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CompTIA Network+ N10-008 (updated)
Client A device used by an end-user to access the network Server A device that provides resources to the rest of the network Hub Older technology that connects network devices together Can lead to increased network errors Wireless Access Point (WAP) A device that allows wireless devices to connect to a wired network Switch A device that connects network devices together (like a next generation hub). Can learn which devices are connected to which ports. Router Connects two different networks together and forwards traffic to and from a network Layer 3 device Media connects two devices or a device to a switch port Wide Area Network (WAN) link physically connects two geographically dispersed networks Client/Server model Uses a dedicated server to provide access to files, scanners, printers, and other resources Administration and backup are easier Client/Server benefits
- centralized administration
- easier management
- better scalability Client/Server Drawbacks
- higher cost
- requires specialized OS
- Requires dedicated resources Peer-to-peer model Peers share resources (files/printers) directly with others Peer-to-peer benefits
- lower cost
- no dedicated resources
- no specialized OS Peer-to-peer drawbacks
- decentralized management
- inefficient for large networks
- poor scalability Personal Area Network (PAN) Smallest type of wired or wireless network and covers the least amount of area Ex. Bluetooth, USB Local Area Network (LAN) Connects components within a limited distance Up to a few hundred feet Ex. Small office IEEE 802. Ethernet IEEE 802. Wi-Fi Campus Area Network (CAN) Connects LANs that are building-centric across a university, industrial park, or business park Up to a few miles Metropolitan Area Network (MAN) Connects scattered locations across a city or metro area up to about 25 miles Wide Area Network (WAN) Connects geographically disparate internal networks and consists of leased lines or VPNs worldwide coverage Physical how devices are connected by media Logical how the actual network traffic flows Bus Topology
Uses electromagnetic fields to read data stored in embedded tags Near Field Communication (NFC) Enables two devices to communicate within a 4-cm range Infrared (IR) operates with line of sight Z-Wave provides short-range, low-latency data transfer with slower rates and less power consumption than Wi-Fi used for home automation commonly ANT+ collection and transfer of sensory data ANT+ = sensors Physical Layer Where transmission of bits across the network occurs and includes physical and electrical network characteristics Time Division Multiplexing (TDM) Each session takes a turn, using time slots, to share the medium between all users Statistical Time Division Multiplexing (STDM) Dynamically allocates the time slots on an as-needed basis Frequency Division Multiplexing (FDM) Divides the medium into channels based on frequencies and each session is transmitted over a different channel Multiplexing simultaneous use of a baseband connection Physical Layer Devices
- Cables (media)
- Bluetooth, Wi-Fi
- Hubs, APs, Media Converters Data Link Layer Packages data into frames and transmits those frames on the network Media Access Control (MAC) Physical addressing system of a device which operates on a logical topology Uses a 48-bit hexadecimal address assigned to a network interface card (NIC) Logical Link Control (LLC) Provides connection services and allows acknowledgement of receipt of messages. Limits the amount of data that a sender can send at once to prevent the receiver from overloaded
The most basic form of flow control. Provides basic error control functions using a checksum Isochronous mode Network devices use a common reference clock source and create time slots for transmission Synchronous mode Network devices agree Asynchronous mode Network devices reference their own internal clocks and use start/stop bits Data Link Layer Devices NIC, Bridge, Switch Network Layer Forwards traffic (routing) with logical address Packet switching data is divided into packets and then forwarded Circuit Switching Dedicated communication link is established between two devices Message Switching Data is divided into messages which may be stored and then forwarded Route Discovery and Selection Manually configured as a static route or dynamically through a routing protocol Connection Services Augment Layer 2 connection services to improve reliability Internet Control Message Protocol (ICMP) Sends error messages and operational information to an IP destination. Used to communicate information about network connectivity issues back to the sender Layer 3 Devices Routers, Layer 3 switches (multilayer switch) Transport Layer responsible for providing communication with the application by acknowledging and sequencing the packets to and from the application Transmission Control Protocol (TCP) Connection-oriented protocol that is a reliable way to transport segments across the network User Datagram Protocol (UDP) Connectionless protocol that is an unreliable way to transport segments across the network TCP attributes
Used to scramble the data in transit to keep it secure from prying eyes and provide data confidentiality Presentation Layer Examples Scripting languages, standard text, pictures, movie files, encryption algorithms Application Layer Provides application-level services where users communicate with the computer Application Services Unites communicating components from more than one network application Service Advertisement Sending out announcements to other devices on the network to state the services they offer Application Layer Protocols POP3, IMAP, SMTP, HTTP, HTTPS, DNS, FTP, FTPS, SFTP, Telnet, SSH, Encapsulation The process of putting headers (and sometimes trailers) around some data Protocol Data Unit (PDU) A single unit of information transmitted in a computer network TCP Header 20 bytes SYN (synchronization) Used to synchronize connection during the three-way handshake ACK (acknowledgment) Used during the three-way handshake, but also used to acknowledge the successful receipt of packets FIN (Finished) Used to tear down the virtual connections created using the three-way handshake and the SYN flag. RST (Reset) Used when a client or server receives a packet that it was not expecting during the current connection PSH (Push) Used to ensure data is given priority and is processed at the sending or receiving ends URG (Urgent) Similar to PSH and identifies incoming data as urgent UDP Header 8 bytes
IP Header Ethernet Header Segment Source and destination ports Packet Source and destination IP addresses Frame Source and destination MAC addresses Bits transmitting layer 2 frames as a series of 1's and 0's Network Interface Layer (TCP/IP) Describes how to transmit bits across a network and determines how the network medium is going to be used. Internet Layer (TCP/IP) where data is taken and packaged into IP datagrams Application Layer (TCP/IP) Dictates how programs are going to interface with the transport layer by conducting session management Transport Layer (TCP/IP) Defines the level of service and the status of the connection being used by TCP, UDP, or RTP Port A logical opening on a system representing a service or application that's listening and waiting for traffic File Transfer Protocol (FTP)
Used for receiving incoming emails Port 110 Network Time Protocol (NTP) Used to keep accurate time for clients on a network Port 123 Network Basic Input/Output System (NetBIOS) Used for file or printer sharing in a Windows network Port 139 Internet Mail Application Protocol (IMAP) A newer method of retrieving incoming emails which improves upon the older POP Port 143 Simple Network Management Protocol (SNMP) Used to collect data about network devices and monitor their status Ports 161, 162 Lightweight Directory Access Protocol (LDAP) Used to provide directory services to your network Port 389 Hypertext Transfer Protocol Secure (HTTPS) Used for secure web browsing Port 443 Server Message Block (SMB) Used for Windows file and printer sharing services Port 445 System Logging Protocol (Syslog) Used to send logging data back to a centralized server Port 514 Simple Mail Transfer Protocol Transport Layer Security (SMTP TLS) Secure and encrypted way to send emails Port 587 Lightweight Directory Access Protocol - Secure (LDAPS)
Provides secure directory services Port 636 Internet Message Access Protocol over SSL (IMAP over SSL) Secure and encrypted way to receive emails Port 993 Post Office Protocol version 3 over SSL (POP3 over SSL) Secure and encrypted way to receive emails Port 995 Structured Query Language Server Protocol (SQL) Used for communication from a client to the database engine Port 1433 SQLnet Protocol Used for communication from a client to an Oracle database Port 1521 MySQL Used for communication from a client to the MYSQL database engine Port 3306 Remote Desktop Protocol (RDP) Provides graphical remote control of another client or server Port 3389 Session Initiation Protocol (SIP) Used to initiate VoIP and video calls Ports 5060, 5061 Generic Routing Encapsulation (GRE) Used as a simple and effective way to create a tunnel, called a GRE tunnel, over a public network. Does not provide encryption Internet Protocol Security (IPSec) Used to protect one or more data flows between peers Allows for:
- Data confidentiality
- Data integrity
RJ- 11
phone networks Bandwidth Theoretical measure of how much data could be transferred from a source to its destination Measures how many bits the network can transmit per second Throughput Actual measure of how much data transferred from a source to its destination cat 10BASE-T, 10 Mbps, 100 m Cat 100BASE-TX, 100 Mbps, 100 m Cat5e 1000BASE-T, 1 Gbps. 100 m Cat 1000BASE-T, 1 Gbps, 100 m 10GBASE-T, 10 Gbps, 55 m Cat6a 10GBASE-T, 10 Gbps, 100m Cat 10GBASE-T, 10Gbps, 100 meters Cat 40GBASE-T, 40Gbps, 30 meters Straight-Through Cable (Patch Cable) Contains the exact same pinout on both ends of the cable Data Terminal Equipment (DTE) "Endpoint" devices that connect to a piece of data communications equipment or DCE (e.g. laptops, desktops, servers, and routers) Data Communications Equipment (DCE)
Includes things like switches, modems, hubs, and bridges Crossover Cable Swaps the send and receive pins on the other end of the cable when the connector and its pinout are created switch to a switch Medium Dependent Interface Crossover (MDIX) An automated way to electronically simulate a crossover cable connector even if using a straight-through patch cable 568A
- White Green
- Green
- White Orange
- Blue
- White Blue
- Orange
- White Brown
- Brown 568B
- Orange/white
- orange
- green/white 4.blue
- blue/white
- green
- brown/white
- brown Plenum cable A special coating put on a UTP or an STP cable that provides a fire-retardant chemical layer to the outer insulating jacket Fiber Optic Cable
Angled Physical Contact (APC) Connector better signal, less noise green connector Ultra Physical Contact (UPC) Connector worse signal, more noise blue connector Wavelength Division Multiplexing (WDM) Combines multiple signals into one signal and sends over a single fiber optic strand using different wavelengths of the laser light source Coarse WDM (CWDM) Up to 18 channels 20 nm Up to 10 Gbps (ethernet) Up to 16 Gbps (Fiber Dense WDM (DWDM) Up to 80 channels 0.8 nm Up to 8 Tbps (100 Gbps/channel) Media Converter/Transceiver Converts media from one format to another bidirectional known as half-duplex communication where devices must take turns to communicate think walkie talkie Duplex known as full duplex communication where devices are able to communicate at the same time think phone call
GBIC
Standard, hot-pluggable gigabit Ethernet transceiver (copper or fiber) Small Form Factor Pluggable (SFP) Up to 4.2 Gbps SFP+ Up to 16 Gbps Quad Small Form Factor Pluggable (QSFP) Up to 40 Gbps QSFP+ Up to 41.2 Gbps QSFP Up to 100 Gbps QSFP Up to 200 Gbps Cable Distribution System An organized system that connects the network's backbone in the MDF to the IDF and finally to the end user's wall jacks. Demarcation Point Where the Internet service provider's connection ends and your network begins Backbone switch Connects to everything on the network Main Distribution Frame (MDF) A telecommunications closet which serves as the main starting point for all interior cabling "trunk of the tree" Cable Tray A unit or assembly of units that form a rigid structural system to securely support the cables and raceways Intermediate Distribution Frame (IDF) Contains an edge switch, a patch panel, and other associated equipment to support the floor and offices nearest to it 66 Block (M Block) 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 110 block Supports high speed data networks for CAT 5 and above and includes the use of insulation displacement contract connectors most common
Analyzes source MAC addresses and makes intelligent forwarding decisions based on the destination MAC in the frames Layer 3 Switch Makes Layer 3 routing decisions and then interconnects entire networks, not just network segments Link Aggregation (IEEE 802.3ad) Combines multiple physical connections into a single logical connection to minimize or prevent congestion Power Over Ethernet (PoE 802.3af, PoE+ 802.3at) supplies electrical power over ethernet and requires Cat5 or higher copper cable PoE 802.3af up to 15.4 watts PoE+ 802.3at up to 25.5 watts Port Monitoring or Mirroring Makes a copy of all traffic destined for a port and sends it to another port User Authentication (802.1x) Requires users to authenticate themselves before gaining access to the network Out-of-band (OOB) management keeps all network configuration devices on a separate network First-Hop Redundancy Uses Hot Standby Router Protocol (HSRP) to create virtual IP and MAC addresses to provide active and standby routers. First-Hop Redundancy Protocols Gateway Load Balancing Protocol (GLBP) Virtual Router Redundancy Protocol (VRRP) Common Address Redundancy Protocol (CARP) MAC Filtering Permits or denies traffic based on a device's MAC address Traffic Filtering Permits or denies traffic based on IP addresses or application ports Quality of Service (QoS) Forwards traffic based on priority markings Spanning Tree Protocol 802.1d Permits redundant links between switches and prevents looping of network traffic Blocking BPDUs are received but not forwarded Listening
Populates the MAC address table but does not forward frames Learning Processes BPDUs and this is where switch determines its role in the spanning tree Forwarding Forwards frames for operations Link Cost Associated with the speed of the link - the lower the link's speed, the higher the cost Virtual Local Area Network (VLAN) Allows different logical networks to share the same physical hardware and provides added security and efficiency VLAN Trunking 802.1q Multiple VLANs transmitted over the same physical cable Virtual Private Network (VPN) Creates a secure VPN or virtual tunnel over an untrusted network like the internet VPN concentrator Terminates VPN tunnels and allows for multiple VPN connections in one location VPN Headend A specific type of VPN concentrator used to terminate IPSec VPN tunnels within a router or other device Firewall A network security appliance placed at the boundary of a network Next-Generation Firewall (NGFW) Conducts deep packet inspection at Layer 7 and can look through traffic to detect and prevent attacks Intrusion Detection/Prevention System Recognizes and responds to attacks through signatures and anomalies Proxy Server A specialized device that makes requests to an external network on behalf of a client Content Engine/Caching Engine Dedicated appliance that performs the caching functions of a proxy server Content Switch/Load Balancer Distributes incoming requests across various servers in a server farm VoIP Phone A hardware device that connects to your IP network to make a connection to a call manager within your network Unified Communications (or Call) Manager Used to perform the call processing for hardware and software-based IP phones Industrial Control System (ICS) Describes the different types of control systems and associated instrumentation Supervisory Control and Data Acquisition (SCADA)
