Foundry NetIron M2404C and M2404F Metro Access Switches
Configuring RSTP (Rev. 03)
Rapid Spanning Tree Protocol (RSTP)
© 2008 Foundry Networks, Inc.
Page 19 of 34
Argument Description
priority
RSTP priority value in range 0 (highest priority) to 240 (lowest priority),
assigned to the configured interface in increments of 16. Any other number will
be rounded down. The default value is 128 (IEEE802.1w).
Forcing a Port to Work by the RSTP Protocol
The
rapid-spanning-tree detect-protocols
command, in Interface Configuration mode, forces the
port to work by the Rapid Spanning Tree Protocol (RSTP) and not by the Spanning Tree Protocol
(STP).
A device running RSTP supports a built-in protocol migration mechanism that enables RSTP to
interoperate with legacy 802.1D STP.
When an RSTP switch receives a legacy 802.1D configuration BPDU (BPDU with protocol
version 0) it starts transmitting legacy 802.1D BPDUs (configuration messages and TCN
messages). However, when the switch stops receiving BPDUs it cannot automatically revert to the
RSTP mode because the switch cannot determine whether the legacy switch has been removed
from that link unless the legacy switch is a designated switch.
The RSTP supports a mechanism that forces the port to restart a protocol migration process (force
the re-negotiation with neighboring switches) by means of:
1. CLI command
rapid-spanning-tree detect-protocols
.
2. A link up event.
Command Syntax
device-name
(config-if
UU/SS/PP
)#
rapid-spanning-tree detect-protocols
Restoring the RSTP Interface Parameters to Their Defaults
The
rapid-spanning-tree defaults
command, in Interface Configuration mode, restores the RSTP
parameters to their default values for the configured interface.
Command Syntax
device-name
(config-if
UU/SS/PP
)#
rapid-spanning-tree defaults
RSTP Display Commands
Table 7
lists the RSTP display commands.
Table 7: RSTP Display Commands
Command
Description
rapid-spanning-tree
Displays the current RSTP parameter configuration.