1.3 Explain the concepts and characteristics of routing and switching. Flashcards
Broadcast domains
A set of devices on a network that can hear broadcast traffic from each other.
ARP Requests
Broadcasts Look to resolve a known IP addresses by finding an unknown mac address of that device. they are always broadcast and heard by every device on the network.
How is an ARP request sent?
ARP broadcasts a request packet to all the machines on the LAN and asks if any of the machines are using that particular IP address.
CSMA/CD
Carier sense multiple access with collision detection.
A media access control method that was widely used in Early Ethernet technology/LANs when there used to be shared Bus Topology and each node ( Computers) were connected By Coaxial Cables. This protocol decides which station will transmit when so that data reaches the destination without corruption.
CSMA/CA
Carier sense multiple access with collision avoidance.
Used by Wi-Fi
Collision domains
all devices that can have their messages collide with messages from other deivces.
Full Duplex comminications
Devices can transmit to the switch port and switch port cna send to device at the same time.
WiFi networks are based on
IEEE 802.11 standards
Hidden node problem
Wireless devices can both be of a AP but not each other. They cant sense when the other is talking so can send traffic to the AP at the same time creating a collision.
what is a PDU
(Protocol Data Unit) Represents a specific set of data at each layer.
PDU of layer 7
data
PDU of layer 6
data
PDU of layer 5
data
PDU of layer 4
segment or datagram
PDU of layer 3
packet
PDU of layer 2
frame
PDU of layer 1
bits/bytes
Maximum transmission unit (MTU) of ethernet
Max 1500 bytes consisting of an IP header and data can be placed inside of an Ethernet frame.
multicast
single device sends a packet to a group of interestd computers
unicast
one device sends a message directoly to another device
VLANS
Segment a network into various departments and components.
what is trunking 802.1q
process of transferring VLAN traffic between two or more switches.
trunk port
port on a switch configured to carry all traffic regardless of VLAN number. Enables same vlans hosted on multiple switches to talk to each other.0
802.1q tagging standard
allows frames to e sent within a VLAN.
NAT
Network Address Translation. a process that enables one, unique IP address to represent an entire group of computers. In network address translation, a network device, often a router or NAT firewall, assigns a computer or computers inside a private network a public address.
DMZ
area of the network carved out by a single or multiple firewalls to provide a special place on the network servers need to be publicly accessible from the internet.
802.3
IEEE Ethernet standard
PoE
802.3af…
Port Mirroring
Managed switches can copy data from any or all physical ports on a switch to a single physical port.
Advantage of port mirroring
With port mirroring enabled, the packets can be monitored and analyzed.
Fault Tolerance
ability to continue operating despite failures or malfunctions.
ARP Cache
When a device wants to communicate with another device on the same local network, it checks its ARP cache to find the MAC address associated with the desired IP address.
Distance-vector routing protocols
use one of several algorithms to determine the best route to other routers based on the cost (distance) and director (vector)
Access control list
Collection of statements applied to an interface that can permit or deny traffic.
Do ACLs have an implicit deny?
Yes. Automatically deny any packets that don’t match a rule. Maybe write a line to permit traffic that wasn’t dropped by the first rule.
Distributed switching
seperate phyiscal switches act as a single switch.
VVS Virtual Switching System
Virtual Switching System (VSS) is a technology developed by Cisco that allows two physical switches to operate as a single logical switch. Let’s dive into the details:
Overview:
A VSS combines a pair of Catalyst 6500 series switches into a single network element.
The VSS manages redundant links, which externally act as a single port channel.
It simplifies network configuration and operation by reducing the number of Layer 3 routing neighbors and providing a loop-free Layer 2 topology12.
Port forwarding
Allows outside services to access internal network. Sets up public services on your network such as web servers, FTP servers, e-mail servers, or other specialized Internet applications. Also known as a static route or destination NAT.
Routers and switches were designed with two closely integrated parts:
A control plane makes decision on how to move traffic. Data plane responsible for executing those decisions.
SDN
Cuts the control plain of individual devices out of the picture and lets an all knowing program called a network controller. can dictate how both physical and virtual network components move traffic through the network.
Neighbor discovery
a protocol used for IPv6 traffic that allows different nodes on the same link to advertise their existence to their neighbors, and to learn about the existence of their neighbors.
Diffserv
the underlying architecture that makes QoS work
Traffic shaping
QoS through bandwidth management. you control the flow of packets into or out of the network according to the type of packet or rules.
QoS
polices that prioritize traffic based on certain rules. These rules control how much bandwidth a protocol, PC, user, VLAN or IP address may use.
What breaks up a broadcast domain.
Router
Switch will forward a broadcast to all ports extept
the interface the message came from.
whatis half duplx
older tech. when a node come only transmit or receive at one time, not simultaneously.
what is carrier sense
means that each machine on the network examines the cable before sending a data frame
multiple access
all machines have equal access to the wire.
What is a collision
when two nodes use the cable simultaneously
can wifi transmit and receive at the same time?
name three distance vector routing protocols
RIPv1, RIPv2, EIGRP
what is a hop?
each time a packet goes through a router
RIPv1
– Port 520. Uses hop count as a routing metric to find the best path between the source and the destination network. A Dynamic Routing Protocol. Works in Network Layer 3
RIPv2
RIPv2 is a classless, distance vector routing protocol as defined in RFC 1723.
EIGRP
a distance vector routing protocol.
what is IPv6 addressing
a 128-bit address displayed in hexadecimal format and not the dotted decimal notation that is used by IPv4.
two things about ipv6
Not case sensitive and do not need to place leading zeros at the beginning of a hextet.
hextet
unofficial name of one of the eight groups of 16-bit groups.
6 to 4 tunneling
tunneling protocol that enables ipv6 traffic to use ipv4 without having to use explicit tunnels.
Three types of ways to send a frame or packet.
Broadcast, Multicast, Unicast.
Advantage of VLANS
Better security and performance.
802.3af
PoE
SPANNIng tree protocol STP
Elimate the problem of potential switching loops.
How does a Switch create a MAC address table
Creates a mac address for very computer on the network ny learning sorce mac address of frames.
Link State
A protocol where each router maintains a map of the network and updates it through link-state advertisements.
OSPF
Open Shortest Path First. a link-state routing protocol that is used to find the best path between the source and the destination router using its own Shortest Path First.
Routing Information Protocol (RIP)
is one of the oldest distance-vector routing protocols which employs the hop count as a routing metric.
