Brocade Network OS Administrator’s Guide v4.1.1 - Manual (Page 426)

Enabling a port (interface) as an edge port (DCB)
From the DCB interface, use this command to enable the port as an edge port to allow the port to
quickly transition to the forwarding state.
NOTE
This command is only for RSTP and MSTP. Use the spanning-tree portfast command for STP (refer
to
Enabling port fast (DCB) on page 428).
Follow these guidelines to configure a port as an edge port:
• A port can become an edge port if no BPDU is received.
• When an edge port receives a BPDU, it becomes a normal spanning tree port and is no longer an
edge port.
• Because ports that are directly connected to end stations cannot create bridging loops in the
network, edge ports transition directly to the forwarding state and skip the listening and learning
states.
To enable the DCB interface as an edge port, run the following steps in privileged EXEC mode.
1. Enter the configure terminal command to access global configuration mode.
2. Enter the interface command to specify the DCB interface type and slot/port number.
The gigabitethernet rbridge-id/slot/port operand is used only for the Brocade VDX 6710, Brocade
VDX 8770-4, and Brocade VDX 8770-8. The prompt for these ports is in the format: switch(config-if-
gi-22/0/1)#.
switch(config)# interface tengigabitethernet 0/1
3. Enter the no shutdown command to enable the DCB interface.
switch(conf-if-te-0/1)# no shutdown
4. Enter the spanning-tree command to enable the DCB interface as an edge port.
switch(conf-if-te-0/1)# spanning-tree edgeport
Enabling guard root (DCB)
From the DCB interface, use this command to enable the guard root feature on the switch. This
feature provides a way to enforce the root bridge placement in the network. With guard root enabled
on an interface, the switch is able to restrict which interface is allowed to be the spanning tree root port
or the path to the root for the switch. The root port provides the best path from the switch to the root
switch. By default, guard root is disabled.
Guard root protects the root bridge from malicious attacks and unintentional misconfigurations where a
bridge device that is not intended to be the root bridge becomes the root bridge. This causes severe
bottlenecks in the data path. Guard root ensures that the port on which it is enabled is a designated
port. If the guard-root-enabled port receives a superior BPDU, it goes to a discarding state.
Additionally, you may enable guard root for a specific VLAN. If the VLAN parameter is not provided,
the priority value is applied globally for all per-VLAN instances. However, for the VLANs that have
been configured explicitly, the per-VLAN configuration takes precedence over the global configuration.
On the Brocade VDX 8770, the VLAN value can be 1 through 4086. VLAN IDs 4087 through 4094 are
internally reserved VLAN IDs. On all other Brocade VDX switches, the VLAN value can be 1
through 3962, as 3963 through 4094 are reserved.
To enable guard root on a DCB interface, perform the following steps from privileged EXEC mode.
1. Enter the configure terminal command to access global configuration mode.
2. Enter the interface command to specify the DCB interface type and slot/port number.
Enabling a port (interface) as an edge port (DCB)
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