Enhancements in Release F.02.11

Fast-Uplink Spanning Tree Protocol (STP)

To use fast-uplink STP on a Series 2500 switch, configure fast-uplink (Mode = Uplink) only on the switch’s upstream ports; (that is, two or more ports forming a group of redundant links in the direction of the STP root switch). If the active link in this group goes down, fast-uplink STP selects a different upstream port as the root port and resumes moving traffic in as little as ten seconds. The device(s) on the other end of the links must be running STP. However, because fast uplink should be configured only on the Series 2500 switch uplink ports, the device(s) on the other end of the links can be either HP devices or another vendor’s devices, regardless of whether they support fast uplink. For example:

Port A is the STP root port.

 

 

 

 

 

 

C

 

 

 

A

D

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Series 2500

 

 

 

 

 

 

 

 

STP Root Switch

 

LAN

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Switch

B

E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(Wiring Closet,

 

 

 

 

 

 

 

 

 

 

 

 

 

 

or Edge

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Switch)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

• STP is running on both switches.

 

 

 

 

 

 

Port B provides a backup redundant link.

 

STP Blocking

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

that becomes the new STP root port

 

 

 

 

 

 

• Port "A" and port "B" are both configured for

 

 

 

 

 

 

(uplink port) if the link through port A fails.

 

 

 

 

 

 

fast-uplink STP (Mode = Uplink).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 67. Example of How To Implement Fast-Uplink STP

Terminology

TermDefinition

downlink port (downstream port)

edge switch

A switch port that is linked to a port on another switch (or to an end node) that is sequentially further away from the STP root device. For example, port "C" in figure 67, above, is a downlink port.

For the purposes of fast-uplink STP, this is a switch that has no other switches connected to its downlink ports. An edge switch is sequentially further from the root device than other switches to which it is connected. Also termed wiring closet switch or leaf switch. For example, switch "4" in figure 68 (page 150) is an edge switch.

interior switch

In an STP environment, a switch that is sequentially closer to the STP root device than one

 

or more other switches to which it is connected. For example, switches "1", "2", and "3" in

 

figure 68 (page 150) are interior switches.

single-instance spanning

A single spanning-tree ensuring that there are no logical network loops associated with any

tree

of the connections to the switch, regardless of whether there are any VLANs configured on

 

the switch. For more information, see "Spanning Tree Protocol (STP)" in chapter 9, "Configuring

 

Advanced Features", in the Management and Configuration Guide for your Series 2500 switch.

uplink port (upstream port)

wiring closet switch

A switch port linked to a port on another switch that is sequentially closer to the STP root device. For example, ports "A" and "B" in figure 67 on page 149 are uplink ports.

Another term for an "edge" or "leaf" switch.

149