User Manual

Advanced Configuration
57
Bridge
The AP-600 is a bridge between your wired and wireless networking devices. As a bridge, the functions performed by
the AP-600 include:
• MAC address learning
• Forward and filtering decision making
• Spanning Tree protocol used for loop avoidance
Once the AP-600 is connected to your network, it learns which devices are connected to it and records their MAC
addresses in the Learn Table. The table can hold up to 10,000 entries. To view the Learn Table, click on the Monitor
button in the web interface and select the Learn Table tab.
The Bridge tab has four sub-categories.
– Spanning Tree
– Storm Threshold
– Intra BSS
– Packet Forwarding
Spanning Tree
A Spanning Tree is used to avoid redundant communication loops in networks with multiple bridging devices. Bridges
do not have any inherent mechanism to avoid loops, because having redundant systems is a necessity in certain
networks. However, redundant systems can cause Broadcast Storms, multiple frame copies, and MAC address table
instability problems.
Complex network structures can create multiple loops within a network. The Spanning Tree configuration blocks
certain ports on AP-600 devices to control the path of communication within the network, avoiding loops and following
a spanning tree structure.
For more information on Spanning Tree protocol, please see Section 8.0 of the IEEE 802.1d standard. The Spanning
Tree configuration options are advanced settings. Proxim recommends that you leave these parameters at their
default values unless you are familiar with the Spanning Tree protocol.
Storm Threshold
Storm Threshold is an advanced Bridge setup option that you can use to protect the network against data overload by:
• Specifying a maximum number of frames per second as received from a single network device (identified by its
MAC address).
• Specifying an absolute maximum number of messages per port.
The Storm Threshold parameters allow you to specify a set of thresholds for each port of the AP-600, identifying
separate values for the number of broadcast messages/second and Multicast messages/second.
When the number of frames for a port or identified station exceeds the maximum value per second, the AP-600 will
ignore all subsequent messages issued by the particular network device, or ignore all messages of that type.
– Address Threshold: Enter the maximum allowed number of packets per second.
– Ethernet Threshold:
Enter the maximum allowed number of packets per second.
– Wireless Threshold: Enter the maximum allowed number of packets per second.
Intra BSS
The wireless clients (or subscribers ) that associate with a certain AP-600 form the Basic Service Set (BSS) of a
network infrastructure. By default, wireless subscribers in the same BSS can communicate with each other. However,
some administrators (such as wireless public spaces) may wish to block traffic between wireless subscribers that are
associated with the same AP-600 to prevent unauthorized communication and to conserve bandwidth. This feature
enables you to prevent wireless subscribers within a BSS from exchanging traffic.
Although this feature is generally enabled in public access environments, Enterprise LAN administrators use it to
conserve wireless bandwidth by limiting communication between wireless clients. For example, this feature prevents
peer-to-peer file sharing or gaming over the wireless network.
To block Intra BSS traffic, set Intra BSS Traffic Operation to Block.
To allow Intra BSS traffic, set Intra BSS Traffic Operation to Passthru.