XG700 User's Guide
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5.10.11 spanning-tree portfast
Function
The “portfast” function reduces the time required to reconfigure the STP topology.
When the function detects a link down of the root port in the spanning tree, it skips the topology recalculation and directly
switches from the blocking status to the forwarding status. When switched to the forwarding status, the MAC address of the
terminal locating under the switch is sent as the dummy multicast frame having the source MAC address and the MAC address
table of the host switch is changed.
This function can be used only for an edge port which is directly connected to the end station.
Use the no form to return to the default setup.
Prompt
xg(config-if)#, or xg(config-agg)#
Command syntax
spanning-tree portfast
no spanning-tree portfast
Parameter
portfast
Enables the portfast function.
Command type
Configuration command
Default
None
Message
% port %1$ is membership of uplink-domain %2$.
Explanation
The specified port already belongs to an uplink domain.
[[Inserted string]]%1$: specified port number
[[Inserted string]]%2$: uplink domain number
Solution
Specify a port not belonging to any uplink domains. Or remove the port from an uplink domain.
Note
Use this function only for the port to be connected as an edge switch or for the port directly connected to the end
station.
If this function is used for others, a frame may be looped due to the topology loop and, therefore, the switch and
network operations may be affected.
The port has to be removed from an uplink domain before disabling STP portfast function.
Example
Enable portfast for switch port 2.
xg(config)# interface port 2
xg(config)# spanning-tree portfast
