Motorola WS5100 Series Reference Manual page 199

Error Disable Timeout Select this option to enable an error disable-timeout facility. The error disable-
ID Format Selector
Portfast Bdpu Filter
PortFast Bdpu Guard
Admin Cisco Mode
Operator Cisco Mode Displays whether Cisco's version of MSTP is running. This is not a configurable
MST Config Digest
4. Refer to the General Configuration
CIST Root
External Root Cost
Regional Root
CIST Bridge Priority
CIST Bridge HelloTime Set the CIST Hello Time (in seconds). After the defined interval all bridges in a
Bridge Hello Time
CIST Bridge Forward
Delay
timeout is used to set a timeout value for ports disabled resulting from a BPDU
guard.
The BPDU guard feature shuts down the port on receiving a BPDU on a BPDU-guard
enabled port.
Enter the format selector value of the Configuration Identifier.
Select this checkbox to enable a portfast BPDU filter for the port.
The Spanning Tree Protocol sends BPDUs from all the ports. Enabling the BPDU
filter feature ensures PortFast enabled ports do not transmit or receive any BPDUs.
Select this checkbox to enable the PortFast BPDU Guard on the bridge.
When the BPDU Guard feature is set for bridge, all portfast-enabled ports of the
bridge that have BPDU set to default shutdown the port on receiving a BPDU. Hence
no BPDUs are processed.
Select this checkbox to enable interoperability with Cisco's version of MSTP, which
is incompatible with standard MSTP.
parameter.
Displays the Configuration Digest derived from the MST Configuration table.
field for the following
This displays the CIST (Common Internal Spanning Tree) root MAC address.
The CIST root is the master region to which other root regions are associated.
The lower the path cost, the greater the likelihood of the bridge becoming the root.
Displays the root cost of the CIST root.
This displays the regional roots MAC address.
Set the bridge priority for the common instance. The value entered, determines the
likelihood the instance is selected as the root.
The lower the priority the greater the likelihood of the bridge becoming a root.
bridged LAN exchange BPDUs.
The hello time is the time interval (in seconds) the device waits between BPDU
transmissions.
If this is the root bridge, the value is equal to the configured Hello Time.
A very low value leads to excessive traffic on the network, whereas a higher value
delays the detection of a topology change. This value is used by all instances.
Displays the configured Hello Time.
Enter the CIST bridge forward delay value received from the root bridge. If this is
the root bridge, the value will be equal to the Configured Forward Delay.
The forward delay value is the maximum time (in seconds) the root device waits
before changing states (from a listening state to a learning state to a forwarding
state).
This delay is required, as every device must receive information about topology
changes before forwarding 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 may result.
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Network Setup