Hypertext Transfer Protocol (HTTP)

See http://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol

Please watch carefully the video on http://www.youtube.com/watch?v=kGOpY2J31pI. Besides documentation please answer the following questions:

• Which request methods are used at HTTP? Which method do you use for which purpose?
• Do GET requests modify data on the server?
• When is a GET request transmitted to a server?
• What is the difference between GET and POST requests?
• When you log in to a server, which method is usually used?
• Describe the other request methods in brief.
• Look at http://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol#Example_session. What is sent to a server if you don't specify a path?
• During the practical classes please analyze a HTTP session with Wireshark. Please document also the TCP 3-way handshake procedure at startup.

1. 
   
1. OPTIONS (Checkt die Methoden die ein Server unterstützt)
2. PUT (Speichert eine URL)
3. DELETE (löscht die Resourcen)
4. TRACE (gibt an ob sich etwas im Server verändert wurde)
5. CONNECT (Konvertiert das TCP/IP-Signal in den HTTP proxy um)
2. GET sollte nur von einem Server lesen und nicht weitere Funktionen haben, also nein.
3. Wenn der HEAD eines Requests ausgeführt wird um den Body zu empafangen
4. GET ist da um zu lesen, POST is da um zu schreiben
5. POST

IPv6 ND in PacketTracer and Wireshark

In this lab you will find out more about IPv6 ND with PacketTracer and Wireshark. Please document as much as possible in your blog.

• View all messages from the school network regarding IPv6 ND.
• Ping eacher other and protocol the IPv6 ND messages.

Konfigurieren der IPv6-Adressen:
-static
-DHCPv6
-Autoconfig

Autoconfig
Netzwerkteil muss stimmen!
Routeradvertisment wird ausgeschickt mit dem Netzwerkteil, via Multicast mit der Gruppe all notes (alle Knoten). 
Hostteil: 1. EUI 64 (1en 24 Bit der MAC adresse:FFFE:24 weiter Bit MAC (meistens Linux)
               2. Random mit Zufallszahl

Via Multicast wird überprüft ob jemand schon die IP-Adresse hat. Wenn keine Antwort zurückkommt funktioniert es.

Wireshark: 

In Zeile 4 bekommt er den Router Advertisment also den Netzteil (alle 30 sek)
In Zeile 24,25 wird die angepingte Macadresse ausgetauscht.
Darunter erfolgt der Pingbefehl.

IPv6 Neighbor Discovery

There is no ARP in IPv6.  Instead it uses ICMPv6 for Neighbor Discovery via the Neighbor Discovery Protocol. Please watch the following video and document everything in your blog.

http://www.youtube.com/watch?v=6rXn7dcj4xA

Answer the following questions:

• What is the "host autoconfiguration"?
• Which ICMPv6 types are used for neighbor discovery?
• What is a "tentative address" and what is it used for?
• Which kind of IPv6-address is "FF02::1"?
• Which steps are necessary before two hosts can exchange messages? 

Neighbor dicovery:

It's a Protocol in IPv6. It's responsible for the exchange of link-local messages.
It's also being used to determine IPv6-addresses into Link-Layer-Addresses (MAC).

1. eine LinkLocal Adresse wird ohne DHCP errichtet.
2. 135 und 136
3. Ist eine LinkLocal Adresse die einzigartig ist (meistens von Mac Adresse abhängig). Sie wird zur Kommunikation ohne Autorouting verwendet (z.B.: zwischen 2 Hosts)
4. Multicast

IPv6 - Adressierung

In dieser Einheit geht es um die Adressierung bei IPv6. Sehen Sie sich das Video unter https://www.youtube.com/watch?v=RkhK-JliNUY an und lösen Sie folgende Aufgaben:

• Erstellen Sie eine übersichtliche Dokumentation in Ihrem Blog.
• Was bedeutet dotted decimal notation bei IPv4?  
• Wieviele Hexziffern braucht man für die Darstellung einer 128 bit IPv6-Adresse?
• Warum kann man nicht zweimal :: in einer IPv6-Adresse haben?
• Was passiert mit in den 16 bit langen Hexzahlen?
• Wie wird bei Cisco-Routern eine IPv6-Adresse bei einem Interface konfiguriert?
• Was sind Anycast-Adressen bei IPv6?
• Was sind die Aufgabe von Link-Local-Addreses?
• Wie funktioniert Stateless Autoconfiguration?

1. Unterteilung der IPv4-Adresse in 8 bit. Nach jedem 8. bit steht ein Punkt.
2. 8*4 Ziffern
3.  
4. Sie werden durch Doppelpunkte voneinander getrennt.
5. Zuerst muss man IPv6 enablen und dann wie gehabt gleich wie bei IPv4 vorgehen.
6. Es werden alle direkt an das Netzwerk angeschlossenen Geräte kontaktiert.
7. Sind von einem Router automatisch zugewiesene Adressen die zur Netzwerkinternen komunikation genützt ohne Globale Adressen zu verwenden.
8. Internetverbindung ohne DHCP.

ARP (Address Resolution Protocol

Aufgabenstellung: Sehen Sie sich das Video unter https://www.youtube.com/watch?v=hx9ZZivtzEE&spfreload=10 an. Führen Sie alle vorgeführten Schritte selbst auf Ihrem Rechner aus und dokumentieren Sie alle wesentlichen Schritte (wenn möglich mit Screenshots) auf Ihrem Blog.

IP addresses help us to reach/find networks 
To deliver actual frames on a local network, we need the MAC-addresses.

To solve this problem we have the ARP because it gets the MAC-address from the IP-address where we delivered it.

arp -?:

arp -a:

then we used the programm "Wireshark"..

it shows us the different Protocols and other things that happen in a network.

IPv6 Neighbor Discovery an Wireshark

Important terms in Wireshark:

• SMB2

Server Message Block, Lan-Mannager, NetBIOS-Protocol
It is an application-layer network protocol used for providing shared access to files, printers, serial ports, and miscellaneous communications between nodes on a network.

• Neighbor Discovery Protocol

Is used instead of the adress resolution protocol from IPv4.

- Router advertisment
- Neighbor advertisment
- Router solisitation message
-  

IPv6

First watch this video to know what i am talking about.

https://www.youtube.com/watch?v=mvlBMogudkQ 

Differences about IPv4 and IPv6:

IPv4:

192.168.201.113 is a tipical IPv4 address.

A IPv4 address has 32 bits and consists of dots and decimal numbers. There are only 4 billion address possible.

IPv6:

A524:72D3:2C80:DD02:0029:EC7A:002B:EA73 is a tipical IPv6 address.

A IPv6 address has 128 bits and consists of colons and hexadecimal numbers. There are 3,8*10^38 address possible.

Larger address space:
Global reachability and flexibility
Aggregation
Multihoming
Autoconfiguration
Plug-and-play
End-to-end without NAT
Renumbering

Mobility and security:
Mobile IP RFC-compliant
IPsec mandatory (or native) for IPv6

Simpler Header:
Routing efficiency
Performance and forwarding rate scalability
No broadcasts
No checksums
Extension headers
Flow Labels

Transition richness:
Dual stack
Translation

Questions we got from the teacher:

• How many possible addresses are at IPv6? How many times is this more compared to IPv4?

            There are 3,4 * 10^38 addresses possible .

             It's 8,5*10^28 more times compared to IPv4.

• Why are IPv6 addresses written in hexadecimal form?

             Because the hexadecimal has got 16bit, the range is from 0-9 and from A-F. So you                              have more possibilities.

• What is the possibility at IPv6, in difference to IPv4?

           The header of IPv6 gives you the opportunity to involve together chained extensions. So the                actually header is going to be shorter and the header of not used extensions isn't going on.

              Through those properties, the header of IPv6 can load faster.

• What is "Autoconfiguration" and "Renumbering"?

                Autoconfiguration: In IPv6 the hosts are able to configure their IPv6 address and their                         default router settings.

                Renumbering: In IPv6 networks can be renumbered. Routers can send a new prefix to tell                   the devices to regenerate their IP address.

• What is IPsec and which function has it at IPv6?

               Internet Protocol Security

               It protects the communication by authenticating and encrypting every IP-packet of a                            session.

• What is used instead of a broadcast-message?

              A multicast is used instead of a broadcast-message.

• How is the transition of IPv4 to IPv6 effected?

            The transition takes place through tunneling.

• What happens at the interface of a Cisco-Router, if a IPv6 address will be activated?