Skrpune’s Network+ Notes Based on the CBT Nuggets Network+ Video Series Author: Skrpune, ProProfs.com Table of Contents 1. Network Topologies Part 1 ............................................................................................................................................... 2 2. Network Topologies Part 2 ............................................................................................................................................... 3 3. Media Connectors & Cabling ............................................................................................................................................ 5 4. Network Devices & Components Part 1 ........................................................................................................................... 7 5. Network Devices & Components Part 2 ........................................................................................................................... 8 6. OSI Model ...................................................................................................................................................................... 10 7. Media Access Control .................................................................................................................................................... 11 8. IP Addressing ................................................................................................................................................................. 12 9. Network Layer Protocols ................................................................................................................................................ 13 10. TCP/IP Suite of Protocols & Services ........................................................................................................................... 15 11. TCP/UDP Protocols & Services ................................................................................................................................... 17 12. Additional Network Protocols & Services ..................................................................................................................... 18 13. WAN Technologies ...................................................................................................................................................... 20 14. Wireless Technologies ................................................................................................................................................. 22 15. Internet Access Technologies ...................................................................................................................................... 23 16. Remote Access Protocols & Services .......................................................................................................................... 24 17. Server Remote Connectivity & Configuration ............................................................................................................... 25 18. Security Protocols ........................................................................................................................................................ 26 19. Authentication Protocols ............................................................................................................................................... 28 20. Network Operating Systems ......................................................................................................................................... 30 21. Client Workstation Connectivity .................................................................................................................................... 31 22. Firewalls & Proxy Services ........................................................................................................................................... 33 23. VLANs .......................................................................................................................................................................... 35 24. Intranets & Extranets .................................................................................................................................................... 36 25. Anti-Virus Protection..................................................................................................................................................... 37 26. Fault Tolerance & Disaster Recovery ........................................................................................................................... 38 27. Troubleshooting Strategies .......................................................................................................................................... 40 28. Troubleshooting Utilities ............................................................................................................................................... 42 29. Physical Network Troubleshooting ............................................................................................................................... 43 30. Troubleshooting in Client/Server Environments ........................................................................................................... 44 1. Network Topologies – Part I Physical & Logical Topologies - Bus Topology – need terminator on each end of backbone o Physical Bus – physical arrangement in a series, not used much anymore o Logical Bus – i.e., hub in a physical star acting as the logical bus HUB PHYSICAL BUS LOGICAL BUS STAR TOPOLOGY - Star Topology o Physical Star – hub or switch at the center of the star o Logical Star – i.e., switch o Used in LAN / WAN Shared Ethernet bus if hub RING TOPOLOGY Switch does dynamic bridge • Maximize bandwidth via transparent braiding - Ring Topology o Physical Ring – physical closed loop o FDDI = both physical & logical ring o Token Ring = physical star, but logically a ring to pass token from node to node BUT each node must be attached to a hub/concentrator or a MSAU / MAU (multistation access unit) - MeshTopology o AKA, Frame Relay, ATM o Partial Mesh = used where need most redundancy or bandwidth ISP IEEE 802.2 / LLC - LLC = Logic Link Control MESH TOPOLOGY PARTIAL MESH o Maps to Data Link Layer 2 of OSI Model - What does LLC do?? OSI LAYERS o Manages data link connections, works with physical medium 7 APPLICATION o Addressing – reads MAC addresses 6 PRESENTATION o SAP’s – service access points 5 SESSION o Performs sequencing of data packets as they are moved around network 4 TRANSPORT o In a nutshell…provides basic networking between devices 3 NETWORK 2 DATA LINK 1 PHYSICAL IEEE 802.3 / ETHERNET (CSMA/CD) - Dominant LAN Technology = ~85%!!! - CSMA/CD = Carrier Sense Multiple Access/Collision Detection o FIRST, before sending, polls the channel to see if another node is transmitting o If not carrier is senses, then it transmits o If have a collision (i.e., 2 signals at once), will retry to send after a wait period o Puts limits to number of machines that can access network before collision increase & network gets too crowded - Collision Domain – logical network segment where data packets can collide with each other o NOTE: Switches create smaller collision domains than hubs & reduce congestion - 10BaseT / 10Mbps Ethernet developed by DEC + Intel + Xerox Ethernet Types / Speeds (Using CSMA/CD) - Half-Duplex Switching – cannot send & receive at same time 10 Mbps 10BaseT o I.e., walkie-talkie 100 Mbps Fast Ethernet - Full-Duplexed Switching – can send & receive; two-way transmission 1000 Mbps / 1 Gbps Gigabit Ethernet o I.e., telephone 10000 Mbps / 10 Gbps 10 Gigabit Ethernet - Advantages of using Ethernet o Easy to manage, maintain, implement o Flexible o Widely supported - Terminology / Components o DTE = Data Terminal Equipment – source or destination of data (laptop, PC, Server, Printer) o DCE = Data Communication Equipment – receive & forward frames on LAN network or to other LAN’s (Switch, Hub, Router, Modem) 2. Network Topologies – Part II CSMA/CA - CSMA/CA = Carrier Sense Multiple Access/Collision Avoidance o Node signals its intent to transmit – prevents other devices from sending, hence avoiding collision! o Used in Apple Talk / Local Talk o CA – algorithm by which channel time on ring is reserved to avoid collision Use RTS – Request To Send (“jam signal” of sorts) – wait to receive OK MSAU If another node tries to send a frame & sees a jam signal, will stop & retry later o CSMA/CA is principle median access method for 802.11 & WLAN’s too Need collision avoidance on 802.11 & WLAN’s because wireless uses half duplex radio signals 802.5 / TOKEN RING - Uses CSMA/CA - Created by IBM, still their main LAN technology - 802.5 – IEEE Standard, modeled after IBM’s token ring - Uses Physical Star, Logical Ring MSAU o All nodes attached to MSAU – MultiStation Access Unit) o MSAU performs the token passing inside the device - Speeds of 4.16 Mbps & 16 Mbps - Baseband transmission – uses full transmission range for one signal (as opposed to Broadband/DSL/Cable) o Other Baseband Transmissions HSTR (High Speed Token Ring - 100 Mbps, 16 Mbps, 4 Mbps); 802.5t, 802.5u, 802.5v, etc. - Token Passing Access Method - o Move a small frame (00110110), broken up by fields, etc. o If node gets a token & had no data to send, just sends the token along to next device on logical ring o If node has data to send, i.e. to printer, will grab the frame & alter a 0 or 1 & will append the info it wants to transmit (adds its own stuff) ***While