This presentation gives basic idea about IPv6 protocol.

1. Shreehari Dhat

2.  Background of IP addressing.
 IPv6 Terminology.
 What’s new in IPv6?
 IPv6 Packet Format.
 IPv6 Addressing architecture.
 IPv6 configuration on Windows/Linux.

3.  IP address is logical (implemented in software).
 IP address is used to identify a host over the network.
 IPv4 is most widely and commonly implemented.
 Range of IPv4 address.
IPv4 is 32 bit long address.
About 4,29,49,67,296 addresses are available.
 IANA (Internet Assigned Numbers Authority) manages the IP
address allocation globally.

4.  IPv4 address classes.
Class A address :- 0.0.0.0 – 127.255.255.255
Class B address :- 128.0.0.0 – 191.255.255.255
Class C address :- 192.0.0.0 – 223.255.255.255
Class D address :- 224.0.0.0 – 239.255.255.255 (Multicast)
Class E address :- 240.0.0.0 – 255.255.255.255 (Experimental)
 Class A, B & C are mainly used for allocating IP addresses
locally & globally.

5.  Global IP address and Local IP address
Global IP (Know Yip)
Global IP
ISP Backbone N/W
Global IP
Global IP
Organization 1
Organization 2
Organization 3
Internet
LAN

6.  Number of networks and hosts/network in A, B & C
Class A :- 256 Networks, 1,67,77,216 hosts/network.
Class B :- 65,536 Networks, 65,536 hosts/network.
Class C :- 1,67,77,216 Networks, 256 hosts/network.
 These numbers are derived from default NetMasks.
Class A :- 255.0.0.0
Class B :- 255.255.0.0
Class C :- 255.255.255.0

7.  Host:- Any computer which is not a router.
 Interface:- Connection to link.
 Link:- The medium for transmission.
 Link-Layer Identifier:- MAC address.
 Prefix:- Initial bits in IP address.
 Interface Address:- Addresses assigned to NIC.
 Multicast:- One to Many.
 Neighbors:- computers attached to same link.

8.  Larger address space i.e.
128 bits address.
Address count:-340,282,366,920,938,463,463,374,607,431,768,211,456 (3.4 × 10^38)
 Almost all blocks of IPv4 address have been assigned globally.
 The last unassigned top-level address blocks of 16 million IPv4
addresses were allocated in February 2011.
 Was there an IPv5 before IPv6?
Ans:- Yes. It was experimental protocol. Basically designed for
streaming purpose (QoS).

9. IPv4 IPv6
Address space:- 4.4 billion addresses only. Address space:- trillions of addresses.
IP Security (IPSec) is optional.
Fragmentation at sender & routers.
In-built IPSec support.
Fragmentation only at sender level.
Option fields are part of header.
Header length + Protocol length.
New Extension header added to IP
header.
Only Payload length.
Broadcast messages.
Address Resolution Protocol.
No broadcast in IPv6.
Neighbor discovery protocol.
Address allocation is based on class.
No router advertisement.
No Stateless address allocation.
Address allocation is based on network
prefix. Router advertisement.
Stateless address allocation (Link Local).

10. Version Traffic Class Flow Label
Payload Length Next Header Hop Limit
Source Address
Destination Address

11.  Version :- 4-bit Internet Protocol version number = 6.
 Traffic Class :- 8-bit traffic class field.
 Flow Label :- 20-bit flow label. Determine the packet sequence.
 Payload Length :- 16-bit unsigned integer. Length of the
IPv6 payload, i.e., the rest of the packet following this IPv6 header, in octets.
Next Header :- 8-bit selector. Identifies the type of header immediately following the IPv6 header
 Hop Limit :- 8-bit unsigned integer. Decremented by 1 by each node that forwards the pac-
ket. The packet is discarded if Hop Limit is decremented to zero.
 Source & Destination Address :- 128-bit address.

13. Extension Headers:-
Order of Processing headers
IPv6 header
Hop-by-Hop Options header (0)
Destination Options header-(First)
Routing header (43)
Fragment header (44)
Authentication header (51)
Encapsulating Security Payload header (50)
Destination Options header-(Last) (60)
upper-layer header(6-TCP, 17-UDP, 58-ICMP)

14.  Each Extension header has two fields mandatory:-
 Some of the headers are not examined or processed by router.
So improved performance for transmission of data.
 Only Hop-by-Hop EH is compulsory.
Header specific data
Next Header Hdr Ext Len

16.  IPv6 is implemented with 128 bit addressing mechanism.
 Three basic types of addresses
1. Unicast – Single receiver interface address.
2. Multicast – A group of receivers.
3. Anycast – One of nearest interface addresses.
 IPv6 addresses are assigned to interface, not hosts/nodes.
 Single interface can have multiple IPv6 addresses.
 No broadcast addresses in IPv6.

17.  Representation of IPv6 address.
16 Bits
FEDC:BA98:7654:3210:FEDC:BA98:7654:3210
1111 1110 1101 1100:10111010 1001 1000:0111 0110 0101 0100:0011 0010 0001 0000: 1111 1110 1101 1100:10111010 1001 1000:0111 0110 0101 0100:0011 0010 0001 0000
 Examples
FEDC:BA98:7654:0000:0000:0000:0000:3210
Or FEDC:BA98:7654:0:0:0:0:3210

18. Successive 0s can be replaced with :: but only once.
FEDC:BA98:7654:0000:0000:0000:0000:3210
FEDC:BA98:7654::3210
But this is wrong:-
FEDC:0000:0000:0000:FEDC:0000:0000:3210
FEDC::FEDC::3210

19.  Unspecified address
0:0:0:0:0:0:0:0 or ::
 Loopback address
0:0:0:0:0:0:0:1 or ::1
 IPv4 mapped IPv6 address
::ffff:c000:0280 ::ffff:192.0.2.128
 URL with IPv6 address
http://[2001:1:4F3A::206:AE14]:8080/index.html

20.  Global Unicast Address:-
3 Bits 13 Bits 8 Bits 24 Bits 16 Bits
001 - Identifies the address as an IPv6 Unicast global address.
TLA ID - Identifies the highest level in the routing hierarchy. TLA IDs are administered by
IANA.
RES – Reserved for future use.
NLA ID - Identifies a specific customer site.
SLA ID - Enables as many as 65,536 (216) subnets within an individual organization’s site.
The SLA ID is assigned within the site; an ISP cannot change this part of the address.
Interface ID - Identifies the interface of a node on a specific subnet.
001 TLA ID SLA IDRES NLA ID Interface ID (64 bits)

21.  Link Local address:- Automatically generated by OS using
MAC address.
FE80::250:56FF:Fe8F:775F/10. A & B can communicate
directly, but not with C, D & vice versa.
A B C D
LAN Switch

22.  Generation of Link-local IPv6 address.
MAC address - 00:50:56:8F:52:AA
Insert FFEE in the middle of MAC address and make a group
of 2 bytes.
0050:56FF:FE8F:52AA
0000 0000 0101 0000 : 0101 0110 1111 1111 : 1111 1110 1000 1111 : 0101 0010 1010 1010
Flip the 2nd bit of highest byte and append FE80 like
FE80::250:56FF:FE8F:52AA

23.  Unicast Site local address.
10 Bits 32 Bits 16 Bits 64 Bits
Starts with FEC0: prefix
Similar to IPv4 Private address.
Provides 65,536 subnets.
1111 1110 11 All 0’s Subnet ID Interface ID

24.  Multicast IPv6 address
8 Bits 4 Bits 4 Bits 112 Bits
Starts with FF prefix.
The 4 bit flag indicates whether it’s a well-known multicast or
dynamic multicast address.
The 4 bit SC indicates whether it’s a link local, site local or
global multicast.
Group ID is unique within a scope.
1111 1111 Flag Group IDSC

25.  Configure IPv6 in Linux.
Refer link :- http://www.tldp.org/HOWTO/Linux+IPv6-
HOWTO/chapter-configuration-address.html
 Configure IPv6 in Solaris.
Refer link :- http://docs.oracle.com/cd/E19253-01/816-
4554/ipv6-config-tasks-64/index.html
 Configure IPv6 in Windows:- It is same as configuring IPv4
from Control Panel.