Brocade Communications Systems 53-1001761-01 manual Specifying the port-channel path cost

5 STP, RSTP, and MSTP configuration and management

Specifying the port-channel path cost

In any mode (STP, RSTP, or MSTP), use this command to specify the port-channel path cost. The default port cost is standard. The path cost options are:

•custom—Specifies that the path cost changes according to the port-channel’s bandwidth.

•standard—Specifies that the path cost does not change according to the port-channel’s bandwidth.

To specify the port-channel path cost, perform the following steps from Privileged EXEC mode.

1.Enter the configure terminal command to access global configuration mode.

2.Enter the protocol command to enable STP, RSTP, or MSTP.

switch(config)#protocol spanning-tree stp

3. Specify the port-channel path cost.

switch(conf-stp)#port-channel path-cost custom

Specifying the bridge hello time (STP and RSTP)

In STP or RSTP mode, use this command to configure the bridge hello time. The hello time determines how often the switch interface broadcasts hello Bridge Protocol Data Units (BPDUs) to other devices.The range is 1 through 10 seconds. The default is 2 seconds.

When configuring the hello-time, the max-age setting must be greater than the hello-time setting. The following relationship should be kept:

2*(forward_delay - 1)>=max_age>=2*(hello_time + 1)

To specify the bridge hello time, perform the following steps from Privileged EXEC mode.

1.Enter the configure terminal command to access global configuration mode.

2.Enter the protocol command to enable STP, RSTP, or MSTP.

switch(config)#protocol spanning-tree stp

3.Specify the time range in seconds for the interval between the hello BPDUs sent on an interface.

switch(conf-stp)#hello-time 5

Specifying the transmit hold count (RSTP and MSTP)

In RSTP and MSTP mode, use this command to configure the BPDU burst size by specifying the transmit hold count value. The command configures the maximum number of BPDUs transmitted per second for RSTP and MSTP before pausing for 1 second. The range is 1 through 10. The default is 6 seconds.

To specify the transmit hold count, perform the following steps from Privileged EXEC mode.

1.Enter the configure terminal command to access global configuration mode.

2.Specify the transmit hold count.

switch(config)#transmit-holdcount 5

54	Converged Enhanced Ethernet Administrator’s Guide
	53-1001761-01