Lesson 8: Explaining Network Topologies and Types Flashcards
Define a client-server network
A network where its nodes are made up of PCs, laptops, and servers
Define a peer-to-peer network
A network where an end system acts as both client and server, typically in a residential network
Define a star topology
Endpoint nodes are connected to a central forwarding node, such as a hub, switch, or router. The central node mediates communications between the endpoints
Define a mesh topology
Each device has (in theory) a point-to-point connection with every other device to create redundant routes
What is the equation to determine how many links are needed in a mesh network
Let n represent the number of nodes planned to be in the network: n (n-1)/2
Define a ring topology
A topology where each node has a point to point connection with each of its neighbors in the logical ring, each node will receive a transmission and continue to forward it until the transmission has reached its destination
Define a bus topology
A logical bus topology is one in which nodes are attached to the single cable and receive the data transmitted all at the same time, regardless of the physical wiring layout of the network
Define a Personal Area Network
The concept of IOT such as phones, laptops, printers, smart watches to connect to each other
Define the three tiered network hierarchy
Paradigm to simplify network design by separating switch and router functionality with a separate role and topology
What three tiers make up a three-tiered network hierarchy?
- Access/Edge layer
- Distribution/Aggregation layer
- Core layer
Define the Access layer
Bottom tier of the hierarchy that allows end-user devices to connect to the network through wired/wireless access and LAN switches
Define the Distribution/Aggregation layer
Intermediate tier that provides fault-tolerant interconnections between the access layer and the core layer using layer 3 capable switches with 10GB for switching and 40GB ports for routing
What technology does a layer 3 switch use?
Application Specific Integrated Circuit (ASIC)
Define the Core layer
Highest tier in three-tiered network hierarchy that uses routers and layer 3 switches configured in a mesh topology to provide redundant paths for data to flow around the access and distribution layers
What layer 2 protocol is used to prevent network loops?
Spanning tree protocol (STP)
Define a spanning tree protocol hierarchy
The root bridge is the switch at the top of the hierarchy and is selected based on the lowest ID and is connected to the remaining bridges
How do switches in a spanning tree hierarchy communicate?
Using data packaged as bridge protocol data unit (BPDU) in multicast frames
Once configured, how does data flow between switches using spanning tree protocol (STP)?
The root bridge has two designated ports (DP) connected to lower tiered bridges. The lower tiered bridges have root ports (RP) connected back to the designated ports on the root bridge. The lower tiered bridges also have a connection directly to one another. One of the bridges in the lower tier must have a blocked port (BP) to prevent a loop
How is spanning tree protocol configured on the switch?
If the switch supports STP it will operate by default, but and administrator should set priority value to define the root switch
List the states a port can be in when the switch is using spanning tree protocol
- Blocking - can’t forward or learn MACs
- Listening - can’t forward or learn MACs but listens for BPDUs to detect loops
- Learning - only listens for MACs to build MAC table and hierarchy
- Forwarding - Preforms forwarding and learning
- Disabled
Described what it takes for spanning tree protocol network to be converged
All ports on all the switches are in forwarding or blocking states
What is a switching flood
An issue where layer 2 broadcast messages (ARP, DHCP) circulate the network perpetually, which causes the switches to clear MAC address tables and start flooding unicast traffic
Left unmanaged, what are the consequences of a switching flood?
A broadcast storm will occur, causing network latency and crashing switches
Which two network models/topologies are used in a three-tier hierarchical model?
Core layer is mesh as well as the links between the core and distribution layer while the access layer uses a star topology to connect end systems
What is the link used to connect two switches to each other?
Backbone link/Trunk
How do trunked switches determine where to forward frames?
The VLAN ID (VID) of each frame is stored in the 802.1Q tag in an ethernet frame
What is an untagged port?
Designation configured for ports that are connected to an end system
What is a tagged/trunked port?
Designation configured for ports that are connected to another switch operating as a trunk
What are the two ways a switch processes a VLAN tag
- If a frame is addressed to a port in the same VLAN, no tag is added to the frame
- If the frame needs to be transported over the trunk link, the switch adds the relevant 802.1Q tag to identify the VLAN
