Determining the root bridge?

Demiurge

What switch command will show you which switch is the root bridge?

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Netstudent

show spanning-tree under priviledged mode.

nice343

show spanning tree root

mattsthe2

nice343 wrote:
show spanning tree root

I prefer Netstudents, If you need a quick and clear answer.

You'll see something like this

This bridge is the root

you'll also be able to compare the Bridge ID (current switch) and the Root ID. These may be the same. I.E its the root.

nice343

mattsthe2 wrote:
nice343 wrote:
show spanning tree root
I prefer Netstudents, If you need a quick and clear answer.

You'll see something like this
This bridge is the root
you'll also be able to compare the Bridge ID (current switch) and the Root ID. These may be the same. I.E its the root.

??????????

Looks like you never used this command before making that statement.

switch#sh spanning-tree root
VLAN1
  Root ID    Priority    32768
             Address     cc00.0c5c.0000
             This bridge is the root
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
VLAN20
  Root ID    Priority    32768
             Address     cc00.0c5c.0001
             This bridge is the root
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
VLAN30
  Root ID    Priority    32768
             Address     cc00.0c5c.0002
             This bridge is the root
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

networker050184

Show spanning-tree root would be the best to just find the root, but it doesn't give you all the extra info you get from the show spanning-tree command.

mattsthe2

Hmmmm.

I was going off of my test switch

Switch#sh spanning-tree root

                                        Root    Hello Max Fwd
Vlan                   Root ID          Cost    Time  Age Dly  Root Port
---------------- -------------------- --------- ----- --- ---  ------------
VLAN0001          8193 0018.191f.e080         6    2   20  15  Po3
VLAN0010          8202 0018.191f.e080         6    2   20  15  Po3
VLAN0020          8212 0018.191f.e080         6    2   20  15  Po3
VLAN0030          8222 0018.191f.e080         6    2   20  15  Po3
VLAN0040          8232 0018.191f.e080         6    2   20  15  Po3
VLAN0050          8242 0018.191f.e080         6    2   20  15  Po3
VLAN0070          8262 0018.191f.e080         6    2   20  15  Po3

Plazma

Looks like it is the root bridge for all the vlans listed

mattsthe2

Plazma wrote:

Looks like it is the root bridge for all the vlans listed

right but a different output from yours.

Maybe different IOS or new switch... This is a 3560.