GE D7600 Series Switch User Manual

In traditional networks, traffic broadcasts to all network devices, whether they are the intended
recipients or not. However, VLANs can be set up to contain only those devices that need to
communicate with each other. As a result, VLANs considerably reduce
network congestion. In addition, VLANs prevent broadcast storms from causing a
network from crashing due to volumes of traffic.
Multimedia applications, such as interactive training, video monitoring, and video/data trans-
missions, require large amounts of bandwidth. These applications are also extremely sensitive
to variable delays, which are inevitable on a shared Ethernet network. By
defining a VLAN based on the IP multicast address for all defined members on the
VLAN, adequate bandwidth will be available for these applications, providing true
multimedia Ethernet.
Because VLANs are independent, only the devices within the same VLAN can
communicate with each other. If a device in one VLAN wants to communicate with
a device in another VLAN, the traffic must go through a router.
VLAN implementation allows:
- Up to 64 VLANs in one switch.
- VLANs across multiple switches by using explicit or implicit tagging and the
GARP/GVRP protocol defined in IEEE802.1p and 802.1Q.
- An end station’s network interface card belongs to multiple VLANs.
-A switch port to be associated with multiple VLANs.
VLAN implementation allows VLAN membership to be defined based on ports.
Physical port numbers organizes port-based VLANs. For example, switch ports
1,2,4 and 6 can be grouped on VLAN, while server ports 3,5,7 and 8 can be on another VLAN.
Broadcasts from servers within each group would only go to the members of its own VLAN.
This ensures that broadcast storms cannot cause a network to crash due to
volumes of traffic.
Port-based VLAN is defined using a static binding between a VLAN and its associated ports.
The switch’s forwarding decision is based on the destination MAC address and
its associated port ID. Therefore, to make valid forwarding and flooding decisions, the switch
learns the relationship of the MAC address to its related port…and thus to the VLAN…at runtime.
Manageable 8/9-Port Switch
User’s Manual 9