ZyXEL Communications XGS4600 Series User Manual page 166

Table 62 Advanced Application > Spanning Tree Protocol > MSTP (continued)
LABEL DESCRIPTION
MaxAge This is the maximum time (in seconds) a 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) a 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
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 Enter a descriptive name (up to 32 characters) of an MST region.
Name
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. The Switch
supports instance numbers 0 – 15.
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 VLANs to be mapped to the MST instance.
• Remove – to remove this range of VLANs from being mapped to the MST instance.
• Clear – to remove all VLANs from being mapped to this MST instance.
Enabled VLAN(s) This field displays which VLANs are mapped to this MST instance.
Port This field displays the port number. In stacking mode, the first number represents the slot ID and
the second is the port number.
* 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.
Chapter 13 Spanning Tree Protocol
1) >= Max Age >= 2 * (Hello Time + 1)
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XGS4600 Series User's Guide
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