Juniper Networks EX2500 - Manual (Page 57)

Fast Uplink Convergence „ 43
Chapter 3: Spanning Tree Protocol
Add server ports 1 and 2 to VLAN 1. Add uplink ports 19 and port 20 to
VLAN 1.
ex2500(config)# vlan 1
ex2500(config-vlan)# enable
ex2500(config-vlan)# member 1
ex2500(config-vlan)# member 2
ex2500(config-vlan)# member 19
ex2500(config-vlan)# member 20
ex2500(config-vlan)# stg 1
ex2500(config-vlan)# exit
2. Configure Multiple Spanning Tree Protocol.
Configure the MSTP region name and version, and set the spanning tree mode
to
mst .
ex2500(config)# spanning-tree mstp name MyRegion
ex2500(config)# spanning-tree mode mst
ex2500(config)# spanning-tree mstp version 100
3. Configure port membership and define the Spanning Tree Groups (STGs) for
VLAN 2.
Add server ports 3, 4, and 5 to VLAN 2. Add uplink ports 19 and 20 to VLAN 2.
Assign VLAN 2 to Spanning Tree Group 2.
ex2500(config)# vlan 2
ex2500(config-vlan)# enable
ex2500(config-vlan)# member 3
ex2500(config-vlan)# member 4
ex2500(config-vlan)# member 5
ex2500(config-vlan)# member 19
ex2500(config-vlan)# member 20
ex2500(config-vlan)# stg 2
ex2500(config-vlan)# exit
Fast Uplink Convergence
Fast Uplink Convergence enables the EX2500 switch to recover quickly from the
failure of the primary link or trunk group in a Layer 2 network using Spanning Tree
Protocol. Normal recovery can take as long as 50 seconds, while the backup link
transitions from Blocking to Listening to Learning and then Forwarding states. With
Fast Uplink Convergence enabled, the EX2500 switch immediately places the
secondary path into Forwarding state, and sends multicasts of addresses in the
forwarding database (FDB) and ARP table over the secondary link so that upstream
switches can learn the new path.
NOTE: Each Spanning Tree Group (STG) is enabled by default.
NOTE: In order for Fast Uplink Convergence to be functional, the switch must be
running in PVRST+ mode and must be linked to switches running STP or PVST.