Dell PowerConnect B-RX Configuration Manual page 454

13
Configuring RSTP parameters
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Configuring a fast uplink port group
To enable Fast Uplink, use the following method.
Using the CLI
To configure a group of ports for Fast Uplink Span, enter the following commands.
BigIron RX(config)# fast uplink-span ethernet 4/1 to 4/4
BigIron RX(config)# write memory
Syntax: [no] fast uplink-span [ethernet <portnum> [ethernet <portnum>... | to <portnum>]]
This example configures four ports, 4/1 – 4/4, as a Fast Uplink Span group. In this example, all
four ports are connected to a wiring closet switch. Only one of the links is expected to be active at
any time. The other links are redundant. For example, if the link on port 4/1 is the active link on
the wiring closet switch but becomes unavailable, one of the other links takes over. Because the
ports are configured in a Fast Uplink Span group, the STP convergence takes about four seconds
instead of taking 30 seconds or longer using the standard STP forward delay.
If you add a port that is the primary port of a trunk group, all ports in the trunk group become
members of the Fast Uplink Span group.
You can add ports to a Fast Uplink Span group by entering the fast uplink-span command
additional times with additional ports. The device can have only one Fast Uplink Span group, so all
the ports you identify as Fast Uplink Span ports are members of the same group.
To remove a Fast Uplink Span group or to remove individual ports from a group, use "no" in front of
the appropriate fast uplink-span command. For example, to remove ports 4/3 and 4/4 from the
Fast Uplink Span group configured above, enter the following commands.
BigIron RX(config)# no fast uplink-span ethernet 4/3 to 4/4
BigIron RX(config)# write memory
If you delete a port that is the primary port of a trunk group, all ports in the trunk group are
removed from the Fast Uplink Span group.
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When the original working trunk group comes back (partially or fully), the transition back to the
original topology is accelerated if the conditions listed above are met.
BigIron RX Series Configuration Guide
53-1001810-01