Chapter 13 Spanning Tree Protocol
XS1930 Series User’s Guide
146
Hello Time
This is the time interval in seconds between BPDU (Bridge Protocol Data Units) configuration
message generations by the root switch. The allowed range is 1 to 10 seconds.
Max Age
This is the maximum time (in seconds) the Switch can wait without receiving a BPDU before
attempting to reconfigure. All Switch ports (except for designated ports) should receive BPDUs
at regular intervals. Any port that ages out STP information (provided in the last BPDU)
becomes the designated port for the attached LAN. If it is a root port, a new root port is
selected from among the Switch ports attached to the network. The allowed range is 6 to 40
seconds.
Forwarding Delay
This is the maximum time (in seconds) the Switch will wait before changing states. This delay is
required because every switch must receive information about topology changes before it
starts to forward frames. In addition, each port needs time to listen for conflicting information
that would make it return to a blocking state; otherwise, temporary data loops might result.
The allowed range is 4 to 30 seconds. As a general rule:
Note: 2 * (Forward Delay - 1) >= Max Age >= 2 * (Hello Time + 1)
Maximum hops
Enter the number of hops (between 1 and 255) in an MSTP region before the BPDU is discarded
and the port information is aged.
Configuration
Name
Enter a descriptive name (up to 32 characters) of an MST region.
Revision Number
Enter a number to identify a region’s configuration. Devices must have the same revision
number to belong to the same region.
Apply
Click
Apply
to save your changes to the Switch’s run-time memory. The Switch loses these
changes if it is turned off or loses power, so use the
Save
link on the top navigation panel to
save your changes to the non-volatile memory when you are done configuring.
Cancel
Click
Cancel
to begin configuring this screen afresh.
Instance
Use this section to configure MSTI (Multiple Spanning Tree Instance) settings.
Instance
Enter the number you want to use to identify this MST instance on the Switch.
Note: The Switch supports instance numbers 0-16.
Bridge Priority
Set the priority of the Switch for the specific spanning tree instance. The lower the number, the
more likely the Switch will be chosen as the root bridge within the spanning tree instance.
Enter priority values between 0 and 61440 in increments of 4096 (thus valid values are 4096,
8192, 12288, 16384, 20480, 24576, 28672, 32768, 36864, 40960, 45056, 49152, 53248, 57344 and
61440).
VLAN Range
Enter the start of the VLAN ID range that you want to add or remove from the VLAN range edit
area in the
Start
field. Enter the end of the VLAN ID range that you want to add or remove
from the VLAN range edit area in the
End
field.
Next click:
•
Add
- to add this range of VLAN(s) to be mapped to the MST instance.
•
Remove
- to remove this range of VLAN(s) from being mapped to the MST instance.
•
Clear
- to remove all VLAN(s) from being mapped to this MST instance.
Enabled VLAN(s)
This field displays which VLAN(s) are mapped to this MST instance.
Port
This field displays the port number. * means all ports.
*
Settings in this row apply to all ports.
Use this row only if you want to make some settings the same for all ports. Use this row first to set
the common settings and then make adjustments on a port-by-port basis.
Note: Changes in this row are copied to all the ports as soon as you make them.
Active
Select this check box to add this port to the MST instance.
Table 65 Advanced Application > Spanning Tree Protocol > MSTP (continued)
LABEL
DESCRIPTION
