Olicom 8600, 8605 manual Snmp Configuration Menu, Spanning Tree Protocol

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SNMP Configuration Menu

The next menu item in the Configuration menu is SNMP Configuration... This item opens a menu that is explained in Chapter 8, “Monitoring the Network with SNMP”.

The next section describes the STP and the STP menus that you can access from the Configuration menu.

Spanning Tree Protocol

The spanning tree protocol (STP) is a bridge-to-bridge link management protocol that provides path redundancy while preventing undesirable loops. To provide path redundancy, spanning tree protocol defines a tree that spans all switches and bridges in the extended network. If one of the network segments in the tree becomes inaccessible, STP reconfigures itself to reestablish the links. To prevent loops, STP selects just one switch port as the designated path to the root, assigning it the Forwarding, or active state. It assigns all other ports the blocking, or standby, state. A port in the blocking state does not forward any transmitted frames in any direction.

➽Note: In the VLAN STP configuration menu, for the selection of port priority/port path cost, select only the ports which are part of the current VLAN. Do not configure ports in other VLANs.

The path cost indicates the relative speed of the segment: The higher the speed of the segment, the lower the path cost. Switches and bridges in the network attempt to determine the path to the route with the lowest path cost. IEEE 802.1D recommends that you assign path costs using the following formula:

Path cost = 1000 / LAN speed in Mbps

If two ports to the root have the same path cost, the STP device selects the one with the highest priority (lowest value), an arbitrary value that you assign. To block traffic on a particular segment, assign it low port priority (high value)

If more ports have the same priority value assigned, the lowest port number will be selected.

CrossFire 8600/8605 Token-Ring Switches v. 1.2, P/N: 710001641 Switch Configuration