500.bok : 50003 55 Fri Sep 11 14:52:16 1998
55
C H A P T E R 3 Standard Configuration
•
Time between transmitted Configuration BPDUs
•
Time the switch spends in the Listening and Learning states
Warning when using
VLANs
It is important to be aware of problems that may arise when using
Spanning Tree and VLANs. The Spanning Tree can use alternative
paths (such as different ports) to get messages to their destination.
The diagram above, shows two switches. On the left, we see the two
switches connected and the ports are grouped in two VLANs: A and
B. On the right, we have enabled STP; STP blocks the path between
X and Z (to avoid looping) and, therefore, destroys the VLAN setup
(because VLAN B needs these ports to receive messages).
Why change these from
their defaults?
The switch is delivered with Spanning Tree default values set to those
recommended by the IEEE 802.1d standard. These values are conser-
vative worst-case estimates for LANs consisting of a large number of
switches. Therefore, changing these default values may improve the
performance of your network.
Power
Intel Express
550T Routing
Switch
Status
Temperature
RPS
123 87654
Reset
Console
9600-8-N-1
Slot BSlot A
Blink
Solid
Solid
Off
Activity
Link
100 Mbps
10 Mbps
Collision
Disabled
Full duplex
Half duplex
LEDs
LEDs
Green
Green
Orange
Orange
Port Status
Power
Intel Express
550T Routing
Switch
Status
Temperature
RPS
123 87654
Reset
Console
9600-8-N-1
Slot BSlot A
Blink
Solid
Solid
Off
Activity
Link
100 Mbps
10 Mbps
Collision
Disabled
Full duplex
Half duplex
LEDs
LEDs
Green
Green
Orange
Orange
Port Status
Power
Intel Express
550T Routing
Switch
Status
Temperature
RPS
123 87654
Reset
Console
9600-8-N-1
Slot BSlot A
Blink
Solid
Solid
Off
Activity
Link
100 Mbps
10 Mbps
Collision
Disabled
Full duplex
Half duplex
LEDs
LEDs
Green
Green
Orange
Orange
Port Status
Power
Intel Express
550T Routing
Switch
Status
Temperature
RPS
123 87654
Reset
Console
9600-8-N-1
Slot BSlot A
Blink
Solid
Solid
Off
Activity
Link
100 Mbps
10 Mbps
Collision
Disabled
Full duplex
Half duplex
LEDs
LEDs
Green
Green
Orange
Orange
Port Status
Switch 2
Switch 1
B
B
A
A
WX
Y
Z
VLAN STP
VLAN
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