3Com 5500-SI Switch User Manual


 
552 CHAPTER 26: RSTP CONFIGURATION
By default, an Ethernet port can transmit at most 3 STP packets within one Hello
Time.
Set Specified Port to be
an EdgePort
EdgePort is not connected to any Switch directly or indirectly using the connected
network.
You can use the following command to set a specified port as an EdgePort.
Perform the following configurations in Ethernet Port View.
Table 607 Set Specified Port as the EdgePort
In the process of recalculating the spanning tree, the EdgePort can transfer to the
forwarding state directly and reduce unnecessary transition time. If the current
Ethernet port is not connected with any Ethernet port of other bridges, this port
should be set as an EdgePort. If a specified port connected to a port of any other
bridge is configured as an edge port, RSTP will automatically detect and reconfigure it
as a non-EdgePort.
After the network topology changed, if a configured non-EdgePort changes to an
EdgePort and is not connected to any other port, it is recommended to configure it as
an EdgePort manually because RSTP cannot configure a non-EdgePort as an EdgePort
automatically.
Configure the port directly connected to the terminal as an EdgePort, so that the port
can transfer immediately to the forwarding state.
By default, all the Ethernet ports are configured as non-EdgePort.
Specifying the Path Cost
on a Port
Path Cost is a parameter related with the link rate.
Specify the Path Cost on a Port
You can specify the Path Cost on a port by using the following commands.
Perform the following configuration in Ethernet Interface View.
Table 608 Specifying the Path Cost on a Port
The path cost on an Ethernet port is related to the transmission rate of the link the
port connects to. The larger the link rate is, the smaller the path cost shall be. RSTP
can automatically detect the link rate and calculate the path cost for the current
Ethernet port. The configuration of path cost brings about the re-calculation of the
spanning tree. It is recommended to adopt the default value, with which RSTP will
automatically calculate the path cost of the current port.
By default, the Switch calculates the path cost directly from the link rate.
Operation Command
Set a specified port as an EdgePort or a non-EdgePort stp edged-port { enable |
disable }
Set the specified port as the non-EdgePort, as defaulted undo stp edged-port
Operation Command
Specify the Path Cost on a port stp cost cost
Restore the default Path Cost on the port undo stp cost