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Ethernet Basics–The Physical Network–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA Network+ (N10-007) NETWORK-PLUS Certification Prep Course Notes
The Physical Network Ethernet Basics What is Ethernet? The Ethernet frame (of data) never really changes! Max frame is 1,500 bytes. Ethernet is defined by the IEEE 802.3 standard. The IEEE has defined many versions of Ethernet. For the test, be able to recognize the Ethernet naming syntax. 802.3 standards: 802.3a 802.3b 802.3i 802.3ae and more Standard Nomenclature (for Ethernet): 10 Base 5 ’10’ is the speed in Mbps ‘5’ is the length of the cable (5 for 500m, But today the only value we’ll see here is ‘T’.) ‘Base’–only one channel on the entire bandwidth. or, ‘Broad’–Broadband is ethernet that runs like cable TV (with lots of channels or…
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Cabling & Topology–The Physical Network–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA Network+ (N10-007) NETWORK-PLUS Certification Prep Course Notes
The Physical Network Cabling & Topology Network Topologies ‘Star-Bus’ topology is considered a hybrid topology. When each host is interconnected this is considered a fully meshed topology. Logical topology is the electronic circuit flow of frames. Topology is the organization of how the 1’s & 0’s (binary data) in the form of frames, move from host to host. Star-Bus topology is the primary topology that we use today. Ethernet uses exclusively ‘Star-Bus’. If you’re plugging a computer into a network, it’s probably using Ethernet, & it’s probably using ‘Star-Bus’. MESH is a topology that’s pretty much unique to wireless networks. Everybody connects to everybody else. Fully meshed vs partially meshed…
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Understanding Networks–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA Network+ (N10-007) NETWORK-PLUS Certification Prep Course Notes
Understanding Networks Network Models What is a model? Models are used to represent how networks function. There are 2 very popular network models: the OSI 7-Layer model, & the TCP/IP model OSI Model vs. TCP/IP Model OSI Model (older; more detailed) 7- Application 6- Presentation 5- Session 4- Transport 3- Network 2- Data Link 1- Physical TCP/IP Model (more modern; not as detailed/complicated/more simplified) 4- Application 3- Transport 2- Internet 1- Network Interface (Link) Notes: The OSI model is being supplanted with the TCP/IP model. The TCP Internet layer most closely matches the OSI Network layer. Meet The Frame (Packets) Devices on a network send & receive data in discreet…
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Security & Organization–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA A+ (220-1001) A-PLUS Certification Prep Course Notes
Securing Computers Threats The term “security” encompasses host- and network-based security, and physical security. Common threats include man-in-the-middle attacks, DoS, and DDoS attacks. Symptoms of such attacks (Flags!) include renamed system files, missing files, & more. DoS–Denial of Service; DDoS–Distributed Denial of Service. Zero Day–a new threat that no one has seen before. Dealing With Threats Host-based security includes patching, anti-malware, and a firewall. Network-based security includes IDS, IPS, & firewalls. UTM (Unified Threat Management) includes IDS/IPS, firewalls, and anti-malware; available in the cloud. IDS–Intrusion Detection Systmes IPS–Intrusion Prevention Systems; these systems are more active! Endpoint Management Physical Security Physical security includes perimeter security, room locks, and individual device security.…
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The Essentials of Networking–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA A+ (220-1001) A-PLUS Certification Prep Course Notes
The Essentials of Networking Network Card Troubleshooting Use Device Manager –> NIC properties for information/configuration. Change duplex and wake-on LAN settings there Link lights show connectivity, activity, and (sometimes) speed. Full-Duplex–the NIC is talking & listening at the same time. Half-Duplex– Wake-on LAN–wakes up a computer from sleeping if certain information comes in (a so-called ‘magic packet’). Working With Connections–NETSTAT The ‘netstat’ command shows important information about connections. Use netstat switches ‘-n’ and ‘-a’ as needed. Consider a 3rd-party tool, such as TCPView as an alternative to netstat. TCPView is from SysInternals website. Netstat–shows statistics for different connections (usually TCP/UDP) ex: Windows folder sharing–(Port 445) TCPView is a ‘3rd-party’ tool…
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Building a P.C.—NETWORKING ESSENTIALS—CompTIA A+ (220-1001) A-PLUS Certification Prep Course Notes
Building a P.C. The Right PC for the Job Memorize details about each specialized system. Consider different jobs & make sure the system matches the job specifications. Concentrate on RAM, storage, & graphic needs. NAS–Network Attached Storage; used for sharing files; Usually a “headless” set-up, meaning no peripherals needed, after the initial set-up. Boot From Everything Use an ISO image of bootable media to install operating systems. Download ISO files and burn them to optical media or thumb drives. Boot to the installation media to install operating systems. You can also boot from a network server using PXE. Installing Windows Check all pre-installation tasks before installing Windows. Research new hardware…
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Understanding Partitioning—Implementing Mass Storage–NETWORKING ESSENTIALS—CompTIA A+ (220-1001) A-PLUS Certification Prep Course Notes
UNDERSTANDING PARTITIONING A partition is a logical electronic device readable by an Operating System. Partitions define the location of operating systems, swap files, and recover partitions. Partitions must be created & mounted. In Windows, partitions manifest as driver letter; in Linux/macOS, partitions manifest as folders (with slashes). Partitioning a hard drive is CRITICAL!!! MBR Partitioning MBR (Master Boot Record) is the oldest type of partition still in use today. MBR consisted of a boot loader, and up to four partitions, with one set as an active partition. If you need more than four partitions on a single drive, you create an extended partition and add logical drives to that partition.…
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Printers & Multifunction Devices—NETWORKING ESSENTIALS—CompTIA A+ (220-1001) A-PLUS Certification Prep Course Notes
Printers & Multifunction Devices Laser Printers A laser hits the photosensitive drum (the cornerstone of laser printers) to create an image Memorize the laser printing process Laser printer maintenance means replacing the toner cartridge and applying maintenance kits. All laser printers have maintenance kits. These can help the printers last for years! Inkjet Printers (aka Bubblejet Printers) CYMK (Cyan, Magenta, Yellow, & Black) Inkjet printers use heat or mechanical process to push ink through the print heads to media. A multifunction device (MFD) includes a printer, scanner, copier and fax machine, all-in-one. Inkjet maintenance means running cleaning routines for the nozzles, plus some form of calibration. Impact Printers (aka DotMatrix)…
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Wireless Networking—NETWORKING ESSENTIALS—CompTIA A+ (220-1001) A-PLUS Certification Prep Course Notes
Wireless Networking Wireless Network Hardware A wireless access point (WAP) bridges 802.11 and Ethernet networks Wireless clients connect to WAPs 802.11 works in one of two modes: infrastructure mode, or ad hoc mode Use correct antenna for the job In many of today’s laptops the antenna is built into the laptops monitor itself. (SSID)-Service Set Identifier (SSID) Wi-Fi Standards 802.11 uses the 2.4- and 5-GHz ISM band 802.11 uses remade channels Memorize the band usage and relative speeds of the 802.11 extensions. (ISM) Industrial, Scientific, and Medical Radios Bands 2.4 GHz and 5 GHz Band Band is a range of radio frequencies 2.4 GHz Band: 2.412-2.4884 GHz Uses different “channels”…
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Local Area Networking—NETWORKING ESSENTIALS—CompTIA A+ (220-1001) A-PLUS Certification Prep Course Notes
LOCAL AREA NETWORKING Intro to TCP/IP ARPANET formed (basis for Internet) TCP/IP adopted as protocol for ARPANET/the Internet IP addresses have four octets between 0-255 (a total of 256 options) Classful address scheme for locations & sublocations. Class A—6.x.x.x Only 1st number is locked millions of hosts Class B—172.16.x.x First 2 numbers are locked/set 65,534 hosts Class C—210.11.12.x First 3 numbers are locked/set) 254 hosts Network IDs and Subnet Masks Use Network & Sharing Center for setting up network information Set IP address, subnet mask, and gateway in Ethernet Properties Manual settings = static IP address Private IP Addresses: Class A—10.x.x.x Class B—172.16.x.x, 172.31.x.x Class C—192.168.x.x Special IP Addresses Class…