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CrossFire 8600/8605 Token-Ring Switches v. 1.2, P/N: 710001641 Switch Configuration
SNMP Configuration Menu
The next menu item in the Configuration m enu 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 acc ess from th e
Configuration menu.
Spanning Tree Protocol
The spanning tree protocol (STP) is a bridge-to-bridge link management protocol
that provides path redundancy while preventing unde sirable loops. To provi de path
redundancy, spanning tree protocol defines a tree that spans all switches and
bridges in the extended net work. If one of the net work segm ents in t he t ree becomes
inaccessible, STP reconfigures itself to reesta blish the links. To preve nt 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 selectio n of port priori ty/ 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 lowe r the path cost. Switche s an d b ridges in the networ k at te mpt
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 ha ve the sa me pa th cost, the STP devic e select s t he one wit h
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 val ue ass igned, the l owest port number wil l b e
selected.