Network+ 2023

Topology where the computers are connected on a loop or ring. Data flows in one direction only. FDDI ring is how you get redundancy.

A network that aggregates various forms of traffic such as voice, video, and data on the same network infrastructure.

The connection of devices to switches, such as copper cable, fiber, wireless, etc

The thing the connects your router to the outside world, like me paying COX

Where the client talks to a server and can be remotely administered from anywhere

Where data is stored on multiple different devices, can be very hard to manage if 50 separated devices need Microsoft office, they have to individually download it. Very cheap though.

personal network, smallest network, roughly 10ft max, items like usb web cam, car bluetooth, etc.

Can go as far as a few hundred feet

IEEE 802.3

IEEE 802.11

Large LAN such as college campus, large industrial complex, etc. Several buildings

metropolitan network, large connected network such as several police stations connected or multiple college campuses in a town

Large geographic coverage, can be across the world, the Internet is an example, big national company, the USG

A topology that describes the data-flow
patterns in a network.

A network layout in which there is one main trunk, or backbone, that all the various computers and network devices are connected to.

standard specifies that computers and devices on the network share or pass a special signal (token), like passing the talking stick

A topology with one central node that has each computer or network device attached to the central node. Single point of failure is the main device.

Similar to star topology but with multiple hub's connected together for sake of redundancy and routing efficiency.

every site has a direct connection to every other site; benefits: an optimal route exists between any two sites, fault tolerant, easy troubleshooting; drawbacks: difficult and expensive to scale. Only really worth it for insane projects like NASA.

Uses a wireless access point as a centralized point and supports wireless security controls.

Decentralized wireless network mode, otherwise known as peer-to-peer mode, where each wireless node is in meshed contact with every other node.

Interconnection of different types of nodes, devices, or radios which consists of clients, routers, gateways, and other devices. Wi-Fi, Bluetooth, microwaves, etc.

Collection and transfer of sensor data

Used with remote control systems (tire pressure, TVs, lights)

a seven-layer architecture for defining how data is transmitted from computer to computer in a network, from the physical connection to the network to the applications that users run.

Physical, Data Link, Network, Transport, Session, Presentation, Application

Data, segments, packets, frames, bits

Where transmission of bits across the network occurs and is focused on the physical and electrical characteristics of the network

communication that occurs when the communicators are sending and receiving messages at different times

communication that occurs in real time, uses a synchronized time clock

Baseband is for phone line or ethernet in your house, broadband is 200 channels over one cable for your TV box

Taking a limited resource and sharing it most efficiently.

Packages data into frames and transmitting those frames on the network, performing error detection/correction, and uniquely identifying network devices with an address (MAC), and flow control. Switches and Network bridges are devices in here.

Provides connection services and allows acknowledgement of receipt of messages, provides basic error correction

When networks share a common clock and schedule communication using the shared clock

Forwards traffic (routing) with logical address (e.g. IPv4 or IPv6), the determination of how to transmit data across the network using switching (routing).

Blocks out data as a packet and then sends that packet to the device, rinse and repeat. Can be different path to the device receiving every time

a dedicated connection is formed between two points and the connection remains active for the duration of the transmission

Data is divided into messages, similar to packet switching, except these messages may be stored then forwarded. Like sending a letter and the post office is closed for the day.

Manually configured as a static route or dynamically through a routing protocol. Various types but Layer 3 is how you decide what route to take.

A TCP/IP protocol that is used by devices to communicate updates or error information to other devices. FE - ping, checking time to respond and whether it made it to sites.

The only Layer 3 type of switch.

Routers, IP, multi layer switch (because it also functions as a router in a way).

A connection-oriented, guaranteed-delivery
protocol used to send data packets between computers over a network like the Internet. Uses SYN-ACK and verifies data is transmitted properly. Very reliable.

Syn - first check if server is ready to receive data from the client, Syn Ack - response back to client that they can receive info, Ack - starts data transmission from client to server.

connectionless protocol that does not require a connection to send a packet and does not guarantee that the packet arrives at its destination, uses datagrams. Not very reliable. Best for audio and visual. Super low overhead.

Data transfer types like UDP and TCP, almost always deals with segments because its most commonly TCP transmission.

The client can determine how much data it can receive at once. Can be raised or lowered based on needs. FE - time estimations that change a lot are windowing figuring out transmissions.

TCP, UDP, WAN Accelerators, Load Balancers, Firewalls

Keeps data transmissions separated to prevent intermingling and cross contamination of data transmitted through your network. Transfer of data, establishing or reestablishing the session, acknowledgement of receipt.

H.323, NetBIOS

A protocol for real-time data transfers (facetime or spotify).

Used to share files over the network.

Formats the data to be exchanged and secures that data with proper encryption.

Provides application-level services and is where the users communicate with the computer (FTP, Application Services, etc).

File transfer services, email services, DNS services, web hosting or connection, etc. The major services all applications rely on.

Hiding our datas details, moving up the chain of the OSI model

On a computer that receives data over a network, the process in which the device interprets the lower-layer headers and, when finished with each header, removes the header, revealing the next-higher-layer PDU.

A unit of data at any layer of the OSI model.

Synchronize a connection

Finish a connection

Reset a connection (tear down)

TCP; Indicates that the push function is to be performed. Push data up the stack as soon as possible

Packet contains urgent data, immediate processing for very important packets only.

It follows the Source MAC Address in a dataframe. It's 16 bits long and used to describe the protocol of the contents of the frame.

Application, transport, Internet, and network interface

Describes how to transmit bits across a network and determines how the network medium is going to be used.

Defines the level of service and the status of the connection being used by TCP, UDP and RTP.

Dictates how programs are going to interface with the transport layer by conducting session management. Includes HTTP, Telnet, SSL/TLS, SSH, DNS and several more.

Telnet

SMTP (Simple Mail Transfer Protocol)

DHCP (Dynamic Host Configuration Protocol), how devices on network auto get IP addresses

TFTP (Trivial File Transfer Protocol), FTP but only for config files and other lightweight files. Can also send "boot" commands

POP3 (Post Office Protocol), only INCOMING email

NTP (Network Time Protocol), used to keep time between network clients

NetBIOS, file or printer sharing in a windows network

IMAP (Internet Message Access Protocol), retrieves incoming messages in a better way than pop3

SNMP (Simple Network Management Protocol), collect info about network devices

LDAP (Lightweight Directory Access Protocol), directory services for your network

SMB (Server Message Block), file sharing and printer sharing in a windows network

System Logging Protocol (Syslog)
Used to send logging data back to a centralized server.

SMTP TLS/SSL, secure way to send mail, it's just SMTP but encrypted

Lightweight Directory Access Protocol (LDAP) Secure

IMAPS, secure version of IMAP and works the exactly same but encrypted

POP3 over SSL, same as POP3 but encrypted

Microsoft SQL Server, used to communicate to the database between machines

SQLnet Protocol
-Used for communication from a client to an Oracle database

MySQL, open source version of SQL

SIP (Session Initiation Protocol), used to initiate VoIP and video calls

A core protocol in the TCP/IP suite that notifies the sender that something has gone wrong in the transmission process and that packets were not delivered.

A tunneling protocol designed to encapsulate a wide variety of network layer packets inside IP tunneling packets.

Used to protect one or more data flows between two clients, encrypted and secured

An IPsec protocol that authenticates that packets received were sent from the source identified in the header of the packet.

Provides encryption and integrity for the data packets sent over IPsec.

A type of twisted pair cabling that does not include shielding around its conductors.

A type of cable containing twisted-wire pairs that are not only individually insulated, but also surrounded by a shielding made of a metallic substance such as foil.

telephone line connector

Transmission capacity through a media in a best case scenario

Actual measure of how much data transferred from a source to its destination

10BASE-T, 10Mbps, 100m length

100Base-TX, 100 Mbps, 100m length

1000Base-T, 1Gbps, 100m

1000Base-T or 10GBase-T (if short), 1Gbps or 10Gbps (if short), 100m or 55m

10Base-T, 10Gbps, 100m length

10GBase-T, 10Gbps, 100m

40GBase-T, 40Gbps, 30m

Orange/white, orange, green/white, blue, blue/white, green, brown/white, brown

And point device to connect to a piece of data communications equipment, or DCE.

Switch, modem, hub or bridge. Straight through cable is used to connect a client to this (DTE to DCE, or DCE to DTE)

568B to 568A, meant for switch to a switch
MDIX (media dependent interface

Modern switches will electronically allow 568B to 568B using this method so you don't need a crossover cable

White Green, Green, White Orange, Blue, White Blue, Orange, White Brown, Brown

A special coating put on a UTP or an STP cable that provides a fire retardant chemical layer to the outer insulating Jack, REQUIRED FOR UNSEEN CABLE

Fiber cable used for longer distances and has smaller core size which allows for only a single mode of travel for the light signal, long distance cables

A type of fiber optic cable used for shorter distances and has larger core size which allows for multiple modes of travel for the light signal, typically 2kms or less

subscriber connector. stick click. Little ridge on top.

Straight Tip, sick and twist to lock

Lucent Connector, the love connector (always side by side together), works like SC

The most common type of connector used with multimode fiber-optic cable. Small form factor.

Fiber-optic connector that makes physical contact between two fiber-optic cables. It specifies an 8-degree angle to the curved end, lowering signal loss. Green colored.

Fiber-optic connector that makes physical contact between to two fiber-optic cables. Blue colored.

Combines multiple signals into one signal and send over a single fiber optic strand using different wavelengths of the laser light source

Up to 18 channels on single fiber, up 40km, 10Gbps for Ethernet and 16Gbps to fiber.

80 wavelength channels over one fiber, up to 8Tbps total bandwidth possible, only really for ISPs and ocean floor cabling (insanely expensive)

Converts media from one format to another

Standard hot pluggable gigabit ethernet transceiver that can take in copper or fiber as its connector

A transceiver used to convert electrical signals to optical signals. Speeds up to 4.2Gbps, AKA mini-GBIC

enhanced SFP capable of 16Gbps

Compact, hot-pluggable optical module transceiver
Supports up to 40 Gbps

41.2 Gbps

Up to 100 Gbps

Up to 200 Gbps

An organized system that connects the network's backbone in the MDF to the IDF and finally to the end user's wall jacks.

The point of division between a telecommunications service carrier's network and a building's internal network.

The room in a building that stores the demarc, telephone cross-connects, and LAN cross-connects.

Common locations where cables from nearby offices terminate

Used in older analog telephone systems and older CAT 3 networks and supports a 25-pair cable that would run to the MDF or IDF

The most common connection used with structured cabling, connecting horizontal cable runs with patch panels. Meant for high speed data networks of Cat 5 and above.

An alternative to the 110 block that is proprietary and unique to Europe.

Another proprietary punch down block which is available in various sizes.

Each station connected to the network is ensured access for transmission of its messages at regular or fixed time intervals. Token Ring and Token Bus networks used this (dead).

Waiting for an appropriate time to interject into the network, commonly causes collisions since devices are uncoordinated. Ethernet actually uses this. Often best because not all devices need to hold bandwidth for a set time.

Prevents collisions by using carrier-sensing to defer transmissions until no other stations are transmitting. This is how ethernet avoids collisions in CBNs.

For the XBASE-XX ethernet standards of Fiber, only LX is an exception as it can be both.

A hub that receives data transmitted from a device on one port and broadcasts it out to the devices connected on all other ports. No amplification.

A type of hub that uses electronics to amplify and clean up the signal before it is broadcast to the other ports.

Active hub with enhanced features like SNMP, can be controlled at a distance.

A hub that regenerates the signal similar to
a repeater.

A hub that receives data transmitted from a device on one port and broadcasts it out to the devices connected on all other ports.

Multiple network segments are connected to each other via hubs. This is the main reason for a hub.

Breaks apart two collision domains to add security and network effciency

A bridge and a hub combined into one. It is essentially a multi port bridge and makes decisions based on MAC addresses.

A bridge, switch and network traffic organizer all in one. They can send traffic to the right route along with balancing traffic and collision domains.

A switch capable of interpreting Layer 3 data and works much like a router in that it supports the same routing protocols and makes routing decisions. Good for small networks, not a dedicated router.

Layer 2 device focused on MAC addresses.

Combines multiple physical connections into a single local connection.

Power over ethernet 15.4 watts

Power over ethernet 25.5 watts

Network configuration only network, connects to main network.

Spanning Tree Protocol

Defined by the IEEE 802.1D standard, it allows a network to have redundant Layer 2 connections, while logical preventing a loop, which could lead to symptoms such as broadcast storms and MAC address table corruption.

VLAN Trunking.
Multiple VLANs transmitted over the same physical cable.

A specific type of VPN concentrator used to terminate IPSec VPN tunnels within a router or other device

Layer 7 firewall that continuously monitors traffic to block threat actors and normal bad traffic

A server that acts as an intermediary between a user and the Internet. Meant for security for content filtering and logging.

A proxy server but only for caching pages that are visited commonly.

This is what the load balancer passes requests to in order to dish out the work load of website visits (such as amazon).

Industrial Control Systems, describes the different types of control systems associated with instrumentation

Supervisory Control & Data Acquisition:Acquires & transmits data from different systems to a central panel for monitoring & control.

The document that describes private IP ranges as a standard for the world.

10.0.0.0 - 10.255.255.255

172.16.0.0 - 172.31.255.255

192.168.0.0 - 192.168.255.255

The loopback address - localhost.

Automatic Private IP ranges, this means that the device failed to get an address from DHCP

Discover, Offer, Request, Acknowledge - when a machine cant get an address properly from DHCP

Giving one physical interface multiple IPs

One of the virtual interfaces on a single physical interface.

a message that is sent from a single sender to a single recipient

One source transmitting to multiple destinations on the network.

A single source transmitting to all sources on the network (FE radio).

Identifies NetBIOS systems on a TCP/IP network and converts those NetBIOS names to IP addresses, only works for Windows machines in a network.

Dynamically assigns IP addresses and allows a workstation to load a copy of their boot image over the network.

A service that enables a DHCP client
computer to configure itself automatically
with an IP address on the 169.254.0.0
network in case no DHCP servers respond to the client's DHCP discover broadcast.

Zeroconf - another version of APIPA, with some extra stuff such as mDNS for DNS lookup and assigning an IPV4 address with local link.

All just different versions of Zero Conf.

(the slash number)-24 = Y, 2^Y is the number of subnets possible in the Classless subnet

32 - (the slash number) = number of host IPs

Allows a network to be divided into different-sized subnets to make one IP network that would have previously been considered a class (such as Class A) look like Class B or Class C. A subnet of subnets.

Allows subnets of various sizes to be used and requires a routing protocol that supports it (basically every modern network does).

The CIDR /24 and above chart, with IPs and subnets listed.

Devices that can support both IPv4 and IPv6 address simultaneously.

Allows and existing IPv4 router to carry IPv6 traffic.

FE80 is the starting hex.

A feature of IPv6 in which a host or router can be assigned an IPv6 unicast address without the need for a stateful DHCP server.

Used to identify a set of interfaces and begins with FF.

Used to identify a set of interfaces so that a packet can be sent to any member of a set.

Allows a host to assign itself a unique 64-bit IPv6 interface identifier called an EUI-64. This is the MAC address + FF:FE in the middle of the address.

A protocol that is part of the IPv6 protocol suite, used to discover and exchange information about devices on the same subnet (neighbors). In particular, it replaces the IPv4 ARP protocol.

A data table stored in a router that lists the routes to particular network destinations

Allows a router to determine the best route between two nodes automatically and then store this information in a routing table.

Learned by physical connection between routers.

Prevents a route learned on one interface from being advertised back out of that same interface.

Causes a route received on one interface to be advertised back out of that same interface with a metric considered to be infinite.

Each router passes a copy of its routing table to its adjacent neighbors. The neighbor adds the route to its own table, incrementing the metric to reflect the extra distance to the end network. The distance is given as a hop count; the vector component specifies the address of the next hop.

How long it takes a group of routers to update their routing tables when a device drops off.

Hybrid of distance vector and link state protocols that uses bandwidth to display. Cisco only.

A link-state routing protocol used on IP networks. no hop count. fast convergence. multicast updates. Supports IPv4 and VLSM.

A path-vector protocol used by ISPs to establish routing
between one another. EXTERNAL PROTOCOL.

(NAT) A security technique that allows a LAN to use one type of IP address for intra-network data and another type of address for data traveling to and from the Internet

A port number is tracked with the client computer's private address when translating to a public address.

Type of NAT in which many computers can share a pool of routable IP addresses that number fewer than the computers.

When a single private IP address translates to a single public IP address. This is also called one-to-one mapping.

The address of the source as seen from inside the network.

The address of source as seen from the outside network.

The address of the destination as seen from the outside network.

The address of the destination as seen from the inside network.

Internet Group Management Protocol. Used for multicasting. Computers belonging to a multicasting group have a multicasting IP address in addition to a standard unicast IP address.

A multicast protocol used between multicast-enabled routers to construct a multicast distribution tree.

Delivers multicast traffic using a push model, rarely used.

Uses a shared distribution tree and creates an optimal distribution tree through shortest path tree (SPT) switchover.

A services that relays DHCP requests to DHCP servers that exist in remote networks.

Forwards several different kinds of UDP broadcasts across the router and can be used in conjunction with DHCP relay.