1. Network Operating Systems versus Operating Systems Computer Networks

2. Network Operating System (NOS) NOS have dedicated servers Client server networks Servers provide a variety of services for other computers on the network

3. Operating System (OS) Networks that don’t use NOS are peer-to- peer networks Consists of client computers Client computers can also perform specific server functions if they use special server software

4. File Sharing Peer-to-Peer (P2P) Networked computers in a peer-to-peer LAN network can share: ◦Hard drives ◦File folders ◦Internet access ◦Network resources such as printers and fax machines ◦Examples, household, small office, students

5. Sharing on the Internet P2P Global Sharing on the web requires a special software client like Napster, BitTorrent, etc. Everything in the shared file is shared with other users You don't see the names of users on the web

6. Security Methods (P2P) Workgroups ◦Share files with others in the same workgroup ◦Password protected Passwords ◦File security is the responsibility of the end user ◦Can set access rights to specific files and folders Permissions – Read only, see but not edit – Write only/change, read, edit or add – Read and Write or Full access (edit or delete)

7. Client Server/Dedicated Server Has at least one computer that works only as a server Run on a network operating system, such as Windows Server 2003 or 2008, linux or Unix

8. Types of servers Web (HTTP) server Email server Proxy server (controls the entrance to a LAN from the Internet and responsible for controlling IP addresses) File server Application server (software programs)

9. Roaming Authentication Log into any machine on the LAN and access same files and system settings, protected with a password

10. Network Address Translation Proxy server is LAN gateway to Internet Protects the internal LAN by using two different IP addresses: a public address that the Internet can see and a private one used on the LAN The ISP (Internet Service Provider) provides the IP address(es) for the Internet Proxy Server (using DHCP) assigns a different IP address for each computer on the LAN

11. Domain Name System (DNS) On the Internet DNS stores the names for websites (google.com) and the web addresses that are linked to them Translates the domain name into an IP address and finds the web host that stores the files

12. Windows Internet Naming System Within a LAN, the comparable naming service is WINS Names individual computer using NetBIOS: example “Laura’s Computer”

13. Mapping a Shared Drive In a peer-to-peer network, if someone shuts his computer down, his files will no longer be available for others. One benefit of using a client/server network is that files will always be available so long as the server is running. When working off a server, you can also mount a shared network drive, so that it shows up under My Computer as if it were on the local machine.

14. IP Config Command Using Command Prompt IP Congig will find the computer’s IP address It will also show subnet masks that are assigned to different departments or sections