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
2.Configure Multiple Spanning Tree Protocol.
Configure the MSTP region name and version, and set the spanning tree mode to mst.
ex2500(config)#
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
NOTE: Each Spanning Tree Group (STG) is enabled by default.
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: 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.
Fast Uplink Convergence 41