Brocade Communications Systems 53-1002163-02 manual Configuring Spanning Tree Protocol

5 Configuring Spanning Tree Protocol

Configuring Spanning Tree Protocol

Spanning Tree Protocol (STP) is a mechanism to detect and avoid loops in Ethernet networks by establishing a fixed path between all the switches in a LAN. The Brocade FCoE hardware supports three spanning tree variations: standard Spanning Tree Protocol (STP), Rapid Spanning Tree Protocol (RSTP), and Multiple Spanning Tree Protocol (MSTP).

NOTE

Configuring Spanning Tree on a port enabled for FCoE is not recommended, as it can cause login issues while the port transitions from the blocked state to the forwarding state. Either STP should be disabled, or configured in edge mode. However, Brocade strongly recommends that STP be disabled.

It is a best practice that an access layer switch does not become the root switch. Changing the bridge or STP priority helps to ensure that this does not occur. The following example performed from the CEE CLI configures the switch for RSTP and sets the bridge priority to the highest value, ensuring it will not become the root switch in an existing LAN.

To configure RSTP, perform the following steps in global configuration mode.

1. Configure the switch for RSTP.

switch(config)#protocol spanning-tree rstp

2.Set the bridge priority to the highest value so it does not become the root switch in an existing LAN.

switch(conf-rstp)#bridge-priority 61440

3. Enter the copy command to save the running-configfile to the startup-configfile.

switch(conf-rstp)#do copy running-config startup-config

Configuring VLAN membership

IEEE 802.1q Virtual LANs (VLANs) provide the capability to overlay the physical network with multiple virtual networks. VLANs allow network traffic isolation into separate virtual networks, reducing the size of administrative and broadcast domains.

A VLAN contains end stations that have a common set of requirements which can be in independent physical locations. You can group end stations in a VLAN even if they are not physically located in the same LAN segment. VLANs are typically associated with IP subnets and all the end stations in a particular IP subnet belong to the same VLAN.

In addition to creating a special VLAN for FCoE traffic, VLAN classifiers are applied to incoming EtherTypes for FCoE Initialization Protocol (FIP) and FCoE. VLAN classifiers are rules used to dynamically classify Ethernet frames on an untagged interface to VLANs.

NOTE

FIP and FCoE cannot be manually configured in VLAN classifier rules. They are part of the fcoeport interface configuration and are applied automatically when an interface is configured as an fcoeport.

38	Converged Enhanced Ethernet Administrator’s Guide
	53-1002163-02