HP ProCurve 520wl Wireless Access Point - Manual (Page 53)

VLAN Support
4-4
vlan support vlan support vlan support vlan support
Virtual Local Area Networks (VLANs) are logical groupings of network resources. Defined by software settings, VLAN
resources appear (to clients) to be in the same room, no matter where they are attached on the physical LAN segment. They
simplify traffic flow between clients and their frequently-used or restricted resources.
VLANs now extend as far as the access point signal reaches; clients can connect from anywhere in the broadcast area. The
broadcast area is defined by the network name configured for the wireless card on the access point device.
WL520 devices are fully VLAN-ready; however, by default VLAN support is disabled. Before enabling VLAN support, certain
network settings should be configured, and network resources such as a VLAN-aware switch, a RADIUS server, and possibly a
DHCP server should be available.
Once enabled, VLANs are used to more conveniently, efficiently, and easily manage your network.
Q
Manage adds, moves, and changes from a single point of contact
Q
Define and monitor groups
Q
Reduce broadcast and multicast traffic to unnecessary destinations
–
Improve network performance and reduce latency
Q
Increase security
–
Secure network restricts members to resources on their own workgroup
– Clients roam without compromising security
typical vlan configurations typical vlan configurations typical vlan configurations typical vlan configurations
VLANs collect and distribute data through wireless WL520 network interface cards (NIC). An Ethernet port on the access point
typically connects a wireless cell to a wired backbone. They communicate across a VLAN-capable switch that reviews packet
headers and directs traffic to the appropriate ports. On the wired network, a RADIUS server authenticates traffic and a DHCP
server manages IP addresses. Resources like servers and printers may be present, and a hub may include multiple APs,
extending the network over a larger area.
Figure 4-3 Figure 4-3 Figure 4-3 Figure 4-3 Components of a typical VLAN Components of a typical VLAN Components of a typical VLAN Components of a typical VLAN
vlan workgroups and traffic management vlan workgroups and traffic management vlan workgroups and traffic management vlan workgroups and traffic management
Traditional, dual-slot access point devices that are not VLAN-capable typically transmit broadcast and multicast traffic to all
wireless Network Interface Cards (NICs). This process wastes wireless bandwidth and degrades throughput performance. In
comparison, the dual-slot, VLAN-capable WL520 device is designed to efficiently manage delivery of broadcast, multicast,
and unicast traffic to wireless clients.
The WL520 device assigns clients to one of two VLANs designated by a network name. First, each one of the wireless NICs in
the WL520 device is configured with a unique network name and an 802.1Q-compliant VLAN identifier. Each NIC represents
a VLAN.
In this figure, the numbered items correspond to the
following components:
1. VLAN-enabled access point
2. VLAN-aware switch (IEEE 802.1Q
uplink)
3. WL520 management via wired host
(SNMP, Web interface or CLI)
4. DHCP Server
5. RADIUS Server
6. VLAN 1 (Wireless Card A)
7. VLAN 2 (Wireless Card B)