Installation guide

Network Setup
4-123
4. Refer to the General Configuration field for the following
MST Revision Level Assign a MST revision level number to the MST region to which the
device belongs. Each switch running is configured with a unique
MST name and revision number. This helps when the switch has
different VLANs that belong to different MSTP regions. The MST
Revision Level specifies the revision level MSTP.
Error Disable Timeout Select this option to enable an error disable-timeout facility. The
error disable-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.
ID Format Selector Enter the format selector value of the Configuration Identifier.
Portfast Bdpu Filter 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.
PortFast Bdpu Guard 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.
Admin Cisco Mode Select this checkbox to enable interoperability with Cisco’s version
of MSTP, which is incompatible with standard MSTP.
Operator Cisco Mode Displays whether Cisco’s version of MSTP is running. This is not a
configurable parameter.
MST Config Digest Displays the Configuration Digest derived from the MST
Configuration table.
CIST Root 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.
External Root Cost Displays the root cost of the CIST root.
Regional Root This displays the regional roots MAC address.
CIST Bridge Priority 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.