-
Remote Connectivity–Advanced IP Networking–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA Network+ (N10-007) NETWORK-PLUS Certification Prep Course Notes
Remote Connectivity Telephony Technologies Original telephone systems used frequency division multiplexing; today they use time division multiplexing. T1 = 24 DSOs = runs at 1.544 (~1.5) Mbps T3 = 28 DS1s = runs at 44.736 (~45) Mbps [DS1–Digital Signal 1] E1 and E3 are European carriers 64 Kbps Frequency Division Multiplexing Time Division Multiplexing A DS0 can carry 64 kilobits per second! DS1 (digital signal 1)–24 DS0 signals all going down the same wire. this is not Frequency, but Time Division Multiplexing, it uses block & frames, not frequencies. DS1 is just a signal type that runs on something called “T1”. “T1” is a specific type of cabling system. T1…
-
IPv6–Advanced IP Networking–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA Network+ (N10-007) NETWORK-PLUS Certification Prep Course Notes
IPv6 Intro To IPv6 IPv6 are 128-bits, have a MUCH larger address space than IPv4. IPv6 addresses have 8 segments separated by 7 colons. IPv6 allows data to move much faster through the internet. NDP (Neighbor Discovery Protocol) IPv6 Addressing IPv6 addresses can be shortened by removing leading zeros, but be familiar with the rules. IPv6 addresses have 2 IP addresses: a link-local address & an Internet address. The 2nd part of the IPv6 address using EUI-64 is generated from the MAC address. Link-local address is automatically generated; Internet address is provided by local router. Link-local address starts fe80:0000:0000:0000 (1st four sets) Smallest IPv6 address you can have will be…
-
Advanced IP Networking–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA Network+ (N10-007) NETWORK-PLUS Certification Prep Course Notes
Advanced IP Networking Advanced Networking Devices Understand IP Tunneling Very few Internet protocols are encrypted! Tunnels can encapsulate unencrypted protocols to create encrypted communication channels. Tunnels are often used with remote access connections. A tunnel starts by making an encrypted connection between 2 computers. Tunnels are used to provide encryption where there normally isn’t any. They are used to encrypt unencrypted protocols. VPNs (Virtual Private Networks) A VPN creates a secure tunnel so a remote machine or network can be part of a local network. A ‘client-to-client‘ VPN connects a remote computer to a local network. A ‘site-to-site‘ VPN connects distant networks into a single network. Remote Connections Challenges LAN…
-
Securing TCP/IP–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA Network+ (N10-007) NETWORK-PLUS Certification Prep Course Notes
Securing TCP/IP Making TCP/IP Secure Security can be broken into 3 areas: The “CIA of Security”: Confidentiality, Integrity, & Availability Confidentiality can be addressed through encryption. Confidentiality & integrity must be balanced with availability. Encryption Non-repudiation Availability Authorization & Authentication–big part of CIA Symmetric Encryption Cleartext is any unencrypted data. Algorithms use keys to encrypt cleartext into cyphertext. An algorithm that uses the same key to encrypt & decrypt is symmetric encryption. Caesar Cipher–“old goldie”–like a secret decoder ring. Algorithms–the process that “stirs up” the values. Note: All algorithms work this way…we’re going to have cleartext, cyphertext, some form of algorithm, & a key. Key Cyphertext Asymmetric Encryption (created by…
-
Network Naming–Making TCP/IP Work–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA Network+ (N10-007) NETWORK-PLUS Certification Prep Course Notes
Network Naming Understand DNS (Notes: DNS & ARP are different protocols! DNS maps friendly names to IP addresses. ARP maps IP addresses to MAC addresses.) DNS resolves FQDNs to IP addersses. DNS (Domain Name System!) .com & .edu are examples of top-level domains (TLDs). www.example.com The Individual Host Name is the ‘www.’ ‘www.’ will take you to a Web domain server. ‘ftp.’ will take you to an FTP server. ‘mail.’ will take you to a mail server. The name of the individual host name can be anything but these are the conventions commonly used. Note: ‘ipconfig /all’ –> DNS settings Computers & DNS Servers cache address information. Apply DNS CNAME…
-
TCP/IP Applications–Making TCP/IP Work–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA Network+ (N10-007) NETWORK-PLUS Certification Prep Course Notes
TCP/IP Applications TCP and UDP Ethernet frames are used by switches & routers. PDU (Protocol Data Units) are the information used by the different protocols provided in frame segments. TCP is connection-oriented, 2-way communication initiated by a 3-way handshake process (syn, syn-ack, ack). UDP is connectionless-oriented protocol, has low overhead with one-way communication. ICMP & IGMP (Note: Ping uses ICMP.) ICMP (Internet Control Message Protocol) works at the Internet (2) Layer in the TCP/IP model, & the network (3) layer in the OSI model. IGMP (Internet Group Management Program) provides multicasting support. Multicast addresses always start with “224”. ex: 224.x.x.x Handy Tools Both ‘tracert’ (Windows), and ‘traceroute’ (Linux) commands display…
-
Routing–The World of TCP/IP–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA Network+ (N10-007) NETWORK-PLUS Certification Prep Course Notes
Routing Introducing Routers Routers only care about destinations. Routers interconnect Network IDs. Routers can use any network medium! Routes are not tied to Ethernet; They can have DSL, Fiber-Optic connections, etc. All routers have a routing table! A routing table will have at least 4 columns: Address, Subnet, Gateway, & Interface. A router is a box that connects network IDs. Routers filter & forward based on IP address (Remember, “switches” filter & forward based on MAC address.) Default Routes have “Address” and “Subnet” data of “0.0.0.0” The primary job of a router is to connect networks with different network IDs. Understanding Ports Understanding Ports Port numbers identify the sending &…
-
TCP/IP Basics–The World of TCP/IP–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA Network+ (N10-007) NETWORK-PLUS Certification Prep Course Notes
TCP/IP BASICS Intro to IP Addressing & Binary Each computer on a TCP/IP network must have a unique IP address. IPv4 addresses are written as four octets, such as: 192.168.4.12 Each octet represents a binary string; 192, for example, is represented by 11000000 Dotted decimal notation–shorthand used to represent the 32 1’s & 0’s. 28 (256) combinations Each octet is valued between 0 and 255. Converting from binary to dotted decimal: Intro to ARP APR (Address Resolution Protocol) resolves IP addresses. ARP is what a computer uses when it knows the IP address, but needs the MAC address. Type ‘arp -a’ to see the ARP cache (shows a list of…
-
Installing a Physical Network–The Physical Network–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA Network+ (N10-007) NETWORK-PLUS Certification Prep Course Notes
Installing a Physical Network Intro to Structured Cabling Structured cabling defines how we install cabling (i.e.–cable organization). Structured cabling systems will have: 1). Telecommunication closet/equipment room. This room will contain all switches & centralized stuff that runs out via, 2). Horizontal Runs to individual 3). workstations/work areas. TIA standards specify wiring standards for structured cabling. Patch panels terminate one end of horizontal runs. Patch cables connect switches to patch panels & computers to wall outlets. Terminating Structured Cabling RJ-45 crimps are used only on patch cables. Horizontal runs are terminated with 110-punchdowns. Note: Horizontal runs are punched down to the back of a patch panel on one end, and on…
-
Modern Ethernet–The Physical Network–NETWORKING, SECURITY, & MORE ESSENTIALS—CompTIA Network+ (N10-007) NETWORK-PLUS Certification Prep Course Notes
Modern Ethernet 100Base-T Full-duplex mode allows both sides of a conversation to occur at the same time. Half-duplex, you can “talk” or “listen” but not at the same time. 100BaseT (aka 100BaseTX) runs at 100 Mbps up to 100 meters. 100BaseFX, a fiber solution, runs at 100 Mbps up to 2 kilometers. Connecting Switches (Note: Connecting switches in a tree structure is common when networks are larger & more spread out, into clusters.) Straight-through cables have identical ends, such as 568B. Crossover cables have different ends–568A and 568B. Connect switches directly with crossover cables. Gigabit Ethernet & 10-Gigabit Ethernet Know your 1000Base types: names, distances, node numbers, etc. Know your…