collaboration tools
tools that allow individuals to work together as a team on a project, no matter where they are located
cellular
technology in which a user can get access to the Internet when connecting a cell phone to a cell phone network
SAN
type of network infrastructure that stores, retrieves, and replicates data
fault tolerance
a network characteristic that restricts the impact of a failure on network access and allows a network to recover quickly from the failure
QoS
a mechanism to manage the flow of traffic based on different requirements to ensure reliable delivery of each type of traffic
BYOD
makes it possible for users to be free to use their personal devices to access a corporate or a campus network
cloud computing
technology that allows users and organizations to store data on remotely located servers on the Internet
data center
a facility used to store information originating from users or organizations
Powerline Networking
the connection of devices to the Internet through the use of existing electrical wiring
wiki
a web page that can be created and edited by a group of people
blog
web pages easily updated and edited by a person who wants to express his or her opinions about any subject
podcasting
a technology that allows people to access a website and download an audio recording delivered by someone
converged network
a network with the capability of delivering traffic with different requirements but with the use of the same network infrastructure
DSL
technology that provides the user with a high-bandwidth connection to the Internet over a telephone line
peer-to-peer network
a type of network in which computers can perform the role of a server and a client at the same time
intranet
a private interconnection of LANs and WANs inside an organization that can only be accessed by organization members or by non-members with authorization
extranet
a network that provides safe and secure access to an organization's data to authorized people who work outside that organization
Internet
the collection of globally interconnected networks
presentation layer
the layer in the OSI model that is responsible for formatting, compressing, and encrypting data
peer-to-peer network
consists of peer machines that exchange data with each other without a dedicated server
application layer
provides data exchange and the interface between the system and the network
domain name
the name that is used to uniquely identify a website and is used instead of the IP address
URL
Uniform Resource Locator - the "friendly" address that is used in a web browser bar and that corresponds to the IP address of the site
nslookup
a tool used to query the DNS system to find the IP addresses for domain names, and vice versa
session layer
used to arrange the communication between source and destination applications and responsible for the state of the conversation
client-server network
an architecture that allows network clients to request services directly from network servers
HTTP
Hypertext Transfer Protocol - used to request and transfer hypertext data between clients and servers
POP
a protocol that is used to retrieve email from a server It deletes messages from the server by default.
IMAP
a protocol that is used in email retrieval It leaves copy of messages on the server.
SMTP
the protocol responsible for sending email
DHCP
a service that is used in networks to automatically configure IP addresses on devices
Cisco IOS
term that represents the operating systems used by Cisco networking devices
shell
portion of operating system that interacts with applications and the user
kernel
portion of operating system that interfaces directly with computer hardware
GUI
a user-friendly interface that provides an interaction between a user and an OS through a graphical environment
console
a physical port of a Cisco device that provides access to the device via a dedicated management channel, also known as out-of-band access
keyword
parameter with a predefined value to be used by an IOS command
argument
parameter that has to be supplied by the user to an IOS command
startup configuration
file that is stored in NVRAM and that contains the configuration that has been saved on a device to be used upon startup or reboot
running configuration
file that is stored in RAM and that contains the configuration that is being done on a device
SVI
a logical interface used to remotely manage a switch over an IPv4 network
SSH
a protocol to establish a remote secure CLI connection over the network
ping
command to verify connectivity between the source (the device where the command is issued) and the destination (IP address used as argument)
traceroute
command to check the path that a packet takes to reach a destination
ipconfig
Windows command that shows the IP configuration settings on a PC
DHCP
a protocol that dynamically leases IPv4 addresses to DHCP-enabled end devices
encoding
process of modifying data to an acceptable format for transmission
decoding
process of modifying transmitted data into a format that is usable by a device
encapsulation
process of inserting a formatted message inside another formatted message
segmentation
process of splitting data into smaller pieces for transmission on a network
de-encapsulation
process of removing a formatted message from another formatted message
unicast
a form of message delivery in which a message is delivered to a single destination
multicast
a form of transmission in which a message is delivered to a group of hosts
broadcast
a form of transmission in which a message is delivered to all hosts on a network
open standard
refers to protocols that are available to the public at no cost
proprietary
refers to protocols that are developed by companies and are available to the public for purchase
PDU
the form of a piece of data that is associated with each protocol layer
default gateway
a router that is responsible for redirecting the packets it receives to their destination
bandwidth
the maximum rate at which data can be carried over a specific medium
throughput
the actual amount of data, in bits, that crosses a given point in a network over a certain period of time
goodput
the amount of usable data that crosses a given point in a network over a certain period of time
electromagnetic interference
interference that is caused when the electromagnetic field of one device affects the electromagnetic field of other devices
radio frequency interference
electromagnetic interference that is in the radio frequency range
crosstalk
occurs when the signals of one wire affect the signals on an adjacent wire
cancellation
the twisting of opposing wires to effectively eliminate crosstalk
header
information that is added before the data field in a frame
trailer
information that is added after the data field in a frame
physical topology
the actual connections and layout of devices in a network
logical topology
the way that the data travels through the network
contention-based access
nodes compete to be able to use the network medium
controlled access
when each node has an orderly opportunity to access the medium
frame check sequence
value of the field in a frame that is computed from the contents of the frame and determines if the frame has been damaged
full-duplex
devices are able to send and receive data simultaneously
half-duplex
devices are able to send and receive information, but only one direction at a time.
Organizationally Unique Identifier
a three-byte code that is assigned by IEEE to identify the vendor of a NIC
unicast
a message that is sent from a single sender to a single recipient
broadcast
a message that is sent from a single sender to all recipients
multicast
a message that is sent from a single sender to a group of recipients - more than one, but not all
physical address
a Layer 2 address that allows NICs to communicate with each other
logical address
a Layer 3 address that identifies both the network and the specific host on that network
Address Resolution Protocol
the process that is used to find a Layer 2 address when a Layer 3 address is known
auto-MDIX
a feature that detects the type of cable, and configures the interfaces to allow the connection
store-and-forward switching
a switching method that receives the entire frame before forwarding
cut-through switching
a switching method that begins the forwarding process as soon as enough information has been received to make a forwarding decision
fast-forward switching
a cut-through switching method that begins to forward data as soon as the destination address has been received
fragment-free switching
a cut-through switching method that begins to forward data after receipt of the first 64 bytes of a frame
routing
the process of sending packets to hosts on a remote network
maximum transmission unit
the largest PDU that is supported
Time-to-Live
a value that limits the the lifetime of a packet
administrative distance
the trustworthiness of a route
next-hop
the destination router indicated by the outgoing interface entry in the routing table
RAM
volatile memory that stores the running configuration and tables as generated by the device
ROM
nonvolatile memory that contains a limited IOS and instructions for the router
NVRAM
nonvolatile memory that stores the startup configuration of a device
hostname
a way to identify a networking device
flash
nonvolatile memory that stores the IOS and other system files
connectionless
a connection does not have to be established to send data
in-band configuration
requires the establishment of a network connection to the device to be configured
out-of-band configuration
requires a direct physical connection to the device to be configured
default gateway
a device that allows the devices on one network to communicate with devices on other networks
metric
a value that is used by a routing protocol to identify the best route to insert into a routing table
binary
a numbering system consisting of the digits 0 and 1, used by computers to perform operations
bit
a single binary digit, represented by a 0 or a 1
octet
one section of an IP address, consisting of a group of 8 bits
positional notation
determining a digit value based on the digit position, used in converting from one numbering system to another
subnet mask
a continuous sequence of 1 bits followed by a continuous sequence of 0 bits, used to determine the network portion of an IP address
ANDing
a binary process used to determine the network address of a host address by using the host address subnet mask
prefix length
the number of bits set to 1 in a subnet mask
network address
a dotted-decimal number that represents a unique IP network
host address
any IP address in an IP network that can be assigned to an interface
broadcast address
a dotted-decimal number that represents all hosts in an IP network
unicast address
the IP address of a single host on a network
multicast address
an IP address representing a selected group of hosts
public address
an IP address that can be routed on the Internet
private address
an IP address used internally and not routed on the Internet
classful addressing
specific ranges of IP addresses that make up classes of addresses in which the number of available network and host addresses are defined
classless addressing
IP addressing standards created in 1993 that allow address allocation based on prefix length rather than predefined class ranges
hexadecimal
a base-sixteen numbering system that uses numerals 0 through 9 and letters A through F to represent binary numbers in more condensed form
IPv6 link-local address
an IP address that is required for every IPv6-enabled network interface and that allows a device to communicate with other IPv6-enabled devices on the same link
ping
a utility that sends a series of echo requests from one IP host to another IP host and that processes the echo reply messages to test connectivity between the devices
traceroute
a utility that generates details about the route traveled by data sent between two devices
subnetting
the process of subdividing a network into smaller groupings of devices, or subnets
broadcast domain
an area within which a broadcast transmission will be shared
subnet
a subdivision of a network that is created either to conserve addresses or to support specific network requirements.
VLSM
allows subnets of different sizes to be created from the same network address
three levels of IP addressing hierarchy
network, subnetwork, host
two effects of excess broadcast traffic
1 - slow networks due to excess traffic, 2 - slow devices due to the need to process broadcasts
three classful prefix-lengths
/8, /16, /24
2^n formula
calculates the number of subnets created for n bits borrowed
2^n-2 formula
calculates the number of hosts per subnet for n bits remaining in the host field
the subnet mask for prefix /26
255.255.255.192
structure of IPv6 unicast addresses
48-bit global routing prefix, 16-bit subnet ID, 64-bit interface ID
gateway
a device that allows hosts on one network to communicate with hosts on other networks
port numbers
numbers that are assigned to the source and destination at Layer 4 to uniquely identify the communication
conversation multiplexing
the combining of many different conversations into one data stream
segment
a block of application data created to facilitate network transport
TCP
a connection-oriented reliable protocol that uses a 3-way handshake
UDP
a connectionless protocol that has little overhead and is used for communication data such as voice and video
best effort delivery
a data delivery method that has no service guarantee
session
a connection between systems
connection-oriented
used to describe the reliable nature of TCP. The connection refers to the 3-way handshake required in TCP before data transmission.
flow control
a mechanism that is used with TCP to control the amount of traffic that is sent from the source to the destination
datagrams
the name of the UDP PDU
source port
a value between 1024 and 65535 used to uniquely identify the source application or process on a local host
destination port
a port value that uniquely identifies the destination application
well-known ports
port numbers in the range of 1-1024 that identify network applications that are well known such as web, email, and remote login applications
dynamic ports
ports that are dynamically assigned to communication sessions as needed and are typically in the numerical range of 1024 to 65535
netstat
a utility that tracks TCP connections on network hosts
intermediate device
a device passing network traffic and connecting different networks
device capacity
the port density, processing, and memory capacity of a device
redundancy
the duplication of devices, links, or technologies to increase high availability
modular
a feature that allows add-in capabilities/technologies to a device without the need to purchase a whole new device
vulnerability
a weakness or flaw that can allow an attacker to gain access to a system
malware
unwanted malicious software that can harm or disrupt a system operation
virus
a type of malicious software that requires a user to spread the software through the network
worm
a type of malicious software that uses the network to spread the software and infect vulnerable systems
Trojan horse
hidden or disguised software that installs with another software package that a user requested
AAA
a framework that is used to implement authentication, authorization, and accounting functions into network operations
packet filtering
the ability to perform packet inspection at Layer 3 based on the source and destination IP addresses and source and destination port numbers
application filtering
the ability to filter traffic based on destination port numbers
URL filtering
the ability to filter traffic based on a web address
stateful packet inspection
the ability of a device to track TCP connections and only allow returning data to the inside connection