User Guide
Table Of Contents
- Cisco Wireless ISR and HWIC Access Point Configuration Guide
- Contents
- Preface
- Overview
- Configuring Radio Settings
- Enabling the Radio Interface
- Roles in Radio Network
- Configuring Network or Fallback Role
- Universal Client Mode
- Configuring Universal Client Mode
- Configuring Radio Data Rates
- Configuring Radio Transmit Power
- Configuring Radio Channel Settings
- Enabling and Disabling World Mode
- Enabling and Disabling Short Radio Preambles
- Configuring Transmit and Receive Antennas
- Disabling and Enabling Access Point Extensions
- Configuring the Ethernet Encapsulation Transformation Method
- Enabling and Disabling Reliable Multicast to Workgroup Bridges
- Enabling and Disabling Public Secure Packet Forwarding
- Configuring Beacon Period and DTIM
- Configuring RTS Threshold and Retries
- Configuring Maximum Data Retries
- Configuring Fragmentation Threshold
- Enabling Short Slot Time for 802.11g Radios
- Performing a Carrier Busy Test
- Configuring Multiple SSIDs
- Configuring an Access Point as a Local Authenticator
- Understand Local Authentication
- Configure a Local Authenticator
- Guidelines for Local Authenticators
- Configuration Overview
- Configuring the Local Authenticator Access Point
- Configuring Other Access Points to Use the Local Authenticator
- Configuring EAP-FAST Settings
- Limiting the Local Authenticator to One Authentication Type
- Unblocking Locked Usernames
- Viewing Local Authenticator Statistics
- Using Debug Messages
- Configuring Encryption Types
- Configuring Authentication Types
- Configuring RADIUS Servers
- Configuring and Enabling RADIUS
- Understanding RADIUS
- RADIUS Operation
- Configuring RADIUS
- Default RADIUS Configuration
- Identifying the RADIUS Server Host
- Configuring RADIUS Login Authentication
- Defining AAA Server Groups
- Configuring RADIUS Authorization for User Privileged Access and Network Services
- Starting RADIUS Accounting
- Selecting the CSID Format
- Configuring Settings for All RADIUS Servers
- Configuring the Access Point to Use Vendor-Specific RADIUS Attributes
- Configuring the Access Point for Vendor-Proprietary RADIUS Server Communication
- Configuring WISPr RADIUS Attributes
- Displaying the RADIUS Configuration
- RADIUS Attributes Sent by the Access Point
- Configuring and Enabling RADIUS
- Configuring VLANs
- Configuring QoS
- Channel Settings
- Protocol Filters
- Supported MIBs
- Error and Event Messages
- Glossary
- Index
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Chapter 8 Configuring VLANs
Understanding VLANs
Understanding VLANs
A VLAN is a switched network that is logically segmented, by functions, project teams, or applications
rather than on a physical or geographical basis. For example, all workstations and servers used by a
particular workgroup team can be connected to the same VLAN, regardless of their physical connections
to the network or the fact that they might be intermingled with other teams. You use VLANs to
reconfigure the network through software rather than physically unplugging and moving devices or
wires.
A VLAN can be thought of as a broadcast domain that exists within a defined set of switches. A VLAN
consists of a number of end systems, either hosts or network equipment (such as bridges and routers),
connected by a single bridging domain. The bridging domain is supported on various pieces of network
equipment such as LAN switches that operate bridging protocols between them with a separate group
for each VLAN.
VLANs provide the segmentation services traditionally provided by routers in LAN configurations.
VLANs address scalability, security, and network management. You should consider several key issues
when designing and building switched LAN networks:
• LAN segmentation
• Security
• Broadcast control
• Performance
• Network management
• Communication between VLANs
You ex te nd V LA Ns i nto a w ir el es s L AN by add in g IE EE 80 2. 11 Q ta g awar en es s to t he a c ces s po int .
Frames destined for different VLANs are transmitted by the access point wirelessly on different SSIDs
with different WEP keys. Only the clients associated with that VLAN receive those packets. Conversely,
packets coming from a client associated with a certain VLAN are 802.11Q tagged before they are
forwarded onto the wired network.
Figure 8-1 shows the difference between traditional physical LAN segmentation and logical VLAN
segmentation with wireless devices connected.