Brocade FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide - Manual (Page 268)

To exclude a contiguous (unbroken) range of ports from Fast Span, enter commands such as the
following.
device(config)#fast port-span exclude ethernet 1 to 24
device(config)#write memory
Syntax: [no] fast port-span [ exclude ethernet port [ethernet port] | to [port]]
To re-enable Fast Port Span on a port, enter a command such as the following.
device(config)#no fast port-span exclude ethernet 1
device(config)#write memory
This command re-enables Fast Port Span on port 1 only and does not re-enable Fast Port Span on
other excluded ports. You also can re-enable Fast Port Span on a list or range of ports using the
syntax shown above this example.
To re-enable Fast Port Span on all excluded ports, disable and then re-enable Fast Port Span by
entering the following commands.
device(config)#no fast port-span
device(config)#fast port-span
device(config)#write memory
Disabling and then re-enabling Fast Port Span clears the exclude settings and thus enables Fast Port
Span on all eligible ports. To make sure Fast Port Span remains enabled on the ports following a
system reset, save the configuration changes to the startup-config file after you re-enable Fast Port
Span. Otherwise, when the system resets, those ports will again be excluded from Fast Port Span.
Fast Uplink Span
The Fast Port Span feature described in the previous section enhances STP performance for end
stations. The Fast Uplink Span feature enhances STP performance for wiring closet switches with
redundant uplinks. Using the default value for the standard STP forward delay, convergence following
a transition from an active link to a redundant link can take 30 seconds (15 seconds for listening and
an additional 15 seconds for learning).
You can use the Fast Uplink Span feature on a Brocade device deployed as a wiring closet switch to
decrease the convergence time for the uplink ports to another device to just one second. The new
Uplink port directly goes to forward mode (bypassing listening and learning modes). The wiring closet
switch must be a Brocade device but the device at the other end of the link can be a Brocade device
or another vendor’s switch.
Configuration of the Fast Uplink Span feature takes place entirely on the Brocade device. To configure
the Fast Uplink Span feature, specify a group of ports that have redundant uplinks on the wiring closet
switch (Brocade device). If the active link becomes unavailable, the Fast Uplink Span feature
transitions the forwarding to one of the other redundant uplink ports in just one second. All Fast Uplink
Span-enabled ports are members of a single Fast Uplink Span group.
NOTE
To avoid the potential for temporary bridging loops, Brocade recommends that you use the Fast Uplink
feature only for wiring closet switches (switches at the edge of the network cloud). In addition, enable
the feature only on a group of ports intended for redundancy, so that at any given time only one of the
ports is expected to be in the forwarding state.
Fast Uplink Span
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