2b. Layer 2 Switching (cont.)

To process and forward a frame that has been received also requires a certain percentage of the switch's _________ ______________ _________

Central Processing Unit (CPU)

Broadcasts frames are a big concern on a network without proper __________ _____________

Loop Avoidance.

A state for a switchport where STP has determined the possibility of a loop exists should the switchport be allowed to forward frames

Blocking

When a root bridge is selected, All redundant links will be placed in a ________ _________ for loop prevention.

Blocking state.

The election of the root bridge is accomplished via ________ __________ ______ __________ that are sent out by the switches

Bridge Protocol Data Units (BPDUs)

___________ frames that have a destination address of FFFF.FFFF.FFFF, are sent out by individual nodes on a computer network when using a variety of different protocols.

Broadcast

A _____________ _________ has the possibly to bring down an entire base's network if proper loop avoidance is not diligently applied beforehand.

Broadcast Storm

Caused when the amount of traffic generated or caused by loop can max out the bandwidth of neighboring links and CPU for neighboring devices.

Broadcast Storm

In a broadcast storm, loops and legitimate traffic will cause a switch to eventually reach a breaking point where it is unable to process frames entirely and quickly maxes out its _______ _______________

CPU Utilization

All ports that are permitted to forward on the root bridge are referred to as ___________ ___________.

Designated Ports.

A state for a switchport where it is administratively shutdown.

Disabled

If two switches with two or more paths between them were unaware of where to send a frame, they could potentially do what?

Forward the frame between themselves infinitely.

A state for a switchport after the initial listening and learning states have occurred.

Forwarding

In the ___________ state, if the STP topology should change, the port can still transition into a blocking state if required.

Forwarding

In the ___________ state, the switchport will continue to process BPDUs to make determinations on the STP topology that it is connected to.

Forwarding

In the _____________ state, a switchport is in normal operation and is both receiving and forwarding frames that contain data from nodes on the computer network.

Forwarding

When the root bridge is selected, all participating switches in the STP topology will choose their best link to the switch selected as the root bridge and place it in a ___________ _________.

Forwarding state.

STP will allow traffic to flow through the switchports it designates to be in a ___________ state while disallowing traffic on switchports it designates to be in a _________ state.

Forwarding, Blocking

A state for a switchport after the initial listening state has occurred.

Learning

A state for a switchport where it will process received BPDUs to decide on the STP topology that it is connected to.

Listening

This state will NOT populate the MAC address table of the switch and will NOT forward frames that contain data from nodes on the network.

Listening state

A ______ on a computer network happens when there is more than one link between two pieces of network equipment that causes repetition of the frames being transmitted between them to literally loop between them infinitely

Loop

On large computer networks, the possibility to _______ large numbers of frames exists.

Loop

STP will designate a switch in the topology as the __________ __________.

Root Bridge.

Ports that are permitted to forward on non-root bridge switches are referred to as _________ ____________ (because they point towards the root bridge)

Root Ports

Being aware of these port states, and where they are helps with troubleshooting, figuring out how to prioritize bandwidth, and practicing diligent loop avoidance.

Spanning-Tree Port States

____________-___________ _______________ will assess multiple paths that exist between a switch and another switch and prioritize one switchport involved in that communication path over the other.

Spanning-Tree Protocol

__________-__________ ___________ allows for multiple paths to exist between pieces of network equipment on a computer network without the threat of a potential broadcast storm occurring

Spanning-Tree Protocol (STP)

In ____________-___________ _______________, the protocol will assign various roles to the active switchports involved in forwarding traffic between the participating STP configured switches on a computer network.

Spanning-Tree Topology

STP is configured on switches and the protocol creates its own ____________ on top of the physical topology on the live computer network.

Topology

BPDUs are frames which are sent out by switches that contain relevant information to STP and are sent out every _______ seconds by default.

Two

A broadcast storm is an example of an ___________ ____________

availability threat

To prevent a potential broadcast storm from occurring on a computer network, frames containing data from nodes on the network are neither sent or received by the ________ switchport.

blocking

Redundant ports which are not designated as root ports in a STP topology will receive a __________ ___________ role on one side of the connection, while the other side of the link will go into a ___________ state.

designated port, blocking

A switchport assigned to a blocking state will transition to a _____________ state if STP has determined a change in the _____________ requires it.

forwarding, topology

This state is unable to forward frames containing data from nodes on the network, however, it will begin to populate the MAC address table with the source MAC address of any frames received on the interface it is assigned to

learning state