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○ When you add a physical port to a port channel already in the Error Disable state, the new member port is also disabled in
the hardware.
○ When you remove a physical port from a port channel in the Error Disable state, the error disabled state is cleared on this
physical port (the physical port is enabled in the hardware).
○ You can clear the Error Disabled state with any of the following methods:
￭ Use the shutdown command on the interface.
￭ Disable the shutdown-on-violation command on the interface (using the no spanning-tree stp-id
portfast [bpduguard | [shutdown-on-violation]] command).
￭ Disable spanning tree on the interface (using the no spanning-tree command in INTERFACE mode).
￭ Disabling global spanning tree (using the no spanning-tree command in CONFIGURATION mode).
To verify that EdgePort is enabled, use the show config command from INTERFACE mode.
Dell(conf-if-Te-3/41)#spanning-tree mstp edge-port
Dell(conf-if-Te-3/41)#show config
!
interface TenGigabitEthernet 3/41
no ip address
switchport
spanning-tree mstp edge-port
spanning-tree MSTI 1 priority 144
no shutdown
Dell(conf-if-Te-3/41)#
Configuring Fast Hellos for Link State Detection
Use RSTP fast hellos to achieve sub-second link-down detection so that convergence is triggered faster. The standard RSTP
link-state detection mechanism does not offer the same low link-state detection speed.
To achieve sub-second link-down detection so that convergence is triggered faster, use RSTP fast hellos. The standard RSTP
link-state detection mechanism does not offer the same low link-state detection speed.
RSTP fast hellos decrease the hello interval to the order of milliseconds and all timers derived from the hello timer are adjusted
accordingly. This feature does not inter-operate with other vendors, and is available only for RSTP.
● Configure a hello time on the order of milliseconds.
PROTOCOL RSTP mode
hello-time milli-second interval
The range is from 50 to 950 milliseconds.
DellEMC(conf-rstp)#do show spanning-tree rstp brief
Executing IEEE compatible Spanning Tree Protocol
Root ID Priority 0, Address 0001.e811.2233
Root Bridge hello time 50 ms, max age 20, forward delay 15
Bridge ID Priority 0, Address 0001.e811.2233
We are the root
Configured hello time 50 ms, max age 20, forward delay 15
NOTE:
The hello time is encoded in BPDUs in increments of 1/256ths of a second. The standard minimum hello time
in seconds is 1 second, which is encoded as 256. Millisecond. hello times are encoded using values less than 256; the
millisecond hello time equals (x/1000)*256. When you configure millisecond hellos, the default hello interval of 2 seconds is
still used for edge ports; the millisecond hello interval is not used.
Flush MAC Addresses after a Topology Change
Dell Networking OS has an optimized MAC address flush mechanism for RSTP, MSTP, and PVST+ that flushes addresses only
when necessary, which allows for faster convergence during topology changes.
However, you may activate the flushing mechanism defined by 802.1Q-2003 using the tc-flush-standard command, which
flushes MAC addresses after every topology change notification.
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Multiple Spanning Tree Protocol (MSTP)