Dell EMC SmartFabric OS10 User Guide Release 10.5.0

Rapid-PVST determines the root bridge by the VLAN bridge priority. 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, from 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