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What are the four step decision that STP used to elect a root bridge?
Designated port – The port which sends the best BPDU i.e ports on the root bridge will be in a forwarding state. Root port – The port which receives the best BPDU on a non-root bridge. Criteria for selecting root port: Lowest path cost to reach the root bridge. Lowest sender bridge ID.
What is the role of root bridge in Spanning Tree?
The root bridge serves as a reference point for all spanning-tree calculations to determine which redundant paths to block. An election process determines which switch becomes the root bridge.
How does STP select the root port on Nonroot bridge?
STP Root Port Selection
- Lowest bridge ID (Priority:MAC Address) switch becomes the Root-Bridge.
- Each non-root bridge should have ONE root port (RP) which is the port having lowest path-cost to Root Bridge.
- All ports in Root Bridge become Designated Ports (DP)
- Each segment should have one Designated Port (DP)
What determines which switch becomes the STP root bridge for a given vlan?
The switch with the lowest BID becomes the Root Bridge. Since the BID starts with the Bridge Priority field, essentially, the switch with the lowest Bridge Priority field becomes the Root Bridge.
Which of the following would STP choose to become the root bridge in the selection process?
Root switches are elected on the lowest priority . if two switches have the same priority,then the one with the lowest MAC address is chosen. out of the four choices here, A and B have the lowest priority,and A has the lowest MAC address, so A is chosen.
What is STP protocol and how it works?
What is STP and how does it work? Spanning Tree Protocol (STP) is a Layer 2 network protocol used to prevent looping within a network topology. STP was created to avoid the problems that arise when computers exchange data on a local area network (LAN) that contains redundant paths.
Which switch should be the root bridge?
Every switch taking part in spanning tree has a bridge priority. The switch with the lowest priority becomes the root bridge. If there’s a tie, then the switch with the lowest bridge ID number wins. The ID number is typically derived from a MAC address on the switch.
How do I change root bridge priority?
If an alternate root bridge is desired, use the spanning-tree vlan vlan-id root secondary global configuration mode command. This command sets the priority for the switch to the predefined value 28,672. This ensures that the alternate switch becomes the root bridge if the primary root bridge fails.
What is the best method of ensuring that your preferred switch is the root bridge?
The switch with the lowest priority, which means lowest BID, becomes the root bridge (the lower the priority value, the higher the priority). For example, to ensure that a specific switch is always the root bridge, you set the priority to a lower value than the rest of the switches on the network.
Which switch would STP choose to become?
STP Root Bridge / Root Switch Selection This is possible because each switch can be configured with a lower bridge priority, which ensures it becomes the root switch.
What attributes are used to select a root bridge?
What attributes are used to elect a root bridge? The switch with the lowest bridge priority is elected as the root bridge. In the event of a tie, the bridge MAC address is used to elect a root bridge.
What is the use of spanning-tree algorithm for bridge routing?
The intent of the Distributed Spanning Tree Algorithm is to identify the node (i.e. bridge) with smallest id, the root-bridge of the network; Then for every other node, to identify the port, root-port, through which goes the shortest path to the root-bridge.
Where should root bridge be?
must be placed in a central part of the network, to provide the best possible data path. Root Bridge (Root Switch) must be placed near to Network Servers and other important devices which are the sources of high network traffic to ensure that the topology of the network is optimized to the traffic flows of the network.
Which option identifies the STP bridge priority range?
The default priority is 32768, and additional roots are set below this number. STP increments priority by 4096, so the next priority is 4096 below 32768. The lower the number, the higher the priority.
How do I set priority in STP?
Another method for configuring the bridge priority value is by using the spanning-tree vlan vlan-id priority value global configuration mode command. This command gives more granular control over the bridge priority value. The priority value is configured in increments of 4096 between 0 and 61,440.
How does Spanning Tree determine priority?
Ports included in the spanning tree are selected. The shortest distance to the root switch is calculated for each switch based on the path cost. For each VLAN, the switch with the highest bridge priority (the lowest numerical priority value) is elected as the root switch.
What is spanning tree?
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Is spanning tree Cisco priority?
Spanning Tree Priority: Root Primary and Root Secondary. Spanning Tree Protocol is a Layer 2 loop prevention mechanism that will block one port on the network switch if it detects a loop of broadcast messages within its architecture. By default, spanning trees are enabled on most interconnected Cisco switches.
How to enable or disable Spanning Tree Protocol (STP)?
– Log in to the Insight Cloud Portal. – Select the network location for which you want to enable or disable STP. – Select Wired > Settings > Spanning Tree. – Under Spanning Tree Mode, select Disable, STP, or RSTP. – Tap Save. Your changes are saved.
What is a spanning tree in a network?
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