Internet Protocol Version 5 was used by the Internet Stream Protocol, an experimental streaming protocol

The second version (of Internet Stream Protocol), known variously as ST-II or ST2, distinguishes its own packets with an Internet Protocol version number 5, although it was never known as IPv5. The Internet Stream Protocol family was never introduced for public use, but many of the concepts available in ST are similar to later Asynchronous Transfer Mode protocols and can be found in Multiprotocol Label Switching (MPLS). They also presaged Voice over IP.

IPv6 benefits:

• increased address space: 5 x 1028 addresses for each person on the planet
• simplified header

• No broadcasts
• Security and mobility features built-in
• No fragmentation: MTU discovery is performed for each session
• Can coexist with IPv4 during a migration

IPv6 Address structure:

• hexadecimal number - in the range 0 - F
• 32 hexadecimal digits x 4 bits per digit = 128 bits
• 16 bits x 8 fields = 128 bits total

IPv6 Abbreviation Rules:

• Leading zeros in a field can be omitted
• Contiguous fields containing all zeros ca be represented with a double colon (NOTE: This can only be done once for a single IPv6 address)

Global Unicast:

• Global - routed on the Internet
• Unicast - one-to-one communication
• Addressing starts with 2000::/3 ; assigned by the IANA

Attach:globalunicast.png

• 001 - start of Global Unicast addresses
• Global Routing Prefix - for routing on the public Internet
• Subnet ID - to carve up our network in different subnets
• Interface ID - to assign to specific interfaces

Multicast Address:

• Addressing has an FF as the first two hexadecimal digits

Attach:multicastaddress.png

• 1111 1111 - start of Multicast Address
• Flags - 4 bits

• Scope - 4 bits

Attach:multicastaddrscope.png

• Group ID - 112 bits - the group to which members are going to join

Link Local Address:

• addressing starts with FE80::/10
• can only communicate on one network segment = similar to the IPv4 APIPA address (169.254.0.0/16)
• can be automatically or statically assigned

Link Local Address:

• addressing starts with FE80::/10
• can only communicate on one network segment = similar to the IPv4 APIPA address (169.254.0.0/16)
• can be automatically or statically assigned

Attach:linklocaladdr.png

Why do we need it?

	- automatic address configuration on NIC
	- discovering neighbors
	- every NIC gets automatically a link local address 

Unique local address:

• addressing starts with FC00::/7 or FD00::/7
• cannot be routed over the public Internet
• similar to IPv4 private address
• If the address is locally assigned, the L bit is set to 1

Attach:uniquelocaladdr.png

Loopback address:

• written as ::1
• localhost
• similar to the IPv4 127.0.0.1 addresses
• can be used to verify the IPv6 stack is operating on a device

Attach:loopbackaddr.png

Unspecified address:

• written as :: - an address which has only zeroes
• DAD (Duplicate Address Detection) - used for a client's source address when sending a Neighbor Solicitation message
• used for a client's source address when sending a outer Solicitation message

Attach:unspecifiedaddr.png

Solicited-Node Multicast Address:

• address begins with FF02::1:FF
• address ends with the last 24 bits of the corresponding IPv6 address

Attach:solicitednodeaddr.png

Why to do that?

• used instead of an IPv4 ARP broad cast
• used for DAD (Duplicate Address Detection)

Modified EUI-64:

• 64-Bit Extended Unique Identifier (EUI-64) - taking the MAC address on the router interface and using it as the basis for creating the 64-bit interface ID
• The challenge: A MAC address is only 48 bits long
• ex.:

Attach:eui64.png

Important

	step 1: Split the MAC in the middle
		0015.2B         E4.9b60
	step 2: Insert FF.FE in the middle
		0015.2BFF.FEE4.9b60

	step 3: Change format to use a colon delimiter
		0015:2BFF:FEE4:9b60

	step 4: Convert the first eight bits to a binary
		0015:2BFF:FEE4:9b60
		|
	  00000000

	step 5: Flip the 7th bit
		U/L bit - 7th bit of a MAC address, which is set to a 0 for a universally unique MAC address and a 1 for a locally unique MAC address
		0015:2BFF:FEE4:9b60
		|
	  00000010

	Step 6: Convert the first eight bits back into hexadecimal
		0215:2BFF:FEE4:9b60

	From there on use of the EUI-64 is in the Link Local Address:
		=> FE80::215:2BFF:FEE4:9B60

Auto configuration:

• Stateful autoconfiguraiton Clients get their IPv6 addressing and parameters from a DHCPv6 server

Attach:statefulauto.png

• Stateless autoconfiguraiton: Clients get their IPv6 addressing and parameters from an IPv6 router

Attach:statelessauto.png

IPv6 traffic flows:

• unicast
• multicast
• no broadcast
• anycast