1 / 15

Networking Fundamentals & Configurations for Peer Devices

Explore the basics of networking, from wired to wireless configurations. Understand different network setups such as bus and star networks, and learn about interconnecting devices using repeaters, bridges, switches, and routers. Delve into routing messages based on IP addresses, DNS translation, reverse lookup, and DNS attacks.

lenora
Télécharger la présentation

Networking Fundamentals & Configurations for Peer Devices

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. CSE111: Great Ideas in Computer Science Dr. Carl Alphonce 219 Bell Hall Office hours: M-F 11:00-11:50 645-4739 alphonce@buffalo.edu

  2. cell phones off (please)

  3. Announcements • Exam 1 handback. • HW3 due March 5. • Second exam is March 17 (week after spring break).

  4. Today’s Agenda • Networking

  5. Networking • What sorts of networks do we use? • Wired networks (in the labs) • Wireless (WIFI) networks (right now?) • Wireless cell phone networks • Wireless bluetooth (“personal area networks”)

  6. Configurations • Bus network • Devices connected to a common communications channel • Devices are peers • Ex. Typical wired network • Star network • Devices connected to a central machine • Devices communicate only via central machine • Ex. Typical wifi network (access point)

  7. Interconnecting networks • Repeater • Propagate signals between networks • Bridge • Propagate some signals between networks • Switch • Bridge with multiple connections • Router • Interface networks with different characteristics (e.g. ethernet bus to WiFi access point)

  8. Routing messages • Each device has an address on the network (IP address) • Messages are routed based on destination IP address. • IPv4: 32 bit address (4.3 X 109) • styx.cse.buffalo.edu (128.205.36.7) • 10000000.11001101.00100100.00000111 • IPv6: 128 bit address (3.4 X 1038)

  9. Domain Name System (DNS) • Translate from mnemonic form styx.cse.buffalo.edu • to IP address 128.205.36.7 (dotted decimal notation) • Determine DNS server • Windows • run ‘ifconfig /all’ at cmd prompt • Mac • Network preferences window • Look at /etc/resolv.conf file

  10. Reverse lookup:whois • Try: whois 128.205.36.7 whois 142.103.7.7

  11. 127.0.0.1 • localhost, or “home” • E.g. own machine provides service

  12. HumorImage from: www.thinkgeek.com

  13. HumorImage from: www.thinkgeek.com

  14. DNS hierarchy • Root servers • Caching domain servers • Applications can cache as well

  15. DNS attacks • Denial-of-service • http://royal.pingdom.com/2009/01/26/dns-attack-slowed-down-hundreds-of-thousands-of-websites/ • DNS poisoning • You look my www.mybank.xyz • You go to web site of www.crooks.xyz • They put up page that looks like your bank’s page – and steal your banking log-on information.

More Related