Is VLAN 1 the root bridge?

In Figure 3-39, S1 has been assigned as the primary root bridge, using the spanning-tree vlan 1 root primary command, and S2 has been configured as the secondary root bridge, using the spanning-tree vlan 1 root secondary command.

What is a root bridge and why do you need one?

If a link that was previously forwarding fails STP automatically enables one of redundant blocked links as the new active path. A Root Bridge is a reference point for all switches in a spanning-tree topology.

Which switch is the root?

The switch with the highest switch priority (the lowest numerical priority value) is elected as the root switch. If all of the switches are configured with the default priority (32768) for a VLAN with ID 1 (that is, a bridge priority of 32769), then the switch with the lowest MAC address becomes the root switch.

What happens when root bridge fails?

But if the root bridge goes down, or if the failure means that some switches no longer have a path to the root bridge, this constitutes a major topology change. A new root bridge needs to be selected. The entire network will freeze during this time and no packets can be forwarded.

Which switch would STP choose to become the root bridge in the selection process?

All switches exchange BPDU in order to elect root bridge. The switch with the lowest Bridge I’d will become the root bridge. Bridge I’d – It is a 8-byte field which is a combination of bridge priority (2 bytes) and Base Mac address (6 bytes) of a device.

Which switch would STP choose?

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 prevents a switch from becoming the root bridge?

Root Guard feature can be enabled on switch ports that is connected to other switches that should never become a Root Bridge. For example, a port on the distribution layer switch which is connected to an access layer switch can be Root Guard enabled, because the access layer switch should never become the Root Bridge.

What is STP loop guard?

The STP loop guard feature provides additional protection against Layer 2 forwarding loops (STP loops). An STP loop is created when an STP blocking port in a redundant topology erroneously transitions to the forwarding state. The designated port transmits BPDUs, and the non-designated port receives BPDUs.

What is the default bridge priority?

Every Bridge (Switch) Participating in a Spanning Tree Protocol network is assigned with a numerical value called Bridge Priority (Switch Priority) Value. By default, all Cisco Switches has a Bridge Priority (Switch Priority) value of 32,768.

What is root port STP?

The Root Port is the port on the Bridge (Switch) with the least Spanning Tree Path Cost from the switch to the Root Bridge. A Designated Port is the port on a Local Area Network (LAN) segment with the least Spanning Tree Path Cost to the Root Bridge (Root Switch). • There can be ONLY one Root Port on a Bridge (Switch).

How does a switch prevent loops?

In respect to this, how does a switch prevent loops? Because the “best ports” are put into forwarding state and the other ports are put into blocking state, there are no loops in the network. When a new switch is introduced to the network, the algorithm and port states are recalculated to prevent a new loop.

Which switch is the root bridge quizlet?

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.

How often does a switch send a Bpdu?

every two seconds

How is root bridge elected if all priorities are equal?

Since the BID starts with the Bridge Priority field, essentially, the switch with the lowest Bridge Priority field becomes the Root Bridge. If there is a tie between two switches having the same priority value, then the switch with the lowest MAC address becomes the Root Bridge.

What port type is used to interconnect switches in a switch stack?

StackWise ports

What is a Layer 2 loop?

In nutshell, a layer 2 switching loop creates three major problems; broadcast storm, duplicate frames, and unstable CAM table. If a loop exists, a single looped frame is sufficient to decrease the performance of the entire network by consuming the bandwidth and CPU power of the affected devices.

What are two advantages of EtherChannel?

What are two advantages of EtherChannel? (Choose two.)

Spanning Tree Protocol views the physical links in an EtherChannel as one logical connection.
Load balancing occurs between links configured as different EtherChannels.
Configuring the EtherChannel interface provides consistency in the configuration of the physical links.

Which port role is assigned to the switch?

Question: Which port role is assigned to the switch port that has the lowest cost to reach the root bridge? Explanation: The root port on a switch is the port with the lowest cost to reach the root bridge.

What are three characteristics of VTP?

What are three characteristics of VTP? (Choose three.)

In the default VTP mode, VLANs can be created and modified on a switch.
Switches in VTP server mode store VLANs in the vlan.
VTP-enabled switches exchange three types of advertisements: summary routes, subnet advertisements, and advertisement requests from transparent bridges.

What are two requirements to be able to configure an EtherChannel between two switches?

What are two requirements to be able to configure an EtherChannel between two switches? (Choose two.)

All the interfaces need to work at the same speed.
All interfaces need to be assigned to different VLANs.
Different allowed ranges of VLANs must exist on each end.

What are two methods for switching data between ports on a switch choose two?

There are 2 methods that all switch use for forwarding the frames (switching data) between the network ports:

Store and forward switching.
Cut-through switching.

What are the three types of switching?

There are three types of message switching techniques used:

Circuit Switching.
Message Switching.
Packet Switching.

What are the three types of switching techniques?

There are three types of switching methods: the store-and-forward method, the fragment-free method, and the cut-through method. In all three methods, the first and second phases are the same.

What are the three switching techniques?

There are 3 common switching techniques:

Circuit Switching.
Packet Switching.
Message Switching.