Reference Guide

Multiple Spanning Tree Protocol (MSTP) | 951
Enabling Portfast BPDU guard and loop guard at the same time on a port results in a port that remains
in a blocking state and prevents traffic from flowing through it. For example, when Portfast BPDU
guard and loop guard are both configured:
• If a BPDU is received from a remote device, BPDU guard places the port in an err-disabled
blocking state and no traffic is forwarded on the port.
• If no BPDU is received from a remote device, loop guard places the port in a loop-inconsistent
blocking state and no traffic is forwarded on the port.
tc-flush-standard
c e s
Enable the MAC address flushing upon receiving every topology change notification.
Syntax
tc-flush-standard
To disable, use the no tc-flush-standard command.
Defaults
Disabled
Command Modes
CONFIGURATION
Command
History
Usage
Information
By default FTOS implements an optimized flush mechanism for MSTP. This helps in flushing the
MAC addresses only when necessary (and less often) allowing for faster convergence during topology
changes. However, if a standards-based flush mechanism is needed, this knob command can be turned
on to enable flushing MAC addresses upon receiving every topology change notification.
Version 7.6.1.0 Added support for S-Series
Version 7.5.1.0 Added support for C-Series
Version 6.5.1.0 Introduced