Configuring Fast Hellos For Link State Detection - Dell S4820T Configuration Manual

CAUTION: Configure EdgePort only on links connecting to an end station. If you enable EdgePort
on an interface connected to a network, it can cause loops.
Dell Networking OS Behavior: Regarding bpduguard shutdown-on-violation behavior:
• If the interface to be shut down is a port channel, all the member ports are disabled in the hardware.
• 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).
• The reset linecard command does not clear the Error Disabled state of the port or the hardware
disabled state. The interface continues to be disables in the hardware.
• You can clear the Error Disabled state with any of the following methods:
– Perform an shutdown command on the interface.
– Disable the shutdown-on-violation command on the interface (the no spanning-tree
stp-id portfast [bpduguard | [shutdown-on-violation]] command).
– Disable spanning tree on the interface (the no spanning-tree command in INTERFACE mode).
– Disable global spanning tree (the no spanning-tree command in CONFIGURATION mode).
To enable EdgePort on an interface, use the following command.
• Enable EdgePort on an interface.
INTERFACE mode
spanning-tree rstp edge-port [bpduguard | shutdown-on-violation]
Example of Verifying an EdgePort is Enabled on an Interface
To verify that EdgePort is enabled on a port, use the show spanning-tree rstp command from EXEC
privilege mode or the show config command from INTERFACE mode.
NOTE: Dell Networking recommends using the show config command from INTERFACE mode.
In the following example, the bold line indicates that the interface is in EdgePort mode.
Dell(conf-if-te-2/1)#show config
!
interface TenGigabitEthernet 2/1
no ip address
switchport
spanning-tree rstp edge-port
shutdown
Dell(conf-if-te-2/1)#

Configuring Fast Hellos for Link State Detection

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.
852
Rapid Spanning Tree Protocol (RSTP)