Installation and Getting Started Guide
Fast Uplink Span group on the device. All Fast Uplink Span ports are members of the same Fast Uplink Span group.
NOTE: To avoid the potential for temporary bridging loops,
NOTE: When the wiring closet switch (HP device) first comes up or when STP is first enabled, the uplink ports still must go through the standard STP state transition without any acceleration. This behavior guards against temporary routing loops as the switch tries to determine the states for all the ports. Fast Uplink Span acceleration applies only when a working uplink becomes unavailable.
Fast Uplink Span Rules for Trunk Groups
If you add a port to a Fast Uplink Span group that is a member of a trunk group, the following rules apply:
•If you add the primary port of a trunk group to the Fast Uplink Span group, all other ports in the trunk group are automatically included in the group. Similarly, if you remove the primary port in a trunk group from the Fast Uplink Span group, the other ports in the trunk group are automatically removed from the Fast Uplink Span group.
•You cannot add a subset of the ports in a trunk group to the Fast Uplink Span group. All ports in a trunk group have the same Fast Uplink Span property, as they do for other port properties.
•If the working trunk group is partially down but not completely down, no
•If the working trunk group is completely down, a backup trunk group can go through an accelerated transition only if the following are true:
•The trunk group is included in the fast uplink group.
•All other ports except those in this trunk group are either disabled or blocked. The accelerated transition applies to all ports in this trunk group.
•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.
Configuring a Fast Uplink Port Group
To enable Fast Uplink, use one of the following methods.
USING THE CLI
To configure a group of ports for Fast Uplink Span, enter the following commands:
HP9300(config)# fast
HP9300(config)# write memory
Syntax: [no] fast
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
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