Cabletron Systems CSX1000, CSX1200 manual Known Connect List Configuration Elements

USER’S GUIDE

KNOWN CONNECT LIST CONFIGURATION ELEMENTS

DEVICE NAME

The name of a bridge device that has been preconfigured in the On-node Device Database section of the Configuring Device Level Databases chapter. This is a device to which you want the system to connect and forward bridged unicast packets.

KNOWN CONNECT LIST BACKGROUND INFORMATION

In Unrestricted Mode, standard bridge processing attempts to forward frames with unknown or broadcast MAC addresses through all available interfaces. This can cause a problem with the limited bandwidth and high cost of dial-up WAN links. The CyberSWITCH’s Known Connect List feature, and its support of bridge filters, gives you flexible options in controlling the risk of bridge flooding over WAN links.

When operating as a bridge or in IP Host Mode, in the course of processing the MAC frames, the CyberSWITCH builds its bridge table and associates each MAC address it sees with an interface. When a remote bridge establishes a connection and begins sending traffic to the CyberSWITCH, the CyberSWITCH adds these remote addresses to its bridge table and associates the remote bridge with them. Later, if the connection is dropped, and if the CyberSWITCH receives a packet destined for one of the remote addresses, it will re-establish the connection with the remote bridge only if the remote bridge is specified on the Known Connect List, or if a forwarding filter is configured. Furthermore, if the Known Connect List option is used, the CyberSWITCH can only re-establish the connection while the remote bridge is still “known”; that is, if the system receives the new, outbound packet before the Spanning Tree Bridge Age Time timer ages-out the destination MAC address from the bridge table. If a connect filter is used, the CyberSWITCH can re-establish the connection regardless of how long it’s been since the last connection. The default Bridge Age Time is 5 minutes. Refer to page 220 to change the default value.

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