Cabletron Systems CSX200 User Manual

Also see for SPECTRUM: User guide User guide User guide User guide Guide

Contents

CSX Bridge View3-20The Filtering Database WindowIn Figure 3-8, Filter Number 3 shows the Destination Ports as B54180E0, whichrepresents ports 1, 3, 4, 6, 8, 10, 16, 17, 25, 26, 27. Here’s how to translate the hexstring to port numbers:1. Translate each hex integer into a four-digit binary value:B 5 4 1 8 0 E 01011 0101 0100 0001 1000 0000 1110 0000Each “1” in the binary bitmask represents a Destination Port number:B 5 4 1 8 0 E 01011 0101 0100 0001 1000 0000 1110 00001,X,3,4 X,6,X,8 X,10,X,X X,X,X,1617,X,X,X X,X,X,X, 25,26,27,X X,X,X,XDeleting Special Database FiltersTo delete an enabled Special Database filter:1. In the Special Filters IO Table, select a filter to delete by clicking mousebutton 1 on the table entry.2. Click mouse button 1 on the Delete button at the bottom of the window.The Filtering Database WindowIn Transparent bridging, each bridge port uses the device’s Filtering Database todetermine a packet’s route through the bridge. The Filtering Database is createdfrom permanent entries made via management, and from entries learned as thebridge collects and stores the source address and port association from eachpacket it receives.When in the Forwarding state, the bridge examines each received packet andcompares the destination address to the contents of the Filtering Database. If thedestination address is located on the network from which the packet wasreceived, the bridge filters (does not forward) the packet. If the destinationaddress is located on a different network, the bridge forwards the packet to theappropriate network. If the destination address isn’t found in the FilteringDatabase, the bridge forwards the packet to all networks. To keep FilteringDatabase entries current, older entries are purged after a period of time, which iscalled the Dynamic Aging Time.The Filtering Database has two types of entries: Forwarding and Static. TheForwarding view of the Filtering Database contain addresses that the bridgeNOTEDeleting a filter doesn’t “delete” the filter; it just clears all the entries you made for thatinstance of the filter. In the example shown above, if you deleted the last entry in the list(Filter Number 19, Receive Port 4, Destination Port 1) any other entries for Filter 19would remain intact.