Cabletron Systems Cabletron CyberSWITCH CSX5500 User Manual

Also see for CyberSWITCH 5500: Quick start Manual

Contents

USER’S GUIDE286 CyberSWITCHKNOWN CONNECT LIST CONFIGURATION ELEMENTSD EVICE N AMEThe name of a bridge device that has been preconfigured in the On-node Device Database section ofthe Configuring Device Level Databases chapter. This is a device to which you want the system toconnect and forward bridged unicast packets.KNOWN CONNECT LIST BACKGROUND INFORMATIONIn Unrestricted Mode, standard bridge processing attempts to forward frames with unknown orbroadcast MAC addresses through all available interfaces. This can cause a problem with thelimited bandwidth and high cost of dial-up WAN links. The CyberSWITCH’s Known Connect Listfeature, and its support of bridge filters, gives you flexible options in controlling the risk of bridgeflooding over WAN links.When operating as a bridge or in IP Host Mode, in the course of processing the MAC frames, theCyberSWITCH 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 bridgewith them. Later, if the connection is dropped, and if the CyberSWITCH receives a packet destinedfor one of the remote addresses, it will re-establish the connection with the remote bridge only if theremote 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 theconnection 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 MACaddress from the bridge table. If a connect filter is used, the CyberSWITCH can re-establish theconnection regardless of how long it’s been since the last connection. The default Bridge Age Timeis 5 minutes. Refer to page 266 to change the default value.