Routing and Switching Flashcards
What is a collision domain
Collision domain: A network or segment where a group of nodes competes with each other for access to the media.
Definition of microsegregation
Microsegmentation: The process of dividing up a network by using switches so that only two nodes exist in each collision domain.
Definition of a broadcast domain
Broadcast domain: A network or segment where any node connected to the network can directly transmit to any other node in the area without a central routing device.
Give all characteristics of a collision domain
Collision domains Logical bus Hub and connected nodes Coax bus Switch port and connected node
Give all characteristics of a broadcast domain
Broadcast domains
Not affected by micro-segmentation
Single switch or group of connected switches
Routers define the boundaries
What is STP
A Layer 2 protocol is used to prevent switching loops in switches that support the protocol.
Why do loops occur in layer 2 within switches
Loops happen when there are redundant paths between switches.
Loops can cause broadcast storms when nodes send ARP frames to identify neighbors.
Characteristics of STP
Not all switches support STP! STP is relatively old and slow Replaced by RSTP and SPB protocols Rapid Spanning Tree Protocol Shortest Path Bridging Port states and BPDU
Port states and BPDUs
What happens when blocking occurs
User data is not sent or received.
BPDU data is received and used to determine if the port state should be changed.
Port states and BPDUs
What happens when listing occurs
BPDUs are processed by the switch.
Frames are not forwarded, and the switch does not update the MAC tables
Definition of Packet Switched Networks
A network where data is broken up into separate packets and each packet is separately routed without a dedicated connection between the endpoints.
Give all characteristics of a Packet Switched Network
Each packet finds its own route.
All packets contain routing and sequencing information.
Data is reassembled after all packets are received by the destination host.
Used when networks change often due to network congestion or changing link states.
Definition of Circuit Switching
A switching technique where one endpoint creates a single connection to the other endpoint.
Give all the characteristics of circuit switching
The circuit is the path.
Data flows through the circuit as long as the circuit is active.
When the data transfer is complete, the circuit is closed.
Definition of Distributed Switching
A switching technique where a centralized switch connects and manages switches that have been deployed remotely in a hierarchical configuration.
Characteristics of a Distributed Switching
On telephony networks, it’s called host-remote switching.
The central/host switch:
Connects remote switches to each other and to other networks.
Manages complex calls, whereas remote switches handle local calls.
Provide operation, administration, maintenance, provisioning, and billing.
Can be implemented on data networks and virtual networks, too.
Definition of Routing
The process of selecting the best route for moving a packet from its source to its destination on a network.
Characteristics for Routing
Routers use algorithms to generate and maintain information about network paths.
Metrics are used to determine the best route
When the best route is identified, packet switching gets the data to the destination.
Forwarding a packet from one router to another is called a hop.
What are the metrics for routing when determining the best route?
Bandwidth
Path availability
Path reliability
Communication costs
Definition of Routes
The path is used by data packets to reach a specified destination.
Characteristics of Routes
Added to the routing table.
Contains information about connected and remote networks.
Connected networks directly attached to router interface:
Gateways for hosts on different networks.
Remote networks:
Manually configured on the router.
Set automatically using dynamic routing protocols.
Give the full routing process
The router receives data and reads the destination IP address.
The router reads the routing table to determine which route to use.
The router replaces the existing destination MAC address with the MAC address for the
Give the full process of Local and Remote Delivery Process
The node applies the subnet mask to its own IP address to determine its own network ID.
The node applies the subnet mask to the packet’s destination address to determine the destination network ID.
Once the node has applied the subnet mask, it compares the two network IDs.
If they are the same, then the two nodes are on the same subnet, and the node can deliver the packet.
If the two networks are different, then the two nodes are remote to each other, and the data is routed to the remote network.
Definition of Routing Tables
A database is created manually or by a route-discovery protocol that contains network addresses as perceived by a specific router.
Give all the characteristics of a routing table
Routers use them to decide where to forward packets.
Packets are forwarded from router to router until the destination network is reached.
Features:
You can specify a maximum hop count.
You can specify a route’s cost.
Metrics help quantify which route should be used.
Give the routing table entries
Direct network routes
Remote network routes
Host routes
Default routes
Give a description of the default gateway
Destination: 0.0.0.0.
Appears if the local host has been configured with a default gateway address.
Give a description of a local loopback
Destination: 127.0.0.1
Provides a delivery route for packets addressed to the local loopback address.
Give a description of a local subnet
Destination: network portion of local IP address plus host address of all 0
Identifies the route to the local network. An example is 140.125.0.0.
Give a description of a network interface
Destination: local IP address
Identifies the route to the host’s local network card. An example is 140.125.10.25.
Give a description of subnet broadcast access
Destination: network portion of local IP address plus host address of all .255
Identifies the route for broadcasts on the local subnet. An example is 140.125.255.255.
Give a description of a multicast broadcast address
Destination: 224.0.0.0
Identifies the address for sending multicast transmissions.
Give a description of an Internetwork broadcast address
Destination: 255.255.255.255
Identifies the route for broadcasts to the entire network. However, most routers will not pass these broadcasts.
Give a full description of the network destination address
Contains the network ID of a destination address.
Is the search point when processing the routing table.
Can be listed as a complete address, but the router will be more efficient if listed as a network ID.
Give a full description of a network mask
Specific to each routing entry.
Determines how much of a packet’s destination address needs to match the network destination field of a routing entry before that route is used to deliver the packet.
Give a full description of a gateway
Indicates the address where the packet is delivered on its first hop.
Can be the local loopback address, a local IP address, the host’s own default gateway address, or the address of an adjacent router.
Give a full description of an interface
The IP address of the local port that a host uses to send data.
Once a destination entry is found, data is sent to the interface entry listed in the same line as the destination.