1 / 21

Linux Networking

Linux Networking. CIS230.0325. Why Linux/Unix?. Configurability Customizable System to satisfy unique needs. Scalability Able to serve an increasing number of users with out down time. Stability Exceptional design to avoid crashes. Daemon & HTTPD. Daemon Linux Program

Download Presentation

Linux Networking

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Linux Networking CIS230.0325

  2. Why Linux/Unix? • Configurability • Customizable System to satisfy unique needs. • Scalability • Able to serve an increasing number of users with out down time. • Stability • Exceptional design to avoid crashes

  3. Daemon & HTTPD • Daemon • Linux Program • Runs in the background • Starts up and shuts down with the system • Httpd • D for daemon • Runs in the background • Answers server request from clients

  4. Inetd & TCP Wrappers • Inetd • Links ports to associated server domain • Runs appropriate programs that are requested • TCP Wrappers • Grants or denies Server Request • Logs network use • Date • Time • Service requested • Clients name • Address

  5. File Sharing • FTP (file transfer protocol) • NFS (network file system) • To access shared file: • file must be listed in the NFS server host file. • User must know location • Mount file using mount command (line prompt) • Able to view mounted file like directory

  6. Network File System • NFS allows users to view/share files in Unix/Linux • Allows users to access their files from virtually any computer • Virtual file system • NFS Request are stateless • Repeats client request during system crash • During reboot, server would then answer request like the system crash never occurred • Knfsd – Kernel network file system daemon • Runs in Kernel mode • Uses NFS tools to improve response time for clients

  7. Server Message Block • SMB is a client/server protocol • Application and presentation level protocol • Runs on transport and network protocols • In charge of • File sharing • Printing • Logins

  8. Samba/Share • Samba is server for sharing, printing, and login services • Share allows users in a SMB to share resources in network • Two components of samba: • Smbd: responsible for file and print services and executes users verifications • Nmbd: applies name resolution and browsing

  9. SWAT • Samba Web Administration Tool allows system administrator: • Change Samba configuration • Select shares • Set verification requirements like user name and password

  10. Postscript/Ghostscript • Postscript: • Is used to optimize printing graphics and text • Provides convenient language for printing with out reference to any device features like printer resolution • Ghostscript converts postscript documents to raster • ( composed of pixels and dot) image. Because inkjet printers are not compatible with postscript Postscript is the Linux/Unix page description language.

  11. LPD/CUPS LPD (line printer daemon) CUPS (common Unix printing system) • Linux Print Spooler • Starts when computer boots • Waits for print request from clients • Holds prints jobs until printer is ready • Prints the next file on the list • Allows computer to act as a print server • Accept print jobs from clients • Process and sends to appropriate printer • Consist of spooler, scheduler and filter system • Converts print data to a format that the printer understands

  12. Internet Printing Protocol • IPP manages print jobs and queues • Runs on HTTP and allows bidirectional communication between server and client • Allows search for available printers in the network • Verifies which client can access server host • Stores logs and provides accounting capability • Offers compatibility with older LPD-style clients

  13. Apache • Open source web server used by Linux/Unix • Powers more then half the web sites around the world (ex. hotmail, yahoo) • Displays and serves HTML pages hosted on a server to a client browser

  14. KHTTPD • Kernel mode Linux daemon that provides a web service • Able to run on Apache • Kernel mode speeds up serving of static pages • Errors are able to bring down an entire system • User based process are more stable

  15. Apache pre-forking • Creates multiple child processes to handle HTTP request • Parents process checks to see child process are working properly and coordinates everything • As more HTTP request are made, more child process are created to process them • When HTTP goes idle, the parent would kill child processes to free up resource • If child process were to crash, the parent and other child would not be effected • This process make apache very reliable

  16. Apache - Modular Architecture • Provides basic http functionality and other modules to provide additional functionality • Supports dynamic shared object that permit loading of external modules at a run time • Provides Application Programming Interface (APT) • Apache is fully customizable to the administrator or programer • Portable run-time layer provides • File input/output • Network input/output • Own memory management routines

  17. Apache Filter • Accepts input from the standard input device • modifies data and sends the results to the standard output device • Used internally to process internal functions • When receiving a request, it delegates the request to a single content handler module that sends the data back to the client

  18. Clusters & Beowulf Clusters • Consist of multiple computers, each with its own O.S • Works with high speed network • Goals • High performance • High availability • Load balance • Scalability • Manageability Beowulf Clusters • Tightly connected network computers dedicated to the solution of a single problem • Links multiple inexpensive computers to achieve the performance of a super computer • Low priced

  19. Single System Image • A SSI is a comprised of multiple resources such as • Networks • Distributed Databases • Or Servers • To act as a single unified powerful resource • Linked to form peer-to-peer network • Does not share client-server relationship • Managed by the operating system’s kernel • Unlike Beowulf clusters • Does not need to be modified to use MPI • Regular programs can run without modification • Doesn’t need to be cluster aware to have benefits

  20. Cryptic line commands vs. User-friendly interface

More Related