging table for each VLAN: A bridging table (also known as a MAC address table) is used by switches to keep track of which devices are connected to which ports. Each VLAN has its own bridging table, which means that a switch must maintain a separate table for each VLAN that it supports. This ensures that devices in different VLANs are isolated from each other.

F. VLANs cannot span multiple switches: A VLAN is typically confined to a single switch, and devices in different VLANs cannot communicate with each other unless a Layer 3 device is used to connect them. However, it is possible to configure VLAN trunks, which allow VLAN traffic to be carried between switches. This allows devices in different VLANs to communicate with each other, but it requires additional configuration and is not considered to be a typical characteristic of VLAN arrangements.