Publication date:Aug., 2014
Revision A1
38
Now we apply VLAN technology to configure the system shown as the figure
above. We can partition the users into the different logical networks which have
their own broadcast domain. The traffic will not disturb among these logical
networks. The users 1x (x denotes a ~ d) are members of VLAN 1. Any traffic within
VLAN 1 does not flow to VLAN 2 and others. This helps us configure the network
easily according to the criteria needed, for example, financial, accounting, R&D and
whatever you think it necessary. You can also easily move a user to a different
location or join a new user somewhere in the building to VLAN. Without VLAN, it is
very hard to do. Basically, VLAN can afford offering at least 3 benefits: move and
change users, reduce broadcast traffic and increase performance, Security.
Besides, VLAN can highly reduce the traffic congestion and increase total
performance because there are no more too many users in the same broadcast
domain.
There are many types of VLAN applied. Most popular is port-based VLAN,
tag-based VLAN and protocol-based VLAN.
Port-based VLAN
Some physical ports are configured as members of a VLAN. All stations
attached on these ports can communicate with each other.
Tag-based VLAN
It identifies the membership by VLAN ID, no matter where the packet
comes from. It is also referred to as 802.1Q VLAN.
Protocol-based VLAN
Fig. 3-9