S
PANNING
T
REE
A
LGORITHM
C
ONFIGURATION
3-127
therefore only forwarded between root ports and designated ports,
eliminating any possible network loops.
Once a stable network topology has been established, all bridges listen for
Hello BPDUs (Bridge Protocol Data Units) transmitted from the Root
Bridge. If a bridge does not get a Hello BPDU after a predefined interval
(Maximum Age), the bridge assumes that the link to the Root Bridge is
down. This bridge will then initiate negotiations with other bridges to
reconfigure the network to reestablish a valid network topology.
RSTP is designed as a general replacement for the slower, legacy STP.
RSTP achieves must faster reconfiguration (i.e., around one tenth of the
time required by STP) by reducing the number of state changes before
active ports start learning, predefining an alternate route that can be used
when a node or port fails, and retaining the forwarding database for ports
insensitive to changes in the tree structure when reconfiguration occurs.
Displaying Global Settings
You can display a summary of the current bridge STA information that
applies to the entire switch using the STA Information screen.
Field Attributes
•
Spanning Tree
State
– Shows if the switch is enabled to participate
in an STA-compliant network.
•
Bridge ID
– A unique identifier for this bridge, consisting of the
bridge priority and MAC address (where the address is taken from the
switch system).
x
Designated
Root
Designated
Port
Designated
Bridge
x
x
x
Root
Port
x
Summary of Contents for 8612XL3
Page 2: ......
Page 26: ...CONTENTS xxvi ...
Page 40: ...INTRODUCTION 1 14 ...
Page 69: ...BASIC CONFIGURATION 3 15 ...
Page 175: ...PORT CONFIGURATION 3 121 ...
Page 337: ...IP ROUTING 3 283 Web Click Routing Protocol RIP Statistics ...
Page 379: ...MULTICAST ROUTING 3 325 Command Usage ...
Page 396: ...CONFIGURING THE SWITCH 3 342 ...
Page 582: ...COMMAND LINE INTERFACE 4 186 ...
Page 806: ... 224 Command Mode Privileged Exec Example Console clear vrrp 1 interface 1 counters Console ...
Page 826: ... 6 ...
Page 828: ...TROUBLESHOOTING B 2 ...
Page 838: ...GLOSSARY Glossary 10 ...
Page 845: ......