1. Regional Cisco Networking Academy Conference 2014
Introduction to IPv6:
Exactly the same as IPv4… only completely different
Rick Graziani
CS/CIS Instructor
Cabrillo College
Giving you the knowledge and confidence to teach IPv6

2. Topics A lot of stuff, but don’t be intimidated! Why IPv6?
IPv6 and ICMPv6 at a glance
Format of an IPv6 Address
IPv6 Address
Global Unicast IPv6 Address
Subnetting
Link-Local Unicast IPv6 Address
Static Configuration of a Global Unicast Address
Dynamic Configuration of a Global Unicast Address
Three options
Link-local address
Multicast address
Address Resolution
A lot of stuff, but don’t be intimidated!

3. Why are they making me learn IPv6?

4. We’re running out of IPv4
Monday, January 31, IANA allocated the last /8 IPv4 address blocks to the RIRs.
RIR’s have very few IPv4 address left, if any.
Many ISPs are severely limited and some have already run out.

5. Internet Penetration Rate by Population
About 80% of North America
has Internet access
Some ISPs are only giving out IPv6
Only 28% of Asia and 16%
of Africa has Internet access

6. Internet of Everything
Cisco defines the Internet of Everything (IoE) as bringing together people, process, data, and things to make networked connections more relevant and valuable than ever before.
Cisco estimates that there will be 50 billion “connected” devices by 2020.
That’s a lot of addresses!

7. No more NAT as we know it 192.168.1.0/24 RFC 1918 Private Address
Public IPv4 Address
Using NAT to “hide” IPv6 networks has been the source of some debate.
IETF continues to state that NAT is not a security feature.
NAT for IPv4 breaks many things.
IETF does not support the concept of translating a “private IPv6” address to a “public” IPv6 address... but there are exceptions.

8. Benefits of IPv6 Larger address space Stateless autoconfiguration
End-to-end reachability without private addresses and NAT
Better mobility support
Peer-to-peer networking easier to create and maintain, and services such as VoIP and Quality of Service (QoS) become more robust.
The “killer application” for the Internet is the Internet itself.

9. You are probably already running IPv6RS RA
IPv4
IPv6
IPv4
IPv6 R1
Rouge RA
Here is an IPv6 prefix and gateway
Here is an IPv6 prefix and gateway
I need an IPv6 prefix
IPv4
IPv6
Windows Vista or later, Mac OSX, Linux already running IPv6
Packet analyzer (Wireshark)
Potential man-in-the-middle attack
RS (Router Solicitations) and RA (Router Advertisements) described in other lessons.
Get familiar with IPv6!

10. I bought a /24 on eBay and I’m doing NAT444444, so I’m good!
Now’s the time
“Finding “creative” ways to keep IPv4 alive without transitioning to IPv6 is like rearranging deck chairs on the titanic.” IETF
IPv4 is not going away any time soon, but it will be replaced by IPv6
Now is the time to learn, test and become familiar with IPv6

11. IPv6 at home Learn IPv6 in the Lab
Implement IPv6 in a part of your network
See if you get IPv6 at home
Contact ISP
IPv6 enabled modem
IPv6 enabled router
Linksys ea6500 Router

12. When do I have to go to IPv6?
IPv4 and IPv6 will coexist for the foreseeable future.
Dual-stack – Device running both IPv4 and IPv6.
Enterprises and ISPs have to support both protocols, which is a reason to eventually go to only IPv6.

13. Various Transition Strategies – Mostly for ISPs
Tunneling – IPv6 packets encapsulated inside IPv4 packets.
NAT64 – Translating between IPv4 and IPv6.
Native IPv6 – All IPv6 (our focus and the goal of every organization).

14. IPv4 and IPv6 IPv6 is more than just larger address space.
It was a chance to make some improvements on the IP protocol.

15. IPv6 at a Glance Next Header = Protocol field in IPv4.
Indicates the data payload type (TCP, UDP, ICMPv6)
Hop Limit = TTL (Time to Live) in IPv4.
Number of router hops before packet is discarded.
Routers do not fragment IPv6 packets unless it is the source of the packet.
Use of a Link-Local Address.
ICMPv6 is more robust than ICMPv4.
SLAAC (Stateless Address Autoconfiguration) for dynamic addressing.

16. Internet Control Message Protocol (ICMPv6)
IPv6 Next Header Value: 58 decimal or 3A hexadecimal
ICMPv6 Header
ICMPv6 Message Body
Next Header 58
IPv6 Header
IPv6 Data
Described in RFC 4443
Much more robust than ICMP for IPv4
Contains new functionality and improvements.
More than just “messaging” but “how IPv6 conducts business”.
General message similar to ICMP for IPv4 (Type and Code fields)

17. Neighbor Discovery Protocol Uses ICMPv6
ICMPv6 informational messages used by Neighbor Discovery (RFC 4861):
Router Solicitation Message
Router Advertisement Message
Discussed with dynamic configuration of IPv6 addresses
We will also introduce assigned multicast addresses
Neighbor Solicitation Message
Neighbor Advertisement Message
Discussed with address resolution (IPv4 ARP)
We will also introduce solicited node multicast address
Redirect Message (Similar to ICMPv4)
Router-Device Messaging
Device-Device Messaging

18. Understanding the format of IPv6 Address

19. IPv6 Address Notation One Hex digit = 4 bits
2001:0DB8:AAAA:1111:0000:0000:0000:0100/64
2001 : 0DB8 : AAAA : 1111 : 0000 : 0000 : 0000 : 0100
16 bits 1
16 bits 2
16 bits 3
16 bits 4
16 bits 5
16 bits 6
16 bits 7
16 bits 8
IPv6 addresses are 128-bit addresses represented in:
Eight 16-bit segments or “hextets” (not a formal term)
Hexadecimal (non-case sensitive) between 0000 and FFFF
Separated by colons
Reading and subnetting IPv6 is easier than IPv4!

20. How many addresses does 128 bits give us?
2001:0DB8:AAAA:1111:0000:0000:0000:0100/64
2001 : 0DB8 : AAAA : 1111 : 0000 : 0000 : 0000 : 0100
16 bits
16 bits
16 bits
16 bits
16 bits
16 bits
16 bits
16 bits
How many addresses does 128 bits give us?
340 undecillion addesses or …
340 trillion trillion trillion addresses or …
“50 billion billion billion addresses for every person on earth” or….
“A string of soccer balls would wrap around our universe 200 billion times!” … in other words …
You won’t need to learn IPv7 for the next version of CCNA!

21. This isn’t the first time
Early versions of CCNA included:
IPv4
Appletalk
IPX

22. Rule 1: Leading 0’s
Two rules for reducing the size of written IPv6 addresses.
The first rule is: Leading zeroes in any 16-bit segment do not have to be written.
2001 : 0DB8 : 0001 : 1000 : 0000 : 0000 : 0ef0 : bc00
2001 : DB8 : 1 : 1000 : 0 : 0 : ef0 : bc00
2001 : 0DB8 : 010d : 000a : 00dd : c000 : e000 : 0001
2001 : DB8 : 10d : a : dd : c000 : e000 : 1
2001 : 0DB8 : 0000 : 0000 : 0000 : 0000 : 0000 : 0500
2001 : DB8 : 0 : 0 : 0 : 0 : 0 : 500
If any 16-bit segment has fewer than four hexadecimal digits, it is assumed that the missing digits are leading zeroes.

23. Rule 2: Double colon :: equals 0000…0000
The second rule can reduce this address even further:
Any single, contiguous string of one or more 16-bit segments consisting of all zeroes can be represented with a double colon.
FE80 : 0000 : 0000 : 0000 : 0000 : 0000 : 0000 : 0001
FE80 : : 1
FE80::1
Second Rule
First Rule

24. Rule 2: Double colon :: equals 0000…0000
Only a single contiguous string of all-zero segments can be represented with a double colon.
Both of these are correct…
FE80 : 0000 : 0000 : 0000 : 0014 : 0000 : 0000 : 0095
FE80 :: : 0 : 0 : 95 OR
FE80 : 0 : 0 : 0 : 14 ::

25. Rule 2: Double colon :: equals 0000…0000
Using the double colon more than once in an IPv6 address can create ambiguity because of the ambiguity in the number of 0’s.
FE80::14::95
FE80:0000:0000:0000:0014:0000:0000:0095
FE80:0000:0000::0014:0000: :0095
FE80:0000:0014:0000:0000:0000:0000:0095

26. Network Prefixes
IPv4, the prefix—the network portion of the address—can be identified by a dotted decimal netmask or bitcount.
or /24
IPv6 prefixes are always identified by bitcount (prefix length).
Prefix length notation:
2001:0DB8:100:a::/64
bits
The address is followed by a forward slash and a decimal number indicating how many of the first bits of the address are the prefix bits.

27. IPv6 Addresses

28. IPv6 Addressing Unicast Multicast Anycast Assigned Solicited Node
FF00::/8
FF02::1:FF00:0000/104
Unspecified
Unique Local
Embedded IPv4
Global Unicast
Link-Local
Loopback
2000::/3
3FFF::/3
FE80::/10
FEBF::/10
::1/128
::/128
FC00::/7
FDFF::/7
::/80

29. Global Unicast Address (GUA)
Global Routing Prefix
Subnet ID
Interface ID
Range: 2000::/ ::
to 3FFF::/ ::
001
IANA’s allocation of IPv6 address space in 1/8th sections
Global unicast addresses are similar to IPv4 addresses
Routable
Unique

30. Global Unicast Address (GUA)
Global Routing Prefix
Subnet ID
Interface ID
Range: 2000::/ ::
to 3FFF::/ ::
001
Global unicast addresses are equivalent to IPv4 public addresses
Except under very specific circumstances, all end users will have a global unicast address
Terminology:
Prefix equivalent to network address
Prefix length equivalent to subnet mask in IPv4
Interface ID equivalent to host portion

31. Typical Global Unicast Address and Why We Love IPv6!
IPv4 Unicast Address /?
Network portion
Subnet portion
Host portion
32 bits
IPv6 Global Unicast Address
/48
/64
16-bit Fixed Subnet ID
Global Routing Prefix
Interface ID
128 bits
64-bit Interface ID = 18 quintillion (18,446,744,073,709,551,616) devices/subnet
16-bit Subnet ID = 65,536 subnets

32. /64 Global Unicast Addresses and the 3-1-4 rule
/48
/64
16 bits
16 bits
16 bits
16 bits
16 bits
16 bits
16 bits
16 bits
Global Routing Prefix
Subnet ID
Interface ID 3 1 4
2001 : 0DB8 : AAAA : 1111 : 0000 : 0000 : 0000 : 0100
3 + 1 = 4 (/64) : 4
2001:0DB8:AAAA:1111:0000:0000:0000:0100/64
2001:0DB8:AAAA:1111::100/64

33. Subnetting IPv6 and Why Our Students Will Love IPv6
Just increment by 1 in Hexadecimal:
2001:0DB8:AAAA:0000::/64
2001:0DB8:AAAA:0001::/64
2001:0DB8:AAAA:0002::/64
2001:0DB8:AAAA:000A::/64
Valid abbreviation is to remove the 3 leading 0’s from the first shown quartet
2001:0DB8:AAAA:1::/64
3-1-4 Rule

34. Subnetting into the Interface ID
/48
/112
48 bits
64 bits
16bits
Global Routing Prefix
Subnet ID
Prefix
Interface ID
Global Routing Prefix
Subnet-ID
Interface ID
2001 : 0DB8 : AAAA : 0000 : 0000 : 0000 : 0000 : 0000
2001 : 0DB8 : AAAA : 0000 : 0000 : 0000 : 0001 : 0000
2001 : 0DB8 : AAAA : 0000 : 0000 : 0000 : 0002 : 0000
thru
2001 : 0DB8 : AAAA : FFFF : FFFF : FFFF : FFFE : 0000
2001 : 0DB8 : AAAA : FFFF : FFFF : FFFF : FFFF : 0000

35. Subnetting on a nibble boundary
/48
/68
60 bits
48 bits
20 bits
Global Routing Prefix
Subnet ID
Interface ID
/68 Prefix
Subnetting on a nibble (4 bit) boundary makes it easier to list the subnets:
/64, /68, /72, etc.
2001:0DB8:AAAA:0000:0000::/68
2001:0DB8:AAAA:0000:1000::/68
2001:0DB8:AAAA:0000:2000::/68 through
2001:0DB8:AAAA:FFFF:F000::/68
/68

36. Subnetting within a nibble
/48
/70
48 bits
22 bits
58 bits
Global Routing Prefix
Subnet ID
Interface ID
/70 Prefix
Four Bits: The two leftmost bits are part of the Subnet-ID, whereas the two rightmost bits belong to the Interface ID.
2001:0DB8:AAAA:0000:0000::/
2001:0DB8:AAAA:0000:0400::/
2001:0DB8:AAAA:0000:0800::/
2001:0DB8:AAAA:0000:0C00::/
bits

37. Do we need the IPv6 equivalent to a /30? /127?
/48
/127
48 bits
79 bits
1bit
Global Routing Prefix
Subnet ID
127-bit Prefix
1 bit Interface ID
Beyond the scope of CCNA but may be of interest….
RFC Using 127-Bit IPv6 Prefixes on Inter-Router Links
Ping-Pong Attack
Neighbor Cache Exhaustion Issue
There are mitigation techniques for both.
If you still want to use a /127, reserve a separate /64 for each /127.
2001:0DB8:AAAA:F000::/64
2001:0DB8:AAAA:F000::A/127
2001:0DB8:AAAA:F000::B/127
2001:0DB8:AAAA:F001::/64
2001:0DB8:AAAA:F001::A/127
2001:0DB8:AAAA:F001::B/127

38. Global Unicast IPv6 Address Static Configuration

39. Stateless Autoconfiguration
Configuring a Global Unicast Address
Global Unicast
Manual
Dynamic
IPv6 Unnumbered
Stateless Autoconfiguration
IPv6 Address
DHCPv6
Static
EUI-64

40. Exactly the same as an IPv4 address only different.
R1(config)#interface gigabitethernet 0/0
R1(config-if)#ipv6 address 2001:db8:acad:1::1/64
R1(config-if)#no shutdown
R1(config-if)#exit
No space
Exactly the same as an IPv4 address only different.
No space between IPv6 address and Prefix-length.
IOS commands for IPv6 are very similar to their IPv4 counterpart.
All 0’s and all 1’s are valid IPv6 host IPv6 addresses.

41. R1(config)#interface gigabitethernet 0/1
R1(config-if)#ipv6 address 2001:db8:acad:2::1/64
R1(config-if)#no shutdown
R1(config-if)#exit
R1(config)#interface serial 0/0/0
R1(config-if)#ipv6 address 2001:db8:acad:3::1/64
R1(config-if)#clock rate 56000

42. show running-config command on router R1
R1# show running-config
<output omitted for brevity>
interface GigabitEthernet0/0
no ip address
duplex auto
speed auto
ipv6 address 2001:DB8:ACAD:1::1/64 !

43. show ipv6 interface brief command on router R1
R1# show ipv6 interface brief
GigabitEthernet0/0 [up/up]
FE80::FE99:47FF:FE75:C3E0
2001:DB8:ACAD:1::1
Link-local unicast address
Global unicast address
Link-local address automatically created when (before) the global unicast address is.
We will discuss link-local addresses soon.

44. PC1: Static Global Unicast Address
2001:db8:acad:1::10 64
2001:db8:acad:1::1 (or link-local address)

45. PC1: Static Global Unicast Address
PC1> ipconfig Windows IP Configuration Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : IPv6 Address : 2001:db8:acad:1::10 Link-local IPv6 Address : fe80::50a5:8a35:a5bb:66e1 Default Gateway : 2001:db8:acad:1::1

46. Pinging a Global Unicast IPv6 Addresses
Ping uses ICMPv6 Echo Request and Echo Reply messages similar to ICMPv4.
PC1> ping 2001:db8:acad:1::1
Pinging 2001:db8:acad:1::1 from 2001:db8:acad:1::100 with 32 bytes of data:
Reply from 2001:db8:acad:1::1: time=1ms
Ping statistics for 2001:db8:acad:1::1:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 1ms, Maximum = 1ms, Average = 1ms
PC1>

47. Global Unicast IPv6 Address Dynamic Configuration

48. Dynamic Configuration of IPv6 Addresses
Global Unicast
Manual
Dynamic
IPv6 Unnumbered
Stateless Autoconfiguration
IPv6 Address
DHCPv6
Static
EUI-64

49. IPv4 Dynamic Addresses
DHCP Server

50. With IPv6 it begins with the Router Advertisement
To all IPv6 routers: I need IPv6 address information
ICMPv6 Router Solicitation
DHCPv6 Server
To all IPv6 devices:
Let me tell you how to do this …
ICMPv6 Router Advertisement
ICMPv6 Neighbor Discovery
Router Solicitation
Router Advertisement
The Router Advertisement (RA) tells hosts how it will receive IPv6 Address Information.
Sent periodically by an IPv6 router or…
… when the router receives a Router Solicitation message from a host.

51. ICMPv6 Router Advertisement
R1(config)# ipv6 unicast-routing
DHCPv6 Server
Router Advertisement/Solicitation Messages
Part of ICMPv6 (Internet Control Message Protocol for IPv6)
Router Advertisements (RA) are sent by an “IPv6 router” – ipv6 unicast-routing command
Forwards IPv6 Packets
Can be enabled for IPv6 static and dynamic routing
Sends ICMPv6 Router Advertisements
Note: Routers can be configured with IPv6 addresses without being an IPv6 router

52. SLAAC (Stateless Address Autoconfiguration)
Option 1 and 2: Stateless Address Autconfiguration – DHCPv6 Server does not maintain state of addresses
Option 3: Stateful Address Configuration – Address received from DHCPv6 Server
DHCPv6
R1(config)# ipv6 unicast-routing
DHCPv6 Server
Option 1: SLAAC (Default on Cisco routers)
“I’m everything you need (Prefix, Prefix-length, Default Gateway)”
Option 2: SLAAC + Stateless DHCPv6 for DNS address
“Here is my information but you need to get other information such as DNS addresses from a DHCPv6 server.”
Option 3: All addressing except default gateway – DHCPv6
“I can’t help you. Ask a DHCPv6 server for all your information.” RA

53. Router Advertisement – Option 1 SLAAC
2001:DB8:ACAD:1::/64
MAC: B-8C-E0-80 1
Option 1 – RA Message
To: FF02::1 (All IPv6 devices multicast – more later)
From: FE80::1 (Link-local address)
Prefix: 2001:DB8:ACAD:1::
Prefix-length: /64 2 RA
Prefix: 2001:DB8:ACAD:1::
Prefix-length: /64
Default Gateway: FE80::1
Global Unicast Address:
2001:DB8:ACAD:1: + Interface ID 3
EUI-64 Process or Random 64-bit value
DHCPv6 Server

54. Dynamic Interface ID Router Advertisement 2001:DB8:ACAD:1::/64
DHCPv6 Server
/48
/64
64 bits
Global Routing Prefix
Subnet ID
Interface ID
SLAAC
EUI-64 Process
Randomly Generated Number
(Privacy Extension)
Windows operating systems, Windows XP and Server 2003 use EUI-64.
Windows Vista and newer; hosts create a random 64-bit Interface ID.
Linux: Mostly use random 64-bit number
Mac OSX: use EUI-64 (on my Macs)

55. EUI-64 (Extended Unique Identifier – 64)
2001:DB8:ACAD:1::/64
MAC: B-E9-D4-80 1
Option 1 – RA Message
To: FF02::1 (All IPv6 devices multicast)
From: FE80::1 (Link-local address)
Prefix: 2001:DB8:ACAD:1::
Prefix-length: /64 2 RA
Prefix: 2001:DB8:ACAD:1::
Prefix-length: /64
Default Gateway: FE80::1
Global Unicast Address:
2001:DB8:ACAD:1: + Interface ID
EUI-64 Process or Random 64-bit value
DHCPv6 Server

56. EUI-64 F F F E 00 03 6B E9 D4 80 02 03 6B FF FE E9 D4 80 OUI 24 bits
Device Identifier
24 bits
Hexadecimal 00 03 6B E9 D4 80
Step 1: Split the MAC address
Binary
F F F E
Step 2: Insert FFFE
Binary
Step 3: Flip the U/L bit
Binary
Modified EUI-64 Interface ID in Hexadecimal Notation 02 03 6B FF FE E9 D4 80
Binary

57. PC1: Global Unicast Address
Router Advertisement
EUI-64
PC1> ipconfig Windows IP Configuration Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : IPv6 Address : 2001:db8:acad:1: b-ff-fe-e9-d4-80 Link-local IPv6 Address : fe80:: b-ff-fe-e9-d4-80 Default Gateway : fe80::1
A 64-bit Interface ID and the EUI-64 process accommodate the IEEE specification for a 64-bit MAC address.

58. Option 2:Stateless DHCPv6
I created my own address,
have a prefix-length, default gateway, but I need a DNS address…
ICMPv6
Router Advertisement
DHCPv6
DHCPv6 Server
Other Configuration Flag is set.
Use me for your address information just like SLAAC but…
… you need to get other information from a DHCPv6 server like possibly a DNS server address.
Learn how to configure the RA message and the Stateless DHCPv6 server in the Intermediate IPv6 presentation 

59. Option 3: Stateful DHCPv6
The router’s Router Advertisement tells me it can’t help me and I need to communicate with a stateful DHCPv6 server…
ICMPv6
Router Advertisement
DHCPv6
DHCPv6 Server
Managed Configuration Flag is set.
Get ALL of your address information from a DHCPv6 server except use my link-local address for your default gateway address.
Learn how to configure the RA message and the Stateful DHCPv6 server in the Intermediate IPv6 presentation 

60. What about Stateful DHCPv6?
DHCPv6 is similar to DHCPv4.
Host operating systems “may” include the option of ignoring the Router Advertisement from the router and only use the stateful services of a DHCPv6 server.
Note: All addresses should be checked before use with DAD (Duplicate Address Detection), similar to gratuitous ARP in IPv4.
DHCPv6
DHCPv6 Server

61. The World of IPv4 – DHCPv4 and NAT
G0/1
G0/1
HOME
G0/0
ISP
DHCPv4
Public IPv4 Address
for the interface
Private IPv4 Address
DHCPv4 /8
/12
/16
What about DHCP and IPv6 for my home network – First IPv4 at home….
ISP only has to deliver a public IPv4 address for Home router interface.
DHCP and RFC 1918 private address space is used for home network (ISP is not involved).
NAT is used for translation – but has its drawbacks!
No NAT (like that… kind of) for IPv6

62. The World of IPv6 – DHCPv6-PD (Prefix Delegation)
Complete IPv6 Reachability
Delegating Router (DR)
Requesting Router (RR)
G0/1
G0/1
G0/0
ISP-DR
HOME-RR
How does the home network get a “pubic” IPv6 address?
IPv6 Address for the interface:
SLAAC
DHCPv6 (Stateful or Stateless)
DHCPv6 with Prefix Delegation
In the Intermediate presentation we will learn the operations and configuration of DHCPv6-PD.

63. Link-Local Unicast IPv6 Addresses

64. IPv6 Addressing Unicast Multicast Anycast Assigned Solicited Node
FF00::/8
FF02::1:FF00:0000/104
Unspecified
Unique Local
Embedded IPv4
Global Unicast
Link-Local
Loopback
2000::/3
3FFF::/3
FE80::/10
FEBF::/10
::1/128
::/128
FC00::/7
FDFF::/7
::/80

65. Link-Local Communications
Link-local unicast
Link-Local Communications
Used to communicate with other devices on the link.
Are NOT routable off the link (network).
Only have to be unique on the link.
Are not included in the IPv6 routing table.
An IPv6 device must have at least a link-local address.
Used by:
Hosts to communicate to the IPv6 network before it has a global unicast address.
Router’s link-local address is used by hosts as the default gateway address.
Adjacent routers to exchange routing updates

66. Link-local Unicast Interface ID FE80::/10
10 bits
Remaining 54 bits
64 bits
/64
xx xxxx
Interface ID
FE80::/10
EUI-64, Random or Manual Configuration
Range: FE80::/ ::
to FEBF::/ ::

67. IOS uses EUI-64 to Create Link-Local Addresses
Wait! Two Link-Locals are the same!
G0/0
S0/0/0 R1
G0/1
R1#show interface gigabitethernet 0/0
GigabitEthernet0/0 is up, line protocol is up
Hardware is CN Gigabit Ethernet, address is fc c3e0 (bia fc c3e0)
<Output Omitted>
R1#show ipv6 interface brief
GigabitEthernet0/0 [up/up]
FE80::FE99:47FF:FE75:C3E0
2001:DB8:ACAD:1::1
GigabitEthernet0/1 [up/up]
FE80::FE99:47FF:FE75:C3E1
2001:DB8:ACAD:2::1
Serial0/0/ [up/up]
2001:DB8:ACAD:3::1
R1#
EUI-64
FF:FE = EUI-64 (most likely)
Serial interfaces will use a MAC address of an Ethernet interface.

68. PC1: Link-Local Unicast Address
PC1> ipconfig Windows IP Configuration Ethernet adapter Local Area Connection: Connection-specific DNS Suffix .: IPv6 Address : 2001:db8:acad:1:3496:1c51:3f57:fe89 Link-local IPv6 Address : fe80::3496:1c51:3f57:fe89 Default Gateway : fe80::1
Many operating systems will use a random 64-bit Interface IDs for GUA and Link- Local IPv6 Addresses.

69. Configuring Static Link-Local Addresses
G0/0 FE80::1
S0/0/0
FE80::1
G0/1
FE80::1 R1
Static addresses are more easily remembered and recognizable.
R1(config)#interface gigabitethernet 0/0
R1(config-if)#ipv6 address fe80::1 ?
link-local Use link-local address
R1(config-if)#ipv6 address fe80::1 link-local
R1(config-if)#exit
R1(config)#interface gigabitethernet 0/1
R1(config)#interface serial 0/0/0
R1(config-if)#
Link-Local Addresses only have to be unique on the link!

70. ipv6 enable command
Router(config)# interface gigabitethernet 0/1
Router(config-if)# ipv6 enable
Router(config-if)# end
Router# show ipv6 interface brief
GigabitEthernet0/ [up/up]
FE80::20C:30FF:FE10:92E1
Router#
Link-local unicast address only
Link-local addresses are automatically created whenever a global unicast address is configured
The ipv6 enable command will:
Create a link-local address when there is no global unicast address
Maintain the link-local address even when the global unicast address is removed

71. Pinging a Link-Local Address
FE80::1
FE80::2 R1
Ser 0/0/0 :1
Ser 0/0/0 :2 R2
FE80::1
2001:0DB8:ACAD:2::/64
2001:0DB8:ACAD:1::/64
G0/0
R1# ping fe80::2
Output Interface: ser 0/0/0
% Invalid interface. Use full interface name without spaces (e.g. Serial0/1)
Output Interface: serial0/0/0
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to FE80::2, timeout is 2 secs:
!!!!!
Must include exit-interface

72. Next-hop addresses in IPv6 Routing Tables
R1# show ipv6 route ospf
O :DB8:CAFE:2::/64 [110/657]
via FE80::2, Serial0/0/0
O :DB8:CAFE:3::/64 [110/1304]
O :DB8:CAFE:A002::/64 [110/1294]
R1#
Link-local addresses are used as next hop addresses

73. Multicast IPv6 Addresses

74. IPv6 Multicast IPv6 Addressing Unicast Multicast Anycast Assigned
Solicited Node
FF00::/8
FF02::1:FF00:0000/104
ICMPv6 Neighbor Discovery
Router Solicitation
Router Advertisement
ICMPv6 Neighbor Discovery
Neighbor Solicitation

75. IPv6 Multicast Similar to Multicast addresses for IPv4.
8 bits
4 bits
4 bits
112bits
Flag
Scope
Group ID
FF00::/8
Similar to Multicast addresses for IPv4.
Used to send a packet to a group of devices.
Two types:
Assigned
Solicited Node

76. Assigned Multicast Addresses
FE80::1
FF02::1
ICMPv6 Router Advertisement
FF02::1 – All IPv6 Devices
All IPv6 devices, including the router, belong to this group.
Every IPv6 device will listen and process packets to this address.

77. Assigned Multicast Addresses
FE80::0123:456:789A:BCDE
FF02::2
R1(config)# ipv6 unicast-routing
ICMPv6 Router Solicitation
FF02::2 – All IPv6 Routers
All IPv6 routers belong to this group.
Used to communicate with an IPv6 Router (ipv6 unicast routing)

78. Multicast Groups of a Router
R1# show ipv6 interface gigabitethernet 0/0
FastEthernet0/0 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::FE99:47FF:FE75:C3E0
Global unicast address(es):
2001:DB8:ACAD:1::1, subnet is 2001:DB8:ACAD:1::/64
Joined group address(es):
FF02::1
FF02::2
FF02::5
FF02::6
FF02::1:FF00:1
FF02::1:FF75:C3E0
<output omitted for brevity>
Member of these Multicast Groups
All-IPv6 devices on this link
All-IPv6 routers on this link: IPv6 routing enabled
OSPFv3 All OSPF Routers (similar to )
OSPFv3 All DR Routers (similar to )
Solicited-node multicast addresses
FF02 – “2” means link-local scope
What is a solicited node multicast address? Let’s talk address resolution.

79. Address Resolution

80. Address Resolution: IP to MAC Mapping
Know IPv4, what is the MAC?
My IPv4! Here is the MAC? 2 1
ARP Reply
ARP Request
PC1
PC2
ARP Cache 3 1
My IPv6! Here is the MAC? 2
Neighbor Advertisement
Neighbor Solicitation
Know IPv6, what is the MAC?
NeighborCache 3
IP to data link(MAC) address mapping:
IPv4 addresses use ARP
IPv6 addressing use ICMPv6 Neighbor Discovery messages
Neighbor Solicitation
Neighbor Advertisement
Devices store this mapping in their Neighbor Cache
ICMPv6 Neighbor Discovery
Neighbor Solicitation
Neighbor Advertisement

81. Address Resolution: IP to MAC Mapping
IPv4: ARP over Ethernet
Ethernet
ARP Request/Reply
ARP Request: Broadcast
Know IPv4, what is the MAC?
My IPv4! Here is the MAC? 2 1
ARP Reply
ARP Request
PC1
PC2 1
My IPv6! Here is the MAC? 2
Know IPv6, what is the MAC?
Neighbor Advertisement
Neighbor Solicitation
IPv6: ICMPv6 over IPv6 over Ethernet
Ethernet
IPv6 Header
ICMPv6: Neighbor Solicitation/Advertisement
NS: Multicast
NS: Solicited Node Multicast

82. Advantages of Multicast
Ethernet Broadcast
Destination MAC Address: Broadcast
Data must be passed to upper layer for processing.
IPv4 or IPv6 Multicast
IP multicast packets can be filtered by the switch, only sending packets to members of that group
IPv4 - IGMP (Internet Group Management Protocol)
IPv6 - MLD (Multicast Listener Discovery)
However, Solicited Node Multicasts are forwarded out all ports because of the potentially huge forwarding tables needed to to store these addresses. (For now.)
Ethernet Broadcast
Solicited Node multicast addresses
to be sent to every port to improve network robustment and
management.
IPv6 Addressing Architecture requires that all nodes must join the
associated Solicited-Node multicast addresses for every unicast and
anycast address it is assigned. This causes MLD snooping switches to
create potentially huge multicast forwarding tables just to handle
Neighbor Discovery. A simple change to alleviate this would be to
allow switches to forward a range of addresses that include the
Solicited-Node multicast addresses to every port. This also could
help in network discovery.
IPv4/IPv6 Multicast
IGMP/MLD Snooping

83. Why layer 2 multicast? ARP Requests: Layer 2 broadcasts:
Ethernet broadcasts are sent to all devices.
Flood the entire broadcast domain (subnet/VLAN).
Ethernet NIC must process the frame.
Any filtering is done by a higher layer protocol such as ARP.
Target IPv4
Address
Solicited Node Multicasts: Layer 2 and Layer 3 multicasts:
Although solicited node multicasts are forwarded out all ports, ….
Layer 2 multicast allows frames to be filtered by the NIC and not have send data to an upper layer protocol for inspection.

84. Neighbor Cache (IPv4 ARP Cache)
Neighbor Advertisement
Neighbor Cache
IPv6 Address MAC Address
2001:DB8:ACAD:1:: bd9.c644
PC1
IPv :DB8:ACAD:1::10
MAC bd9.c644
Neighbor Cache – Maps IPv6 addresses with Ethernet MAC addresses
Similar to ARP Cache for IPv4
5 States (2 noticeable and 3 transitory): (My CCNP Presentation)
Reachable: Packets have recently been received providing confirmation that this device is reachable.
Stale: A certain time period has elapsed since a packet has been received from this address.
Transitory States: INCOMPLETE, DELAY, PROBE

85. Neighbor Cache Windows: netsh interface ipv6 show neighbor
Linux/MAC: ip neighbor show
R1# show ipv6 neighbors
IPv6 Address Age Link-layer Addr State Interface
FE80::50A5:8A35:A5BB:66E bd9.c644 STALE Fa0/0
2001:DB8:ACAD:1:: bd9.c644 STALE Fa0/0
R1# ping 2001:db8:aaaa:1::100
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001:DB8:AAAA:1::100, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
2001:DB8:ACAD:1:: bd9.c644 REACH Fa0/0
R1#
Age
Time (in minutes) since the address was confirmed to be reachable. A hyphen (-) indicates a static entry.

86. ICMPv6 Review

87. Internet Control Message Protocol (ICMPv6)
IPv6 Next Header Value: 58 decimal or 3A hexadecimal
ICMPv6 Header
ICMPv6 Message Body
Next Header 58
IPv6 Header
IPv6 Data
Described in RFC 4443
Much more robust than ICMP for IPv4
Contains new functionality and improvements.
More than just “messaging” but “how IPv6 conducts business”.
General message similar to ICMP for IPv4
Also uses Type and Code fields like in ICMPv4.

88. Neighbor Discovery Protocol Uses ICMPv6
ICMPv6 informational messages used by Neighbor Discovery (RFC 4861):
Router Solicitation Message
Router Advertisement Message
Discussed with dynamic configuration of IPv6 addresses
Introduced with assigned multicast addresses
Neighbor Solicitation Message
Neighbor Advertisement Message
Discussed with address resolution (IPv4 ARP)
Introduced with solicited node multicast address
Redirect Message (Similar to ICMPv4)
Router-Device Messaging
Device-Device Messaging

89. Router Solicitations and Router Advertisements
Used by SLAAC (Stateless Address Autoconfiguration) 1
Router Solicitation Message
I need IPv6 address information.
FF02::2
All IPv6 Routers
PC1
DHCPv6 Server
Router Advertisement Message
Here is one of three options:
I have everything you need.
I have mostly what you need, but you will need to contact a DHCPv6 server for other information like a DNS address.
I have nothing for you. Contact a DHCPv6 serverl 2
FF02::1
All IPv6 Devices

90. Neighbor Solicitations and Neighbor Advertisements
Neighbor Solicitation Message
Whoever has the IPv6 Address 2001:DB8:ACAD:1::10 please send me your Ethernet MAC address. 1
PC2
Solicited Node Multicast
PC1 2
Neighbor Advertisement Message
I have the IPv6 Address 2001:DB8:ACAD:1::10. Here is my Ethernet MAC address:
0021:9bd9:c644.
Unicast
Address Resolution - A device knows the IPv6 address but needs the Layer 2 MAC address.
Unlike ARP, ICMPv6 Neighbor Solicitation/Advertisement messages are encapsulated in IPv6.
Information is stored in the Neighbor Cache.

91. Teach it and use it, and it will all make sense!
What we covered…
Why IPv6?
IPv6 and ICMPv6 at a glance
Format of an IPv6 Address
IPv6 Address
Global Unicast IPv6 Address
Subnetting
Link-Local Unicast IPv6 Address
Static Configuration of a Global Unicast Address
Dynamic Configuration of a Global Unicast Address
Three options
Link-local address
Multicast address
Address Resolution
Teach it and use it, and it will all make sense!

92. Quality time with my two nieces…
Web Site, Book, Etc.
Shameless plug!
Rick Graziani -
PowerPoints for CCNA, CCNP, IPv6
Username = cisco
Password = perlman
Quality time with my two nieces…

93. And…… Thank you very much!
Rick Graziani - Username = cisco Password = perlman