CNT 150: Chapter 5: Purpose of STP

STP prevents loops from occurring by doing what?

Configuring a loop-free path through the network using strategically placed blocking-state port.

Bridges are a old nickname for what layer 2 device?

Switch

What causes a broadcast storms?

Can be caused by hardware problem such as faulty NIC or from a Layer 2 loop in the network.

Without STP enabled layer 2 loops form, from what type of traffice?

Unknow Unicast Broadcast (can be an arp request) Multicast DHCP broadcast

What does least cost path mean?

Best Path

STP ensures that there is only one logical path between all destinations on the network by intentionally doing what?

Blocking redundant paths

STP is based on an algorithm invited by who?

Radia Perlman

What device is elected by the Spanning Tree Algorithm? All other switches determine a single least-cost path to this device. root bridge dedicated bride default gateway core switch

Root Bridge

Which statement describes STP? STP is a Layer 2 routing protocol. STP is a Layer 3 routing protocol for Ethernet LANs. STP is a Layer 2 loop prevention protocol for Ethernet LANs. STP is a Layer 3 loop prevention protocol for IP networks.

STP is a Layer 2 loop prevention protocol for Ethernet LANs

What does STA stand for?

Spanning Tree Algorithm

What does STP do?

Is a loop-prevention network protocol that allows for redundancy while creating a loo-free layer 2 topology. IEEE 802.1S is the original IEEE MAC Bridging standard for STP

What is a broadcast storm?

Is an abnormally high number of broadcasts overwhelming the network during a specific amount of time.

When do STP recalculations occur?

Link fails or a switch goes down New switch is added

A layer 2 loop can cause what kind of issues on layer 2 and end-devices?

MAC address table instability Link saturation HIGH CPU Utilization

What are the do major functions of the STP protocol?

Redundancy Elimination of Layer 2 Loops

What does STP stand for ?

Spanning Tree Protocol

What is a root bridge?

The root bridge is the switch that all traffic passes through. The root bridge originates configuration BPDUs. The root bridge determines the timers.

What was STP created for?

To stop layer 2 loops

The switches running STP are able to compensate for failures by dynamically doing what?

Unblocking the previously blocked port and permitting traffic to traverse the alternate paths.

Without STP on a the Ethernet LAN, which three types of frames could cause a catastrophic loop in the network? (Choose Three) Unicast Unknow Unicast Broadcast Multicast

Unknow Unicast Broadcast Multicast

When does a layer 2 loop occur?

When multiple paths exist between two devices on an Ethernet network, and there is no spanning tree implementation on the switches.