Users Guide

Table Of Contents
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
-----------------------------------------------------------------------------------
ethernet1/1/1 128.260 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.260
ethernet1/1/2 128.264 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.264
ethernet1/1/3 128.268 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.268
ethernet1/1/4 128.272 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.272
ethernet1/1/5 128.276 128 500 FWD 0 32768 3417.4455.667f 128.146
ethernet1/1/6 128.280 128 500 BLK 0 32768 3417.4455.667f 128.150
ethernet1/1/7 128.284 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.284
ethernet1/1/8 128.288 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.288
ethernet1/1/9 128.292 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.292
ethernet1/1/10 128.296 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.296
ethernet1/1/11 128.300 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.300
ethernet1/1/12 128.304 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.304
ethernet1/1/13 128.308 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.308
ethernet1/1/14 128.312 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.312
ethernet1/1/15 128.316 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.316
ethernet1/1/16 128.320 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.320
ethernet1/1/17 128.324 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.324
ethernet1/1/18 128.328 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.328
ethernet1/1/19 128.332 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.332
ethernet1/1/20 128.336 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.336
ethernet1/1/21 128.340 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.340
ethernet1/1/22 128.344 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.344
ethernet1/1/23 128.348 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.348
ethernet1/1/24 128.352 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.352
ethernet1/1/25 128.356 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.356
ethernet1/1/26 128.360 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.360
ethernet1/1/27 128.364 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.364
ethernet1/1/28 128.368 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.368
ethernet1/1/29 128.372 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.372
ethernet1/1/30 128.376 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.376
ethernet1/1/31 128.380 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.380
ethernet1/1/32 128.384 128 200000000 BLK 0 32768 90b1.1cf4.a523 128.384
Interface
Name Role PortID Prio Cost Sts Cost Link-type Edge
--------------------------------------------------------------------------
ethernet1/1/1 Disb 128.260 128 200000000 BLK 0 AUTO No
ethernet1/1/2 Disb 128.264 128 200000000 BLK 0 AUTO No
ethernet1/1/3 Disb 128.268 128 200000000 BLK 0 AUTO No
ethernet1/1/4 Disb 128.272 128 200000000 BLK 0 AUTO No
ethernet1/1/5 Root 128.276 128 500 FWD 0 AUTO No
ethernet1/1/6 Altr 128.280 128 500 BLK 0 AUTO No
ethernet1/1/7 Disb 128.284 128 200000000 BLK 0 AUTO No
ethernet1/1/8 Disb 128.288 128 200000000 BLK 0 AUTO No
ethernet1/1/9 Disb 128.292 128 200000000 BLK 0 AUTO No
ethernet1/1/10 Disb 128.296 128 200000000 BLK
Root selection
MSTP determines the root bridge according to the lowest bridge ID. To increase the probability of a bridge to be selected as a root bridge,
assign a lower bridge priority to that bridge.
Assign a bridge priority number to a specic instance in CONFIGURATION mode, from 0 to 61440 in increments of 4096, default 32768.
spanning-tree mst instance-number priority priority
Assign root bridge priority
OS10(config)# spanning-tree mst 0 priority 32768
Verify root bridge priority
OS10# show spanning-tree active
Spanning tree enabled protocol msti with force-version mst
MSTI 0 VLANs mapped 1,31-4093
Executing IEEE compatible Spanning Tree Protocol
Root ID Priority 32768, Address 3417.4455.667f
Layer 2
425