Implementing Ethernet Virtual LANs

Question 1

Broadcast domain

Answer 1

The set of all LAN-connected devices, so that when any of the devices sends a broadcast frame, all the other devices get a copy of the frame

Question 2

Virtual LANs (VLANs)

Answer 2

Individual broadcast domains cretaed by the switch, treating the ports in each domain as being completely separate

Question 3

Most common reasons for VLANs

Answer 3

• To reduce CPU overhead on each device
• To reduce security risks
• To create more flexible designs t
• To solve problems more quickly
• To reduce the workload for the Spanning Tree Protocol

Question 4

VLAN trunking

Answer 4

The process by which VLANs are forwarded to multiple interconneted switches

Question 5

VLAN tagging

Answer 5

The sending switch adds another header to the frame before sending it over the trunk. This extra trunking header includes a VLAN identifier (VLAN ID) field so that the sending switch can associate the frame with a particular VLAN ID, and the receiving switch can then know in what VLAN each frame belongs

Question 6

VLANs ranges

Answer 6

1-1005 Normal range
1006-4094 Extended range
0/4095 Reserved

Question 7

Native VLAN

Answer 7

Special VLAN ID (default VLAN 1) which frames with no 802.1Q header are part of
It must be agreed on if the switches support tagging

Question 8

VLAN Trunking Protocol (VTP)

Answer 8

VTP is a Cisco proprietary tool on Cisco switches that advertises each VLAN configured in one switch (with the vlan number command) so that all the other switches in the campus learn about that VLAN

Question 9

Dynamic Trunking Protocol (DTP)

Answer 9

Used to negotiate which trunking type to use between IEEE 802.1Q and ISL