Chapter 6 Multiple instance spanning tree operation...........................103
Overview of MSTP...................................................................................................................................... 103
MSTP structure................................................................................................................................ 105
How MSTP operates........................................................................................................................105
802.1s Multiple Spanning Tree Protocol (MSTP).....................................................................................105
MST regions..................................................................................................................................... 106
How separate instances aect MSTP........................................................................................... 107
Regions, legacy STP and RSTP switches, and the Common Spanning Tree (CST)................... 108
MSTP operation with 802.1Q VLANs.............................................................................................108
MSTP compatibility with RSTP or STP...................................................................................................... 109
Preconguring an MSTP regional topology.............................................................................................109
Preconguring VLANs in an MST instance................................................................................... 110
Conguring MSTP instances with the VLAN range option (Example).......................................111
Saving the current conguration before a software upgrade................................................... 112
Types of Multiple Spanning Tree Instances.............................................................................................113
Planning an MSTP application.................................................................................................................. 113
Conguring MSTP at a glance................................................................................................................... 114
Conguring MSTP operation mode and global settings........................................................................116
Selecting MSTP as the spanning tree mode................................................................................ 116
Clearing spanning tree debug counters.......................................................................................116
Resetting the conguration name of the MST region in which a switch resides.................... 116
Designating the revision number of the MST region for a switch.............................................116
Setting the spanning tree compatibility mode............................................................................ 117
Setting the time interval between listening, learning, and forwarding states.........................117
Setting spanning tree to operate in 802.1D legacy mode..........................................................118
Setting spanning tree to operate with 802.1D legacy path cost values................................... 118
Specifying the time interval between BPDU transmissions.......................................................118
Setting the hop limit for BPDUs.................................................................................................... 118
Setting the maximum age of received STP information............................................................ 119
Manipulating the pending MSTP conguration.......................................................................... 119
Setting the bridge priority for a region and determining the root switch............................... 119
Enabling SNMP traps...................................................................................................................... 120
Conguring MSTP per-port parameters..................................................................................................120
Enabling immediate transition to forwarding on end nodes.................................................... 120
Identifying edge ports automatically............................................................................................121
Specifying the interval between BPDU transmissions............................................................... 121
Forcing a port to send RST/MST BPDUs....................................................................................... 122
Determining which ports are forwarding ports by assigning port cost................................... 122
Informing the switch of the device type to which a port connects ..........................................122
Determining which port to use for forwarding........................................................................... 122
Denying a port the role of root port............................................................................................. 123
Denying a port propagation change information....................................................................... 123
Congure MST instance ports parameters............................................................................................. 124
Create a new instance or map VLAN(s) to an existing one................................................................... 124
Enable event logging..................................................................................................................................124
Deleting an instance.................................................................................................................................. 124
Congure an existent instance................................................................................................................. 124
MSTP Cong example.....................................................................................................................125
Downgrading to lower version build........................................................................................................125
Operating notes for the VLAN conguration enhancement................................................................. 125
Conguring MST instance parameters.................................................................................................... 126
Setting the bridge priority for an instance.............................................................................................. 126
Assigning a port cost for an MST instance.............................................................................................. 127
Setting the priority for a port in a specied MST instance....................................................................127
6Aruba 2530 Advanced Trac Management Guide for
ArubaOS-Switch 16.09
