Brocade Communications Systems 53-1001761-01 manual Configuring Rstp on Brocade FCoE hardware

5 RSTP overview

With RSTP, the port roles for the new interface states are also different. RSTP differentiates explicitly between the state of the port and the role it plays in the topology. RSTP uses the root port and designated port roles defined by STP, but splits the blocked port role into backup port and alternate port roles:

•Backup port—Provides a backup for the designated port and can only exist where two or more ports of the switch are connected to the same LAN; the LAN where the bridge serves as a designated switch.

•Alternate port—Serves as an alternate port for the root port providing a redundant path towards the root bridge.

Only the root port and the designated ports are part of the active topology; the alternate and backup ports do not participate in it.

When the network is stable, the root and the designated ports are in the forwarding state, while the the alternate and backup ports are in the discarding state. When there is a topology change, the new RSTP port roles allow a faster transition of an alternate port into the forwarding state.

For more information on RSTP, see “STP, RSTP, and MSTP configuration and management” on page 51.

Configuring RSTP on Brocade FCoE hardware

The basic process for configuring RSTP on your Brocade FCoE hardware is as follows.

1.Enter Global Configuration mode.

2.Enable RSTP using the global protocol spanning-treecommand. For details, see “Enabling STP, RSTP, or MSTP” on page 51.

switch(config)#protocol spanning-tree rstp

3.Designate the root switch using the bridge-prioritycommand. For details, see “Specifying the bridge priority” on page 52. The range is 0 through 61440 and the priority values can be set only in increments of 4096.

switch(conf-stp)#bridge-priority 28582

4.Configure the bridge forward delay value. For details, see “Specifying the bridge forward delay” on page 52.

switch(conf-stp)#forward-delay 20

5.Configure the bridge maximum aging time value. For details, see “Specifying the bridge maximum aging time” on page 53.

switch(conf-stp)#max-age 25

6.Enable the error disable timeout timer value. For details, see “Enabling the error disable timeout timer” on page 53.

switch(conf-stp)#error-disable-timeout enable

7.Configure the error-disable-timeoutinterval value. For details, see “Specifying the error disable timeout interval” on page 53.

8.switch(conf-stp)#error-disable-timeout interval 60

9.Configure the port-channel path cost. For details, see “Specifying the port-channel path cost” on page 54.

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

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