13–6
MULTILINK ML810 MANAGED EDGE SWITCH – INSTRUCTION MANUAL
CONFIGURING RSTP THROUGH THE COMMAND LINE INTERFACE
CHAPTER 13: RAPID SPANNING TREE PROTOCOL
•
Root Port
: Indicates the port number, which is elected as the root port of the switch. A
root port of "0" indicates STP is disabled.
•
Root Path Cost
: A path cost is assigned to individual ports for the switch to determine
which ports are the forwarding points. A higher cost means more loops; a lower cost
means fewer loops. More loops equal more traffic and a tree which takes a long time
to converge, resulting in a slower system.
•
Designated Root
: Shows the MAC address of the bridge in the network elected or
designated as the root bridge.
•
Designated Root Priority
: Shows the designated root bridge's priority. The default
value is 0.
•
Root Bridge Forward Delay
: Indicates the designated root bridge's forward delay.
This is the time the switch waits before it switches from the listening to the forwarding
state. This value can be set between 4 to 30 seconds, with a default of 15.
•
Root Bridge Hello Time
: Indicates the designated root bridge's hello time. Hello
information is sent out every 2 seconds.
•
Root Bridge Max Age
: Indicates the designated root bridge's maximum age, after
which it discards the information as being old and receives new updates.
•
Topology Change Count
: Since the last reboot, the number of times the topology has
changed. Use this in conjunction with "show uptime" to find the frequency of the
topology changes.
•
Time Since topology Change
: The number of seconds since the last topology change.
The variables listed by the
show stp ports
command are:
•
Port#
: Indicates the port number. The value ranges from 1 to the maximum number of
ports in the switch.
•
Type
: Indicates the type of port. TP indicates twisted pair.
•
Priority
: STP uses this to determine which ports are used for forwarding. Lower
numbers indicate higher priority. The values range from 0 to 255, with a default of 128.
•
Path Cost
: This is the assigned port cost value used for the switch to determine the
forwarding points. Values range from 1 to 2000000. Lower values indicate a lower
cost and hence the preferred route. The costs for different Ethernet speeds are
indicated below. The Path cost in STP is compared to the path cost in RSTP.
Example 13-2: Reviewing the RSTP port parameters
ML810(rstp)##
show stp ports
RSTP Port Configuration
-------------------------------------------------------------------------------
Port# Type Priority Path Cost State Des. Bridge Des. Port
-------------------------------------------------------------------------------
01 TP(10/100) 128 2000000 Disabled 00:01
02 TP(10/100) 128 2000000 Disabled 00:02
03 100MB Fiber 128 200000 Disabled 00:03
