1. CN1260 Client Operating System Kemtis Kunanuraksapong MSIS with Distinction MCT, MCITP, MCTS, MCDST, MCP, A+

2. Agenda Chapter 2: Resolving IP Connectivity Issues Quiz Exercise

3. Connecting to a Network Ethernet ▫Unshielded twisted-pair (UTP) cabling ▫RJ-45 connectors ▫100 Mb/s or 1 Gb/s connections for Ethernet When there is a connectivity issue: ▫Check the cable ▫Look at the indicator lights on the NIC, switch ▫On the switch or hub, make sure that the switch or hub has power and is turned on.

4. TCP/IP Protocol Suite Transmission Control Protocol/Internet Protocol Subnet ▫Subdividing TCP/IP networks into smaller groupings Subnet mask ▫Used to identify which network the TCP/IP host resides on Default gateway ▫Allows a host to communicate with devices that reside on a remote network or location

5. Host and IP addresses A host ▫Any device that connects directly to a network ▫Computers, network printers, routers, layer 3 switches, managed switches, and any other device that has a network card or interface Internet Protocol (IP) address ▫A logical address and numerical label that is assigned to a device that is connected to a computer network

6. IP Address IPv4 is The most commonly used version used today Based on 32-bits (four bytes, or octets) ▫2 32 (4,294,967,296) possible addresses IPv4 addresses are commonly represented using what is called dotted-decimal notation: ▫10.27.3.1 ▫192.1.120.84 ▫192.5.18.102 IPv6 addresses, which are based on 128-bit addresses. ▫Since each bit doubles the number of available addresses, the 128-bit addresses allow up to 3.403 × 10 38 addresses

7. Classful Addressing Each network class had a different maximum number of nodes ▫The first one to four bits identified the network class, and the remaining bits comprised the network and host address fields ▫Class A ▫Class B ▫Class C  See Table 2-1 on Page 32

8. Subnet Mask Logical partitioning of an organization’s network address range into smaller blocks Network Address (Enterprise/corporation): ▫16.52.0.0/16 Site 1 has network address of: ▫16.52.1.0/24 Site 2 has network address of: ▫16.52.2.0/24

9. Classless Inter-Domain Routing (CIDR) The number of masked bits is specified with the CIDR notation Variable-length subnet masking (VLSM) Example: ▫10.0.0.0/10  10 bits masked  22 bits for host numbering

10. Network Address Translation (NAT) Hosts using private network addresses can communicate with public networks only by using network address translation (NAT) Enables routing by mapping their private network address to a different, routable network address.

11. Private Addresses Reserved addresses not allocated to any specific organization Not routable on the Internet, you must use a NAT gateway or proxy server to convert between private and public addresses ▫10.0.0.0 – 10.255.255.255 ▫172.16.0.0 – 172.31.255.255 ▫192.168.0.0 – 192.168.255.255

12. IPv6 Addressing IPv6 addresses are 128 bits in length and expressed in hexadecimal notation ▫2001:0db8:85a3:08d3:13 ▫19:8a2e:0370:7334 If an IPv6 address contains a series of sequential zeroes, the address can be shortened ▫2001:0000:0000:0000:0000:0000:0000:7334 ▫2001:0:0:0:0:0:0:7334 ▫2001::7334

13. IPv6 Addressing First 64 bits is the network address ▫First 48 bits is network prefix ▫Next 16 bits are used for subnetting Second 64 bits is the host address ▫Generated by MAC address

14. IPv6 Addressing Unicast addressing can be divided into: ▫Global unicast address  Routable on the IPv6 portion of the Internet ▫Link-local addresses  Private non-routable addresses (LAN only) ▫Unique local addresses  Meant for private addressing, with the addition of being unique, so that joining two subnets does not cause address collisions.

15. Default Gateway A default gateway is a device, usually a router, which connects the local network to other networks When you need to communicate with a host on another subnet, you forward all packets to the default gateway

16. Name Resolution Form of naming service that translate logical names, which are easier to remember, to those logical addresses

17. HOST and LHMOST Files Hosts ▫Used with domain/host names associated with DNS Lmhost ▫Used with NetBIOS/Computer names associated with WINS files In Windows, both of these files are located in the C:\Windows\system32\drivers\etc folder See Figure 2-2 on Page 36

18. Domain Name System (DNS) A hierarchical client/server-based distributed database management systems that translates domain/host names to an IP address Use FQDN to translate hostname to IP

19. Windows Internet Name Service (WINS) WINS translates from NetBIOS (computer name) to specify a network resource

20. Network and Sharing Center Provides real-time status information about your network. It can be used to configure and manage your network connections It can also be used to help troubleshoot network connectivity problems See Figure 2-3 on Page 38

21. Managing Network Discovery and Sharing Services The Network and Sharing Center also allows you to configure certain network services such as network discovery and sharing. These settings include: ▫Network discovery ▫File and printer sharing ▫Public folder sharing ▫Media streaming ▫Password protected sharing

22. Ports A host uses ports to identify which packets belong to a network service or program. ▫65,535 TCP ports ▫65,535 UDP ports Common ports: ▫DNS: TCP/UDP port 53 ▫FTP: TCP port 20 and 21 ▫HTTP: TCP port 80 ▫HTTPS: TCP port 443 ▫SMTP: TCP/UDP port 25 ▫Telnet: TCP/UDP port 23

23. Troubleshooting IP Network Problems If the problem still exists, you can also use the following command-line tools: ▫Ipconfig (/all, /flushdns, /renew) ▫ping ▫tracert ▫pathping ▫netstat ▫telnet ▫nslookup

24. Assignment Submit these before class over on Thursday ▫Fill in the blank ▫Multiple Choice ▫True / False Submit these before class start on Monday ▫Case scenarios 2-1 ▫Lab 2