1. By : Santosh Yadav IIT Kanpur
IPv6 DHCP
By : Santosh Yadav
IIT Kanpur

2. IPv6 Dynamic Host Configuration Protocol Overview
Evolution Of DHCPv6
DHCPv6 Concepts
Installation
Configuration

3. Evolution Of DHCPv6
To boot the machines in a LAN, needs lot of network parameters to be configured in each machine.
In order to avoid this manual process, all the network parameters are put in a server and when a machine in LAN is booting, it will contact the server for the configuration parameters. This is called BOOTP server. Later it is extended to DHCP with additional features.
Generally called DHCP

4. Evolution Of DHCPv6
IP configuration in IPV6 is carried out by IPV6 auto-configuration
IPv6 auto-configuration
Stateless
nodes configure addresses themselves with
information from routers (if available);
no managed addresses
Stateful
nodes use DHCPv6 to obtain addresses.
Duplicate address detection (DAD) used to avoid
duplicated addresses

5. What is DHCPv6 ? The Dynamic Host Configuration Protocol for IPv6
Dhcpv6 Concepts
What is DHCPv6 ?
The Dynamic Host Configuration Protocol for IPv6
(DHCP) enables DHCP servers to pass configuration
parameters such as IPv6 network addresses to IPv6
nodes.
DHCPv6 protocol Released in RFC 3315
This protocol is a stateful counterpart to "IPv6 Stateless
Address Autoconfiguration" (RFC 2462).
Used separately or concurrently with the latter to obtain
configuration parameters.

6. The following lists the main differences between DHCPv4 and DHCPv6:
Dhcpv6 Concepts…
DHCPv6 Versus DHCPv4
The following lists the main differences between DHCPv4 and DHCPv6:
Unlike DHCPv4, IPv6 address allocation in DHCPv6 is
handled using a message option.
The message types, such as DHCPDISCOVER and
DHCPOFFER supported by DHCPv4 are removed in
DHCPv6. Instead, DHCPv6 servers are located by a client
SOLICIT message followed by a server ADVERTISE message
Unlike DHCPv4 clients, DHCPv6 clients can request multiple
IPv6 addresses.

7. A method of providing stateful IPv6 address configuration/assignment
Dhcpv6 Concepts…
Why we need dhcpv6 ?
A method of providing stateful IPv6 address configuration/assignment
Also provides “other” network information
DNS servers
NIS information
DHCP allows centralized control and
auditing of IP address assignments
Central point of control for resources
Dynamic DNS updates
More security versus stateless

8. Msg-type Transaction-id Options (variable)
Dhcpv6 Concepts…
DHCPv6 Basic Message Format
Msg-type
Transaction-id
Options (variable)
• SOLICIT
• ADVERTISE
• REQUEST
• CONFIRM
• RENEW
• REBIND
• REPLY
• RELEASE
• DECLINE
• RECONFIGURE
• INFORMATION-REQUEST
• RELAY-FORW
• RELAY-REPL

9. Message Type Option Meaning REBIND (6)
SOLICIT(1)
A client sends a Solicit message to locate servers.
ADVERTISE (2)
A server sends an Advertise message to indicate that it is available for DHCP service, in response to a Solicit message received from a client.
REQUEST (3)
A client sends a Request message to request configuration parameters, including IP addresses, from a specific server.
REPLY (4)
A server sends a Reply message containing assigned addresses and configuration parameters in response to a Solicit, Request, Renew, Rebind message received from a Client.
RENEW (5)
A client sends a Renew message to the server that originally provided the client's addresses and configuration parameters to extend the lifetimes on the addresses assigned to the client.
REBIND (6)
A client sends a Rebind message to any available server to extend the lifetimes on the addresses assigned to the client.

10. Messages exchanged using UDP
Dhcpv6 Concepts…
DHCP Messages
Messages exchanged using UDP
Client port – udp/546
Server Port – udp/547
Client uses Link-Local address or addresses determined using other methods to transmit and receive DHCP messages.
Server receives messages from clients using a reserved, Link-Scoped multicast address.

11. All_DHCP_Relay_Agents_and_Servers
Dhcpv6 Concepts…
DHCP Multicast Addresses
All_DHCP_Relay_Agents_and_Servers
Link-scoped multicast address used by a client to communicate with on-link relay agents and servers
FF02::1:2
All_DHCP_Servers
Site-scoped multicast address used by a relay agent to communicate with servers
FF05::1:3

12. Options data(option –len octets)
Dhcpv6 Concepts…
DHCPv6 option format and base option
Option-code
Option length
Options data(option –len octets)
• Client Identifier
• Server Identifier
• Identity Association for Non-temporary
Addresses
• Identity Association for Temporary
• IA Address
• Option Request
• Preference
• Elapsed Time
• Relay Message
• Authentication
• Server Unicast
• Status Code
• Rapid Commit
• User Class
• Vendor Class
• Vendor-specific Information
• Interface-Id
• Reconfigure Message
• Reconfigure Accept

13. Dhcpv6 Concepts…
DHCP Unique Identifer (DUID)
Each DHCP client and server has a DUID. DHCP servers use DUIDs to identify clients for the selection of configuration parameters and in client Identity Associations.
Unique across all clients and servers
Should not change over time (if possible)
Must be < 128 octets long

14. Client must associate at least one distinct IA with each
Dhcpv6 Concepts…
Identity Association
An identity association (IA) is a construct through which a server and client can identify, group, and manage a set of related IP addresses.
Client must associate at least one distinct IA with each
network interface requesting assignment of IP
addresses from DHCP server (IAID)
Must be associated with exactly one interface
Must be consistent across restarts by the client

15. DHCPv6 working DHCP client DHCP server B DHCP server A T I M E SOLICIT
ADVERTISE
ADVERTISE
REQUEST
Client select one advertise server B
REPLY
Client Now use address and parameter for lifetime
Client renew life time
RENEW
REPLY
Client releases address when shutting down
RELEASE

16. Dhcpv6 Concepts…
Dhcpv6 operation :
Client sends messages to link-local multicast address
Server unicasts response to client
Information-Request / Reply - provide client configuration
information but no addresses
Confirm / Reply - assist in determining whether client moved
Reconfigure - allow servers to initiate a client reconfiguration
Basic client/server authentication capabilities in base
standard.
DHCP Unique Identifier (DUID) used to identify clients &
servers
Identity Association ID (IAID) used to identify a collection of
addresses
Relay Agents used when server not on-link
Relay Agents may be chained

17. Ongoing Project
Previously DHCPv6 v1.001and now DHCPv available for the HP-UX 11i v1 and HP-UX 11i v2 operating systems
Dibbler is a portable DHCPv6 implementation on Linux 2.4/2.6 and Windows XP and Windows 2003.
This project was started as master thesis by Tomasz Mrugalski and Marek Senderski of Computer Science faculty on Gdansk University of Technology.
Project UNIX name: dhcpv6
Operating System: All POSIX (Linux/BSD/UNIX-like OSes), Linux

18. Update with dhcpv6-0.10-11_FC3.i386.rpm using
Installation
Dhcpv6 server :
Update with dhcpv _FC3.i386.rpm using
# rpm -U dhcpv _FC3.i386.rpm
Create a database directory
#mkdir /var/db/dhcpv6
Copy sample server configuration file
# cp dhcp6s.conf /etc/dhcp6s.conf
Start the server daemon using
# dhcp6s –dDf eth0

19. Update with dhcpv6_client-0.10-11_FC3.i386.rpm using
Installation…
Dhcpv6 client :
Update with dhcpv6_client _FC3.i386.rpm using
# rpm -U dhcpv6_client _FC3.i386.rpm
Copy sample client configuration file
# cp dhcp6c.conf /etc/dhcp6c.conf
Start the client daemon using
# dhcp6c –dDf eth0

20. In Fedora core 3 following files are configured :
Configuration
In Fedora core 3 following files are configured :
Server configuration :
/etc/sysconfig/dhcp6s
/etc/dhcp6s.conf
File : /etc/sysconfig/dhcp6s
Specify the interface for dhcp6s
DHCP6SIF=eth0

21. Server configuration... File : /etc/dhcp6s.conf Configuration…
interface eth0 {
server-preference 255;
renew-time 60;
rebind-time 90;
prefer-life-time 130;
valid-life-time 200;
allow rapid-commit;
link BBB {
pool{
range 2001:0E30:1402:2::4 to 2001:0E30:1402:2::ffff/64;
prefix 2001:0E30:1402::/48; };

22. In Fedora core 3 following files are configured :
Configuration…
In Fedora core 3 following files are configured :
Client configuration :
/etc/sysconfig/network-scripts/ifcfg-eth0
/etc/dhcp6c.conf
File : /etc/sysconfig/network-scripts/ifcfg-eth0
IPV6INIT=yes
DHCP6C=yes

23. client configuration... Configuration… interface eth0 {
File : /etc/dhcp6c.conf
interface eth0 {
#information-only;
send rapid-commit;
#request prefix-delegation;
#request temp-address;
address {
2001:0E30:1402:1:9656:3:4:56/64; };

24. Testing Start the server daemon in debug mode in foreground
#dhcp6s –dDf eth0
Restart the network service of client
#service network restart
See the address assignment
#ifconfig

25. Thank you for your attention
Any Question?

26. By : Kaveri Bhaumik IIT Kanpur
IPv6 Multicasting
By : Kaveri Bhaumik
IIT Kanpur

27. Topics covered are Definition of multicasting Multicast addresses
Comparison between IPv4 multicasting & IPv6 multicasting
VideoLAN Client (VLC) media player
Advantage of using multicasting in VLC
Installing VLC
UDP Streaming With VLC using the GUI

28. Definition of Multicasting
Multicast is communication between a single sender and multiple receivers on a network.
Together with anycast and unicast, multicast is one of the packet types in the Internet Protocol Version 6 (IPv6).

29. Graphical Representation Of Multicasting
Sending
Entity
Receiving
Entity
Service Provider
Receiving
Entity

31. IPv6 ADDRESSING
There are three types of addresses:
Unicast: An identifier for a single interface.
Anycast: An identifier for a set of interfaces and is delivered to one of the interfaces identified by that address.
Multicast: An identifier for a set of interfaces and is delivered to all interfaces identified by that address.
Note :-> There are no broadcast addresses in IPv6, their function being superseded by multicast addresses.

32. Multicast addresses
Multicast addresses always start with (xx is the scope value)
ffxy:
Multicast addresses format:
| | 4 | | bits |
| |flgs|scop| group ID |
Multicast addresses are split into scopes and types

33. Multicast addresses format…
at the start of the address identifies the address as being a multicast address.
flgs is a set of 4 flags: | 0 | 0 | 0 | T |
The high-order 3 flags are reserved.
T = 0 indicates a permanently-assigned ("well-known") multicast address, assigned by the global internet numbering authority.
T = 1 indicates a non-permanently-assigned ("transient") multicast address.

34. Multicast scopes ffx1: node-local ffx2: link-local ffx5: site-local
ffx8: organization-local
ffxe: global scope
others are reserved

35. Multicast types All Nodes Address:
ID = 1h, addresses all hosts on the local node (ff01:0:0:0:0:0:0:1) or the connected link (ff02:0:0:0:0:0:0:1).
All Routers Address:
ID = 2h, addresses all routers on the local node (ff01:0:0:0:0:0:0:2), on the connected link (ff02:0:0:0:0:0:0:2), or on the local site (ff05:0:0:0:0:0:0:2).

36. Comparison between IPv4 multicasting & IPv6 multicasting
Although the basic notion of multicasting is common to IPv4 and IPv6, several new characteristics are introduced in IPv6 multicasting.
In IPv4,multicasting was extension of the basic specification, while specifications of IPv6 require that all IPv6 nodes support multicasting.
IPv6 explicitly limits the scope of a multicast address by using a fixed address field, whereas the scope was specified using TTL (Time to Live) of a multicast packet in IPv4.

37. Comparison…
In IPv4, multicast tunnels were introduced to deploy multicasting .In IPv6,all routers should be multicast-capable, which means that we do not have to use multicast tunnels to deploy IPv6 multicasting.
IPv4 multicasting use unicast addresses to identify a network interface. However, this is not suitable for IPv6,as an IPv6-capable node may assign multiple addresses on a single interface, which tends to cause a configuration mismatch. In IPv6 ,to identify the interface the user must use specified interface index.

38. Implementation of multicasting
We have practically tested multicasting over IPv6 in IITK .
Muticasting in IPv6 has also been tested across the router using the global scope address .
For multicast testing we have used VideoLan Client media player which is a freeware.

39. VideoLAN Client (VLC) media player
VLC - the cross-platform media player and streaming server.
VLC is a multimedia player for various audio and video formats (MPEG-1, MPEG-2, MPEG-4, DivX, mp3, ogg, ...) as well as DVDs, VCDs, and various streaming protocols.
It can also be used as a server to stream in unicast or multicast in IPv4 or IPv6 on a high-bandwidth network.

41. Advantage of using multicasting in VLC
Problems encountered using unicast or broadcast are :
with unicast, when a lot of clients want to receive the stream, the network interface of the server becomes saturated.So the number of clients is very limited, especially when the stream is big.
with broadcast, the machines that do not want to receive the stream are polluted and some devices do not like to receive huge broadcasts. If you want to send several streams at the same time, the network becomes oversaturated.

42. Advantage of using multicasting in VLC…
With multicast, the packets are sent on the network to a multicast IP group which is designated by its IP address.
The machines can join or leave a multicast group by sending a request to the network. The request is usually sent by the kernel of the operating system.
The VLC takes care of asking the kernel of the operating system to send the join request.
It is possible for one client to belong to several groups.

43. Showing a scenario giving example of multicasting
Server(vlc) Network Clients(vlc)
stream > ff1e:: > client n°1
| > client n°2
< client n°3 join
join ff1e::1
Server(vlc) Network Clients(vlc)
| > client n°1
stream > ff1e:: > client n°2
| > client n°3

44. Scenario of multicasting…
Server(vlc) Network Clients(vlc)
< client n°1 leave
leave ff1e::1
stream > ff1e:: > client n°2
| > client n°3

45. Above packages are available in http://www.videolan.org/
Installing VLC
For Fedora Core 3 :
Download the VLC Binaries packages
vlc-binary.tar.gz
For Windows :
Download the self-extracting package
vlc win32.exe
Above packages are available in

46. To run the VLC Type the following command to run VLC: $vlc
This is the VLC media player:

47. UDP Streaming With VLC using the GUI
Server – Send the Data
Select File – Open File, and Browse to select a file.
Select the “Stream output” checkbox, then the Settings button – this opens a Stream Output window.
Output Methods
For multicasting, select UDP and write following :
address : ff1e and port : 1234
Select the checkbox : Play locally

48. UDP Streaming… Stream Output window

49. UDP Streaming… Client – Receive the Data Open VLC on the receiving PC.
Select File – Open Network Stream.
To join the session of multicast as sent by
the server do the following :
Select UDP/RTP multicast and write :
address : ff1e and port : 1234
Click the OK button, and the VLC display window should open.

50. THANK YOU FOR YOUR ATTENTION
Reference
Further information about VLC can be obtained from :
THANK YOU FOR YOUR ATTENTION
Any Questions?