Edge-Core ECS4810-12M Layer 2, Management Manual

Page: 222 / 1236

C
HAPTER
8
| Spanning Tree Algorithm
Configuring Global Settings for STA
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new root port is selected from among the device ports attached to the
network. (References to “ports” in this section mean “interfaces,” which
includes both ports and trunks.)
■
Default: 20
■
Minimum: The higher of 6 or [2 x (Hello Time + 1)]
■
Maximum: The lower of 40 or [2 x (Forward Delay - 1)]
◆
Forward Delay – The maximum time (in seconds) this device will wait
before changing states (i.e., discarding to learning to forwarding). This
delay is required because every device 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 discarding state; otherwise, temporary data loops might
result.
■
Default: 15
■
Minimum: The higher of 4 or [(Max. Message Age / 2) + 1]
■
Maximum: 30
Configuration Settings for MSTP
◆ Max Instance Numbers – The maximum number of MSTP instances
to which this switch can be assigned.
◆ Configuration Digest – An MD5 signature key that contains the VLAN
ID to MST ID mapping table. In other words, this key is a mapping of all
VLANs to the CIST.
◆
Region Revision
3
– The revision for this MSTI. (Range: 0-65535;
Default: 0)
◆
Region Name
3
– The name for this MSTI. (Maximum length: 32
characters; switch’s MAC address)
◆
Max Hop Count – The maximum number of hops allowed in the MST
region before a BPDU is discarded. (Range: 1-40; Default: 20)
W
EB
I
NTERFACE
To configure global STA settings:
1.
Click Spanning Tree, STA.
2.
Select Configure Global from the Step list.
3.
Select Configure from the Action list.
4.
Modify any of the required attributes. Note that the parameters
displayed for the spanning tree types (STP, RSTP, MSTP) varies as
described in the preceding section.
5.
Click Apply
3. The MST name and revision number are both required to uniquely identify an MST region.