CompTIA Network+ (N10-008) (Retired)

Explore the OSI model as a learning tool, clarify that it is not a protocol, contrast it with TCP/IP, and outline layer roles, PDU concepts, and its value for troubleshooting.

Explore layer one of the OSI model, the physical layer, where bits (the PDU) are passed with no fields or headers, by cables, connectors, modems, and Wi-Fi.

Explore the data link layer of the OSI model, where frames carry source and destination MAC addresses and devices like NICs, switches, and wireless access points enable LAN connectivity.

Explore layer three, the network layer, focusing on packets and source and destination IP addresses, and how routers and layer three switches enable wan connectivity across offices.

Explore the transport layer of the OSI model, comparing TCP segments and UDP datagrams, and learn how destination and source ports enable delivery of packets through firewalls.

Explore the OSI model’s layers five through seven—session, presentation, and application—and how they condense into the application layer, with data as the PDU and endpoints.

Encapsulate data with layer four, three, and two headers plus a footer to send from laptop to server. Decapsulate by removing headers in reverse order to recover original data.

Explore the Ethernet header as a layer two frame, including destination and source MAC addresses, plus how Wireshark displays the Ethernet header and related layer information.

Explore the IP header, focusing on the source and destination IP addresses, and learn to view IP information in Wireshark by capturing traffic and inspecting IPv4 fields.

Compare tcp and udp headers on the layer four protocol, showing when tcp is reliable for file transfers and databases, and udp for speed in voice and video, with Wireshark.

Discover how TCP flags during a three-way handshake establish a virtual circuit between client and server, demonstrated with Wireshark, nslookup, and a browser session to enable reliable data transfer.

Learn how payload comprises the application data plus its layer four through layer two headers. See how each layer adds to the payload.

understand the maximum transmission unit MTU and how bigger MTU like 9000 can speed transfers, while mismatched MTUs cause fragmentation and bottlenecks, especially when a router drops to 1500.

Explain partial and full mesh topologies, why full mesh is impractical for large networks, and how the internet backbone (AT&T) exemplifies a partial mesh.

Explain why the bus topology is largely obsolete, noting that a break in the middle cuts off communication between network segments, making it a short-lived legacy design.

Explore the ring topology, now mostly legacy except for internet provider fiber via Sonet, and learn why adding nodes is hard and two breaks split the network.

Explains star topology, or hub-and-spoke, with a central switch connecting many devices in a modern lan, and highlights the single point of failure and easy replacement of one switch.

Identify network types such as LAN, WAN, MAN, CAN, PAN, WPAN, and SAN, and explain their creation with switches, routers, access points, and backbone topology.

learn how software defined wide area network uses software to define networks instead of hardware. the SD-WAN controller enables the management and control planes to simplify configuring switches and routers.

Explore multiprotocol label switching (Mpls) as a wan technology that speeds internet traffic and enables better packet prioritization by labeling and forwarding packets.

Mgr, or multi-point generic routing encapsulation, is a VPN technology that dynamically connects clients to their VPN, creates and destroys tunnels, and simplifies configuring the remote office.

Identify the demarcation point, or D mark, where the internet enters a building, and understand the smart jack, an ISP device used for diagnostics and troubleshooting.

Explore virtual networking and NFV, turning network functions into virtual features like a virtual switch, v router, and v firewall, enabled by a hypervisor to reduce the number of devices.

Compare provider links such as DSL, cable, leased lines, metro optical, metro ethernet, and satellite like Starlink, noting rural limitations, speeds, and cost implications.

Twisted pair cables use copper and RJ-11 or RJ-45 connectors; twisting reverses polarity to cancel crosstalk and extend signal distance. Learn Cat 5, Cat 6, and the 100 m standard.

Explore Codex standards for coax cables that carry tv and internet signals. See how a modem terminates coax for internet access and why rg-6 is the current rating.

Explore DAC cables, Twinax, and AOC, direct attach copper with pre-attached SFPs, covering passive versus active variants, short reach, and data center interconnects for linking two switches with breakout options.

Understand T568A and T568B termination methods for RJ-45 and patch panels, when to use straight-through and crossover cables, and memorize the RJ-45 pinouts.

Explain the two fiber cable types, MMF and SMF, including their colors (orange/aqua for MMF, yellow for SMF), their differences for the exam, and note EMI immunity and core material.

Explore fiber connectors by form factor, including lc, st, sc, and mt, and compare upc and apc contacts, noting that apc reduces back reflection and improves network connectivity.

Explore copper connectors such as RJ-11 and RJ-45, their wire counts, 66 and 110 block terminations, and coax F, B, and C connectors, including crimping.

Learn how a media converter translates ethernet to fiber to connect two layer-2 switches, using the right SFP module for single- or multimode fiber.

Explore transceiver types such as SFP, SFP+, QSFP, QSFP+, and QSFP28, and learn how to install SFP modules and connect fiber to a layer two switch using a breakout cable.

Learn patch panels, aka 110 blocks, to organize networking closets and terminate ethernet with a punch down tool, and compare fiber distribution panels as the fiber equivalent of patch panels.

Explore punch down block types, including 66 legacy analog terminations, 110 blocks for ethernet RJ-45 terminations in network closets, the crown cross-compatible with 110, and Bix legacy 25-pair terminations.

Explain ethernet standards, including ten base T and ten g base T, with baseband and twisted pair concepts, and summarize fiber standards like 100 base fx, MMF, and SMF.

Compare the cli and gui in Cisco iOS, understanding how command line and graphical interfaces configure networking devices. Learn when gui visuals help and when cli speed and automation excel.

Discover why Cisco iOS powers most networking devices and leads ethernet switches and routers, with market shares of 45% and 35%.

Use the enable command to switch from user exec mode to privileged exec mode, and recognize the > and # prompts during a Cisco IOS lab.

Learn how the config t command, alias for configure terminal, is used in privileged exec mode to enter global configuration mode and configure Cisco devices.

Explore the various modes in Cisco's IOS, from user executable and privileged executable to global configuration mode and its dozens of interface and router configuration submodes.

Learn how the up arrow in Cisco's iOS cycles through previous commands in Packet Tracer to quickly reuse or fix mistyped entries, with a brief demo.

Master the question mark in Cisco's iOS to reveal command options and auto-complete commands, from user exec to config t, using spacebar navigation in Packet Tracer.

Use the tab key to autocomplete Cisco iOS commands in Packet Tracer, an alternative to shorthand. Practice typing commands on a 2911 router to see how tab completes them.

Learn how shorthand commands in Cisco iOS speed up command entry, with unique abbreviations like config t and int g01, while avoiding overlaps that cause ambiguity.

Learn to use cables in Cisco Packet Tracer by connecting a 2911 router to a 2960 switch with straight-through cables or the automatic connection option, selecting G0/0 and Gi0/1.

Demonstrate how to cancel the unintended network name search in Cisco Packet Tracer by pressing ctrl+shift+6, speeding up lab setup when DNS is not used.

Configure a PC in Cisco Packet Tracer using the config tab to set global settings, default gateway, and IP on Fast Ethernet 0; use the command prompt and web browser.

Demonstrate configuring Cisco's packet tracer servers, setting global default gateway and DNS, assigning a static IP address on Fast Ethernet zero, and exploring server services and their weaknesses.

Explore how to use the fast forward feature in Cisco's Packet Tracer to accelerate device convergence during labs, turning orange loading indicators to green as switches communicate.

Use the notes tool in Packet Tracer to attach interface details and IPs to a router, then edit, move, and save with escape key. Note: they do not configure devices.

Explore how sniffers in Cisco Packet Tracer capture traffic between devices by placing a sniffer between two switches, inspect individual packets, and understand directional limitations.

Explore IPv4, the internet protocol version four that still powers device communication across networks via IP addresses, with subnet masks and the default gateway.

Explore RFC 1918 and distinguish private IPs within your LAN from public IPs on the internet, including static and DHCP assignments managed by your ISP.

Perform a Cisco Packet Tracer prerequisite setup for NAT videos by configuring two routers, switches, PCs, and sniffers, assigning IPs, enabling EIGRP, testing connectivity, and saving the template.

Explore old-school static NAT, translating private IPv4 addresses to public ones and hiding internal networks. See how 1:1 mappings waste public addresses and why dynamic address translation was developed.

Explore dynamic address translation (dat), an evolution of old school nat that recycles a public ip for multiple private addresses while preserving lan security, and compare its limits to pat.

Explore port address translation (Pat), the modern, overload form of Nat that lets many private devices share a single public ip using unique ephemeral ports, with a real-world lab demonstration.

Learn how APIPA assigns 169.254.x.x addresses when DHCP is unreachable, what it means for network connectivity, and how to restore DHCP service with a configured DHCP server.

Examine unicast, multicast, broadcast, and anycast, detailing 1-to-1 connections, 1-to-many delivery with reduced bandwidth and latency, and LAN-wide broadcasts, plus anycast’s nearest-destination routing for fast, redundant traffic.

Master the loopback address 127.0.0.1 and localhost for local testing. Ping the loopback and set up a local web server on ubuntu using apache2.

Demonstrates the loopback address 127.0.0.1 and localhost for local testing, including ping tests and setting up a local web server with apache2 on an Ubuntu VM.

Learn how to calculate EUI-64 from a mac address to auto-generate IPv6 addresses, inserting fe in the middle and flipping the seventh bit to form the final IPv6 construct.

Compare classful and classless subnetting, and apply CIDR notation to design efficient IPv4 networks. Learn how binary math converts netmasks to prefix lengths and why classful addressing wastes addresses.

Learn how a virtual IP masks actual router addresses and redirects PCs to one of several routers for server clustering, load balancing, and router redundancy.

Explore VLAN fundamentals and 802.1Q tagging with a hands-on Packet Tracer demonstration, showing how layer two VLANs separate subnets and how inter-VLAN routing enables cross-subnet communication.

Explore how vlan trunk ports carry multiple vlans between switches, replacing access ports for vlan 20 and 30, with hands-on configuration and inter-vlan routing notes.

Configure router subinterfaces to enable inter-vlan routing on a single physical port using dot1q, with examples for vlan 20 and vlan 30 on a 2911 router.

Explore how switched virtual interfaces on layer 3 switches function as virtual default gateways for VLANs, with VLAN 20, IP addressing, and practical SVI configuration demonstrated.

Explains inter VLAN routing, connecting separate VLAN networks by routing traffic between them while enforcing subnet boundaries, enabling granular layer 3 and 4 filtering and improving security.

Explore inter vlan routing with a router on a stick, using a layer two switch and subinterfaces to route between vlan 20 and vlan 30.

Configure inter vlan routing with layer three switches by creating SVIs for vlan 20 and 30 and enabling ip routing.

Explore voice vlan by separating VoIP traffic from data on a single switch port, using two access vlans for pc and phone to prioritize voice traffic.

Binary math basics for networking: convert binary to decimal by counting bit positions from the right, using powers of two, and applying it to IP addresses and subnetting.

Master subnet mask conversions by practicing binary to decimal and decimal to binary, using octets and 255 values, with contiguous ones followed by zeros.

determine number of hosts per subnet by converting the subnet mask to binary, counting zeros, and calculating two to the power of zeros, then subtracting two to get usable hosts.

Determine usable subnets by two to the power of the ones in the mixed octet; calculate hosts as two to the power of zeros minus two.

Explore step four of subnetting by determining the mixed octet, calculating 126 usable hosts and two subnets, and identifying ranges 192.168.0.0 to 192.168.0.127 and 192.168.0.128 to 192.168.0.255.

Discover the shortcut for subnet ranges by using binary conversion, counting zeros in the mixed octet to yield 16 usable subnets, and count by 16 in the third octet (192.168.0.0).

Count IP addresses within a subnet by incrementing through each octet, switching to the next third octet at .255, and practice with examples like 192.168.0.0 to 192.168.2.255.

Learn subnetting by determining the network id, the IP of each subnet range, and why it is not assigned to devices; convert to binary, compute hosts, and map eight subnets.

Determine the broadcast address by converting the subnet to binary, calculating host counts, and identifying the final IP in each range to enable broadcast traffic to all devices.

Explore ftp transfers over ports 20 and 21, see why unencrypted ftp exposes sensitive files, and learn how encrypted protocols protect data with FileZilla and Wireshark.

Explore how SSH uses port 22 to provide a secure remote command line interface, a telnet alternative, demonstrated through Ubuntu setup, SSH server installation, and remote login.

Demonstrate how telnet over port 23 transmits an unencrypted remote login, exposing credentials captured in Wireshark, and show why this insecure protocol should be replaced by SSH.

Discover how DNS uses port 53 to translate fully qualified domain names like Wqpt.org into IP addresses, demonstrated via a real Wireshark DNS query and response.

Explore TFTP over UDP on port 69: a fast, file-only transfer method without browsing, intended for LAN use and booting networking devices with remote config files.

Explore how HTTP on port 80 transmits unencrypted data, demonstrate packet capture with Wireshark, and explain why HTTPS protects passwords on the public internet.

Explore how SNMP uses ports 161 and 162 to monitor and configure devices from a single server, compare versions 1/2 insecure with 3 secure, and perform a practical lab.

Explore how https, using port 443 and certificates, secures http traffic, and observe TLS encryption in real time.

Explore how smb uses port 445 for file and printer sharing, note smb v1/2 insecure and v3 secure, and see a host–guest lab with registry tweaks, firewall rules, and wireshark.

Explore how syslog uses port 514 to log activity locally and remotely, sending logs to a remote server in a Packet Tracer lab.

Demonstrate remote desktop protocol with a hands-on RDP session on port 3389, connecting a Windows host to a Windows virtual machine while observing traffic in Wireshark.

Explore the remaining ports and protocols for the Network+ exam, including smtp, smtp tls, pop3, imap, ldap, sql server, mysql, sqlnet, and sip, with notes on security and usage differences.

Demonstrate how ICMP, a layer three protocol, uses ping to detect devices on a network, with a hands-on lab showing ICMP traffic between two PCs and captured packets.

Compare TCP and UDP by examining their connection-oriented and connectionless natures, the transport layer’s segment versus datagram, and how Wireshark reveals sequence and acknowledgment fields.

Learn how gre tunnels enable IPv4 to traverse IPv6 networks and encrypt traffic with IPsec using ah and esp.