Spanning tree protocol (stp) – Brocade FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide User Manual
Page 364
• In addition to the default tag type 0x8100, you can now configure one additional global tag profile
with a number from 0xffff.
• Tag profiles on a single port, or a group of ports can be configured to point to the global tag profile.
For example applications and configuration details, refer to
406.
To configure a global tag profile, enter the following command in the configuration mode.
device(config)# tag-profile 9500
Syntax: [no] tag-profile tag-no
tag-no - the number of the tag, can be 0x8100 (default), or 0xffff
To direct individual ports or on a range of ports to this tag profile, enter commands similar to the
following.
device(config)# interface ethernet 1/1/1
device(config-if-e1000-1/1/1)# tag-profile enable
device(config-mif-1/1/1,1/2/1)# tag-profile enable
Spanning Tree Protocol (STP)
The default state of STP depends on the device type:
• STP is disabled by default on Brocade Layer 3 Switches.
• STP is enabled by default on Brocade Layer 2 Switches.
Also by default, each port-based VLAN has a separate instance of STP. Thus, when STP is globally
enabled, each port-based VLAN on the device runs a separate spanning tree.
You can enable or disable STP on the following levels:
• Globally - Affects all ports on the device.
NOTE
If you configure a port-based VLAN on the device, the VLAN has the same STP state as the default
STP state on the device. Thus, on Layer 2 Switches, new VLANs have STP enabled by default. On
Layer 3 Switches, new VLANs have STP disabled by default. You can enable or disable STP in
each VLAN separately. In addition, you can enable or disable STP on individual ports.
• Port-based VLAN - Affects all ports within the specified port-based VLAN.
STP is a Layer 2 protocol. Thus, you cannot enable or disable STP for individual protocol VLANs or for
IP subnet, IPX network, or AppleTalk cable VLANs. The STP state of a port-based VLAN containing
these other types of VLANs determines the STP state for all the Layer 2 broadcasts within the port-
based VLAN. This is true even though Layer 3 protocol broadcasts are sent on Layer 2 within the
VLAN.
It is possible that STP will block one or more ports in a protocol VLAN that uses a virtual routing
interface to route to other VLANs. For IP protocol and IP subnet VLANs, even though some of the
physical ports of the virtual routing interface are blocked, the virtual routing interface can still route so
long as at least one port in the virtual routing interface protocol VLAN is not blocked by STP.
If you enable Single STP (SSTP) on the device, the ports in all VLANs on which STP is enabled
become members of a single spanning tree. The ports in VLANs on which STP is disabled are
excluded from the single spanning tree.
For more information, refer to
on page 251.
Spanning Tree Protocol (STP)
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FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide
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