OS10 Enterprise Edition User Guide Release 10.4.1.0

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Select root bridge

RPVST+ determines the root bridge. Assign one bridge a lower priority to increase the likelihood that it becomes the root bridge. The show spanning-tree brief command displays information about all ports regardless of the operational status.

  • Assign a number as the bridge priority or designate it as the root in CONFIGURATION mode (0 to 61440).
    spanning-tree {vlan 
                                           vlan-id priority 
                                           priority-value}
                                        
    • vlan-id — Enter a value between 1 to 4093.
    • priority priority-value — Enter the priority value in increments of 4096, default is 32768. The lower the number assigned, the more likely this bridge becomes the root bridge. The bridge priority the valid values are: 0, 4096, 8192, 12288, 16384, 20480, 24576, 28672, 32768, 36864, 40960, 45056, 49152, 53248, 57344, or 61440. All other values are rejected.

Configure root bridge

OS10(config)# spanning-tree vlan 1 priority 4096

View active configuration

OS10(config)# do show spanning-tree active
                                 Spanning tree enabled protocol rapid-pvst with force-version rstp
                                 VLAN 1
                                 Executing IEEE compatible Spanning Tree Protocol
                                 Root ID    Priority 4097, Address 90b1.1cf4.a523
                                 Root Bridge hello time 2, max age 20, forward delay 15
                                 Bridge ID    Priority 4097, Address 90b1.1cf4.a523
                                 We are the root of VLAN 1
                                 Configured hello time 2, max age 20, forward delay 15
                                 Interface                                               Designated
                                 Name            PortID   Prio Cost Sts  Cost Bridge ID     PortID
                                 ---------------------------------------------------------------------
                                 ethernet1/1/5   128.276  128  500  FWD  0    4097   90b1.1cf4.a523  128.276
                                 ethernet1/1/6   128.280  128  500  FWD  0    4097   90b1.1cf4.a523  128.280
                                 Interface
                                 Name            Role  PortID   Prio Cost Sts  Cost Link-type Edge
                                 --------------------------------------------------------------
                                 ethernet1/1/5   Desg  128.276  128  500  FWD  0    AUTO      No
                                 ethernet1/1/6   Desg  128.280  128  500  FWD  0    AUTO      No
                              

View brief configuration

OS10# show spanning-tree brief
                                 Spanning tree enabled protocol rapid-pvst with force-version rstp
                                 VLAN 1
                                 Executing IEEE compatible Spanning Tree Protocol
                                 Root ID    Priority 4097, Address 90b1.1cf4.a523
                                 Root Bridge hello time 2, max age 20, forward delay 15
                                 Bridge ID    Priority 4097, Address 90b1.1cf4.a523
                                 We are the root of VLAN 1
                                 Configured hello time 2, max age 20, forward delay 15
                                 Interface                                                    Designated
                                 Name             PortID   Prio  Cost      Sts   Cost  Bridge ID             PortID
                                 ---------------------------------------------------------------------------------
                                 ethernet1/1/1    128.260  128   200000000 FWD   0     32769  0000.0000.0000  128.260
                                 ethernet1/1/2    128.264  128   200000000 FWD   0     32769  0000.0000.0000  128.264
                                 ethernet1/1/3    128.268  128   200000000 FWD   0     32769  0000.0000.0000  128.268
                                 ethernet1/1/4    128.272  128   200000000 FWD   0     32769  0000.0000.0000  128.272
                                 ethernet1/1/5    128.276  128   500       FWD   0     4097   90b1.1cf4.a523  128.276
                                 ethernet1/1/6    128.280  128   500       FWD   0     4097   90b1.1cf4.a523  128.280
                                 ethernet1/1/7    128.284  128   200000000 FWD   0     32769  0000.0000.0000  128.284
                                 ethernet1/1/8    128.288  128   200000000 FWD   0     32769  0000.0000.0000  128.288
                                 ethernet1/1/9    128.292  128   200000000 FWD   0     32769  0000.0000.0000  128.292
                                 ethernet1/1/10   128.296  128   200000000 FWD   0     32769  0000.0000.0000  128.296
                                 ethernet1/1/11   128.300  128   200000000 FWD   0     32769  0000.0000.0000  128.300
                                 ethernet1/1/12   128.304  128   200000000 FWD   0     32769  0000.0000.0000  128.304
                                 ethernet1/1/13   128.308  128   200000000 FWD   0     32769  0000.0000.0000  128.308
                                 ethernet1/1/14   128.312  128   200000000 FWD   0     32769  0000.0000.0000  128.312
                                 ethernet1/1/15   128.316  128   200000000 FWD   0     32769  0000.0000.0000  128.316
                                 ethernet1/1/16   128.320  128   200000000 FWD   0     32769  0000.0000.0000  128.320
                                 ethernet1/1/17   128.324  128   200000000 FWD   0     32769  0000.0000.0000  128.324
                                 ethernet1/1/18   128.328  128   200000000 FWD   0     32769  0000.0000.0000  128.328
                                 ethernet1/1/19   128.332  128   200000000 FWD   0     32769  0000.0000.0000  128.332
                                 ethernet1/1/20   128.336  128   200000000 FWD   0     32769  0000.0000.0000  128.336
                                 ethernet1/1/21   128.340  128   200000000 FWD   0     32769  0000.0000.0000  128.340
                                 ethernet1/1/22   128.344  128   200000000 FWD   0     32769  0000.0000.0000  128.344
                                 ethernet1/1/23   128.348  128   200000000 FWD   0     32769  0000.0000.0000  128.348
                                 ethernet1/1/24   128.352  128   200000000 FWD   0     32769  0000.0000.0000  128.352
                                 ethernet1/1/25   128.356  128   200000000 FWD   0     32769  0000.0000.0000  128.356
                                 ethernet1/1/26   128.360  128   200000000 FWD   0     32769  0000.0000.0000  128.360
                                 ethernet1/1/27   128.364  128   200000000 FWD   0     32769  0000.0000.0000  128.364
                                 ethernet1/1/28   128.368  128   200000000 FWD   0     32769  0000.0000.0000  128.368
                                 ethernet1/1/29   128.372  128   200000000 FWD   0     32769  0000.0000.0000  128.372
                                 ethernet1/1/30   128.376  128   200000000 FWD   0     32769  0000.0000.0000  128.376
                                 ethernet1/1/31   128.380  128   200000000 FWD   0     32769  0000.0000.0000  128.380
                                 ethernet1/1/32   128.384  128   200000000 FWD   0     32769  0000.0000.0000  128.384
                                 Interface
                                 Name             Role   PortID   Prio  Cost      Sts   Cost Link-type Edge
                                 -----------------------------------------------------------------------
                                 ethernet1/1/1    Disb   128.260  128   200000000 FWD   0    AUTO      No
                                 ethernet1/1/2    Disb   128.264  128   200000000 FWD   0    AUTO      No
                                 ethernet1/1/3    Disb   128.268  128   200000000 FWD   0    AUTO      No
                                 ethernet1/1/4    Disb   128.272  128   200000000 FWD   0    AUTO      No
                                 ethernet1/1/5    Desg   128.276  128   500       FWD   0    AUTO      No
                                 ethernet1/1/6    Desg   128.280  128   500       FWD   0    AUTO      No
                                 ethernet1/1/7    Disb   128.284  128   200000000 FWD   0    AUTO      No
                                 ethernet1/1/8    Disb   128.288  128   200000000 FWD   0    AUTO      No
                                 ethernet1/1/9    Disb   128.292  128   200000000 FWD   0    AUTO      No
                                 ethernet1/1/10   Disb   128.296  128   200000000 FWD   0    AUTO      No
                                 ethernet1/1/11   Disb   128.300  128   200000000 FWD   0    AUTO      No
                              

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