Network+ - Lesson 8: Network Topologies

When ethernet traffic that is recirculated and amplified by loops in a switching topology, causing network slowdowns and crashing switches is called?

A Broadcast storm.

Describe a Hybrid Topology.

A network that uses a combination of physical or logical topologies. In practice most networks use hybrid topologies. For example, modern types of Ethernet are physically wired as stars but logically operate as buses.

What types of devices are connected in a PAN?

A personal area network (PAN) links devices such as laptops and smartphones and provides connectivity with peripheral devices (printers, input devices, headsets, and so on) plus wearable technology, such as fitness trackers and smart watches.

Describe a Bus Topology.

A shared access media where all nodes attach directly to a single cable segment. A bus network does allow cables to be connected using a device called a repeater. Two lengths of cable joined by a repeater is considered one length of cable for the purpose of the bus topology.

Describe a Mesh Topology.

A topology often used in WANs where each device has (in theory) a point-to-point connection with every other device (fully connected); in practice, only the more important devices are directly interconnected (partial mesh).

What is a trunk port?

A trunk port is a port on a switch configured to carry all 802.1q traffic, regardless of VLAN number, between the same VLAN's on multiple switches.

Define the 802.1q ethernet standard.

A trunking protocol that enables switches to exchange data about VLAN configurations. The 802.1Q protocol is often used to tag frames destined for different VLANs across trunk links using the VLAN ID number.

At which layer of the OSI model do VLANs establish network segments?

At the data link layer or layer 2.

A scope defining a network with direct connections between two or more buildings within the same overall area is called what?

Campus Area Network (CAN)

What are the three parts of Cisco's Three-Tiered Network Hierarchy?

Core Distribution Access

Facility dedicated to the provisioning of reliable power, environmental controls, and network fabric to server computers is called what?

Datacenter

True or False. Traffic from separate VLAN's can communicate directly with each other.

False, all traffic between separate VLAN's must be routed through a router.

Described the Core Tier.

Highest tier in a hierarchical network topology providing interconnections between blocks (Routers and L3 Switches).

Describe a Ring Topology.

In a ring topology, all of the computers are connected in a circle. The ring comprises a series of point-to-point links between each device. Signals pass from device to device in a single direction with the signal regenerated at each device.

Describe a Star Topology.

In a star network, each node is connected to a central point, typically a switch or a router. The central point mediates communications between the attached nodes. When a device such as a hub is used, the hub receives signals from a node and repeats the signal to all other connected nodes. Therefore the bandwidth is still shared between all nodes. When a device such as a switch is used, point-to-point links are established between each node as required. The circuit established between the two nodes can use the full bandwidth capacity of the network media.

Describe the Distribution Tier.

Intermediate tier in a hierarchical network topology providing interconnections between the access layer and the core (Access Switches)

Describe the Access Tier.

Lowest tier in a hierarchical network topology acting as the attachment point for end systems (End points/Hosts).

What network infrastructure implementation links multiple buildings within the same city?

Metropolitan area network (MAN).

What term is used to describe a topology in which two nodes share a single link?

Point-to-point.

Protocol that prevents layer 2 network loops by dynamically blocking switch ports as needed. Will define ports on switches as either a Root Port, Designated Port or Blocking Port.

Spanning Tree Protocol.

Spanning tree has been deployed without the administrator setting a priority value. Which of the following switches will be selected as the root? Switch A with base MAC f062.81ff.0001 and a 10 Gbps uplink Switch B with base MAC f062.81ff.0002 and a 40 Gbps uplink Switch C with base MAC f062.81ff.0003 and a 40 Gbps uplink

Switch A. The switch with the lowest value MAC address is selected if priority values are equal.

What type of frames are carried over tagged ports?

Tagged ports typically operate as trunks to carry frames between VLANs on different switches. Frames are transported over the trunk link with an 802.1Q header to indicate the VLAN ID.

You need operations to continue if one link fails. How many links does it take to connect three sites?

The number of links is n(n-1)/2, so with three sites, the sum is 3*2/2, which works out to three.

Which two topologies are used in the three-tier hierarchical model?

This is a hybrid topology with mesh and star elements.

True or False. A point-to-point topology is one where two nodes have a dedicated connection to one another.

True.

True or False. Normally, the network would be designed with a 1:1 mapping between VLANs and subnets.

True.

True or False. On modern networks, hybrid topologies are often used to implement redundancy and fault tolerance or to connect sites in WANs.

True.

True or false? A VLAN is a single broadcast domain.

True.

What is the ID number of the default or native VLAN?

VLAN 1

What is a VLAN?

VLAN is short for Virtual Area Network, it is any broadcast domain or subnet that is segregated using a defined section of switch ports. This allows for better network segmentation which helps manage and improve performance of a internetwork.

True or false? A broadcast storm can only be resolved by investing interface configurations.

False. A broadcast storm could be caused by a physical layer issue, such as improper cabling.

In what STP-configured state(s) are all ports when a network running STP is converged?

Forwarding or blocking.

Which values can be used to assign a port to a specific VLAN?

From 2 to 4,094. The all zeros and all ones (0 and 4,095) are reserved and VLAN ID 1 is the default for all unconfigured ports.