Professor Dr. Dieter Steinmann

Präsentation zum Thema: "Professor Dr. Dieter Steinmann"—  Präsentation transkript:

1 Professor Dr. Dieter Steinmann
Vorlesungen Grundlagen Wirtschaftsinformatik Fachhochschule Trier Internet-technische Grundlagen Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

2 Internet (Quelle: www.caida.org)
Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

3 Professor Dr. Dieter Steinmann
What ist the Internet? ... a network of networks Professor Dr. Dieter Steinmann

4 Professor Dr. Dieter Steinmann
Internet Strukturen DFN T-Online Nacamar # Gateway # Netzübergang Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

5 Provider-Backbone (Nacamar 1999)
Europe Germany Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

6 Professor Dr. Dieter Steinmann
Rechneradressen Domain: fh-trier.de Subnet-Bereich: XX XX XX Netzwerk-Maske: madrid madrid.fh-trier.de Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

7 Mapping von Domain-Name und Adresse
Angabe des DNS und des Gateways auf jedem Rechner Eintrag des übergeordneten DNS auf lokalem DNS Domain Name Server (DNS) madrid BWPC7 Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

8 Automatische Vergabe von IP-Adressen
Provider Vergabe von zufälligen Internet-Adressen bei Verbindung (Protokoll user, Zeit, Adresse) Adress-Pool ... Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

9 Infrastrukturen Kopplung Netzwerke
Internet-Nutzer Provider Gateway ISDN Spez. Datenleitung Satellitennetzwerke ... Provider- Backbone Firewall Hard- und/oder Software zum Schutz von Daten, Anwendungen, Kommunikation Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

10 Auflösung von Host-Names
root domain top-level-domains .au ... .de .uk .com .edu .org .gov .mil Each domain has its own dns who is responsible for the sub-domains Diffrent levels: root-level-domain, top-level-domain, sub—level-domain, ... Host Caching: each adress-resolution is stored some time fh-trier.de ... netbrain.de microsoft.com netscape.com madrid.fh-trier.de pop.fh-trier.de pop.fh-trier.de Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

11 TCP/IP IPv4-Adressierung
Internet-Adresse: Netzwerk-Maske Subnet-Bereich Host-Bereich Professor Dr. Dieter Steinmann

12 Übersicht Adressenvergabe
Numerische Adressen Domain Names (Verzeichnis) Top Level (.com, .org, .int, .edu) Country Code Top-Level Domains (CCTLD) DE: Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

13 Adressklassen in TCP/IP
A B C D Professor Dr. Dieter Steinmann

14 Schwächen der IPv4-Adressierung
+ Adressraum beschränkt + Keine Sicherheitsmassnahmen (Paketebene) + Nicht für Multimediadaten geeignet + keine Authentifizierung + Authentifizierung und Sicherheit über SSL, TSL auf dem Modell aufsetzend Professor Dr. Dieter Steinmann

15 Vorteile IPv6- oder IPng-Adressierung
+ Adressraum vergrößert (2**128 Adressen) + Integration einer Vielzahl von Geräte-Steuerungen „everyday devices as ligthing equipment, electrical power“ + Adressaufteilung in hierarchische Blöcke + Providerbasierte Adressen Provider-Klassifizierung + lokale Adressen innerhalb eines Unternehmens + unicats, multicast und anycast-Adressen Professor Dr. Dieter Steinmann

16 Gegenüberstellung IPv4- und IPv6-Adressen
32 bit Dezimaldarstellung 4 Oktetts (8-bit-Gruppen) Adressraum: 2**24 Adressen Routing Tables IPv6 128 bit Hexadezimaldarstellung F0D1:AA57:0:0:0:0:0:3F5A 8 Quartetts Adressraum: 2**128 Adressen Hierarchische Blöcke Providerbasierte Adressen Professor Dr. Dieter Steinmann

17 Mit IPv6 sind pro Quadratmeter der Erdoberfläche
Adressen verfügbar (15% davon sind heute genutzt) (Erdoberfläche: Quadratmeter) Quelle: Hinden, Robert M., Professor Dr. Dieter Steinmann

18 Organisationen die das Internet prägen
Internet Architecture Board, Internet Engineering Task Force, Internet Engineering Steering Group, Internet Research Task Force, Internet Assigned Numbers Authority, Internet Corporation for Assigned Names and Numbers, Entstehung aus dem ARPA/DARPA-Netz Federführung US-Regierung Actual National Science Foundation, TCP/IP-Referenznmodell neben ISO/OSI-Referenzmodell Wichtig für Internet-Benutzer Adressierung Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

19 Adressierung Name und numerische Adresse
Symbolischer Name madrid.fh-trier.de Numerische Adresse Vergabe durch: IANA und ICANN Internet Assigned Numbers Authority Internet Corporation for Assigned Names and Numbers Professor Dr. Dieter Steinmann

20 Übersicht Adressenvergabe
Numerische Adressen Domain Names (Verzeichnis) Top Level (.com, .org, .int, .edu) Country Code Top-Level Domains (CCTLD) DE: Professor Dr. Dieter Steinmann

21 Professor Dr. Dieter Steinmann
Standards and Drafts Internet Architecture Board, IAB, [ Internet Engineering Task Force, IETF [ Requests for Comments (RFC) [ Internet Drafts [ Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

22 Begriffe Internet – http, https
http, hypertext transfer protocol RFC 2616 (HTTP/1.1), 2617(Authentication) http transfer of data + text + graphics + sound, video and other multimedia http files contain references to other files wap, wireless application protocol DNS Host Names Host names are organized based on the tree structure of DNS. The individual node name comes first, followed by the domain where it resides, followed by the domain in which the domain resides, and so on, with each level separated by a dot. So, for example, when we see the host name host1.engineering.cisco.com, we know that the node host1 is in the engineering subdomain of the cisco domain, which in turn is in the com domain, which is under the root domain of the Internet. DNS Delegation Each domain has its own name server, a server which contains the host name information about the hosts and sub-domains within its domain. The cisco.com domain, for example, has a name server that stores address information about all of the hosts and subdomains in the cisco.com domain. However, authority for a subdomain, such as engineering.cisco.com, can be passed to a name server that has authority for that subdomain. When a name resolution request comes to the cisco.com name server, it just passes the request off to the engineering.cisco.com name server. In this way, DNS is truly distributed across the Internet, with each domain maintaining only the information that is pertinent to that domain. Name Resolution Because DNS is distributed across domains, when a name server receives a request for name resolution for a host that is outside of its domain, it may not have address information for that host. Because DNS is hierarchical, it does not need that information, the name server just needs to know how to access the root name server. It forwards the name resolution request to the root name server, which then delegates the request to the appropriate domain beneath it, and this process continues until a name server which has address information for the host is reached, and the information is retrieved. Caching In order to reduce the length of time of name resolution, and to reduce traffic on the network, important concept of DNS is that of caching. Whenever a name server receives address information for another host or domain, it stores that information for a specified period of time. That way, if another name resolution request for that host or domain is received, the name server has the address information ready, and does not need to send another inquiry across the Internet. The length of time address information is stored on the name server is determined by the Time-To-Live (TTL) value entered in the domain Start of Authority (SOA) resource record. Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

23 Professor Dr. Dieter Steinmann
Beispiel html-1 <html> <style> </style> <head>Überschrift</head> <body> <p> Paragraphentext 1 </p> <p> Paragraphentext 2 </p> <p> Paragraphentext 3 </p> <p> Paragraphentext 4 </p> <p> Paragraphentext 5 </p> <p> Paragraphentext 6 </p> </body> </html> Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

24 Professor Dr. Dieter Steinmann
Beispiel html-2 <html> <style> </style> <head>Überschrift</head> <body> <p> Paragraphentext 1 </p> <table border=1 cellspacing=0 cellpadding=0> <tr><td> width=307 valign=top <p> Zellentext </p> </td> <tr> </table> </body> </html> Tabel le Tabel le Spalte Zeile Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

25 Begriffe Internet - Sicherheit
Basistechnologien + secure socket layer (ssl), transport layer security (tls) + secure hypertext transport protocol (https) Verschlüsselung + Certficate + Certification Authority Signature Homebanking: SET, HBCI, PIN/TAN pgp, MIME, Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

26 Wireless Applications
SMS WAP sms - short message system wap - wireless application protocol Professor Dr. Dieter Steinmann

27 wireless application protocol (wap)
Internet Access # # www # newsgroups # internet relay chat (irc) Communication protocol for wireless devices cellular phones Conceived by Ericsson, Motorola, Nokia and Unwired Planet (now Phone.com) Four Layers # Wireless Application Environment (WAE) # Wireless Session Layer (WSL) # Wireless Transport Layer Security (WTLS) # Wireless Transport Layer (WTP) Professor Dr. Dieter Steinmann Prof. Dr. Dieter Steinmann

28 Professor Dr. Dieter Steinmann
Zusammenfassung Weitere flächendeckende Verbreitung des Internets mit hoher Bandbreite Internationale Standardisierungsgremien, Organisationen, die das Internet verwalten Sicherheitstechnologien werden immer ausgereifter (siehe Vorlesung Datensicherheit) Veränderung der Zugangsgewohnheiten durch kleine intelligente Geräte mit relativ großem Display (Monitor-Brille als Ausgabemedium) Adresseraum reicht mit IPv6 aus, um alle Geräte mit einer Adresse zu versehen „Bedrohung: alle Menschen erhalten bei Ihrer Geburt eine Internet-Adresse und sind so weltweit eindeutig zuordenbar“ Professor Dr. Dieter Steinmann