what is Root ID in stp?

[sonia.j.aditya]

Hi All,

i need some help in understanding what is the difference between RootID and Bridge Id.I know bridge id is priority.mac add and that it elects the root bridge and determine which switch is gonna have is link blocked. but what is this root ID???

[Peter Paluch · Accepted solution]

Hi Sonia,

The Root ID is the Bridge ID of the root bridge - as simple as that. As you know, every bridge and switch has its own unique Bridge ID that consists of three fields:

• Configurable priority
• Instance number, usually the VLAN ID for which the STP runs
• MAC address of the switch

One switch will be elected the root switch based on the lowest overall Bridge ID, and this Bridge ID of the root switch is known colloquially as the Root ID.

Best regards,

Peter

[Joseph W. Doherty]

Just to add to Peter's information, the root bridge is often manually configured to be such.

[inj3ctX]

thank you i was helped too