1. Internet ProtoCOL Version 6 I/II
PS2 2015
Martin Pokorný

2. Reasons for a new IP protocol
IPv4/IPv6 – Addressing & Packet forwarding
Why a new IP protocol?
IPv4 – IPv4 address space exhaustion
IPv6 – IPv6 address … 128 bits => 2128 = 3,4 × 1038
– Address space aggregation … IANA site
– Simplified header, no broadcasts, …

3. IPv6 Address Notation General form
hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh
8 × hhhh … Blocks, Segments, Quartets => 16 bits
32 × h … Hexadecimal digit (0-9, a-f)
Example
2001:0000:a000:0001:0000:0000:0000:0000
Two rules to make the address shorter:
Leading zeros in a quartet can be omitted, one number must remain. 2001:0000:a000:0001:0000:0000:0000:0000 → 2001:0:a000:1:0:0:0:0
One or more consecutive quartets with a null value can be replaced with a double-colon (::), once in the whole address only :0:a000:1:0:0:0:0 → 2001:0:a000:1::

4. Network Prefix and Interface-ID
IPv6-Address | Network Prefix | Interface ID | ← Prefix Length → No „subnet mask“ … Prefix length, Notation /x Network address … Interface ID = 0 Example Host-Address 2001:718:803:1:a00:27ff:fefc:152 Network-Address 2001:718:803:1::/64

5. Address Assignment – Global Unicast
Global Unicast Addresses: prefix 2000::/3 reserved
Global Unicast Address Assignment Strategy
IANA (/3) -> RIR (/23) -> LIR (/32) -> Customer (/48)
Global Routing Prefix (Site Prefix): /48
MENDELU Example
IANA Global Unicast … 2000::/3
RIPE NCC RIR … 2001:600::/23
CESNET LIR … 2001:718::/32
MENDELU … 2001:718:803::/48
RIPE Database
IANA IPv6 Global Unicast Address Assignments

6. Subnet Addressing
/0 /48 /64 /128 | Global Routing Prefix | Subnet | Interface ID |
1.–3. Quartet
4. Quartet
5.–8. Quartet

7. Interface ID
/0 /48 /64 /128 | Global Routing Prefix | Subnet | Interface ID |
1.–3. Quartet
4. Quartet
5.–8. Quartet
Static Manual configuration, e.g. 2001:718:803:1::1
EUI-64 Extended Unique Identifier 64-bit
Random Privacy Extensions – due to security reasons

8. EUI-64
EUI-64
The 64-bit Interface Identifier generated from the 48-bit MAC Address.
MAC Address divided into two halves 00:01:02:aa:bb:cc
The 7. bit in the 1. byte (U/L-Bit) inverted 02:01:02:aa:bb:cc
FFFE inserted :02FF:FEaa:bbcc

9. IPv6 Address Types 1/4
Special Addresses ::/128 Unspecified ::1/128 Loopback
Listen on all network interfaces
Local communication

10. IPv6 Address Types 2/4
Global Unicast Addresses 2000::/3 (not only this one…) „Global“ => world-unique address „Unicast“ => identifies one network interface card Routable =>

11. IPv6 Address Types 3/4
Link Local Unicast Addresses FE80::/10 | FE80 (10 bits) | 54 × 0 | Interface ID |
Local communication, no forwarding

12. IPv6 Address Types 4/4
Multicast Adresses FF00::/8 … a group of hosts Address scope (e.g.) FF02 … Link-Local FF05 … Site-Local
FF02::2 … All IPv6 Routers
FF02::1 … All IPv6 Hosts

13. IPv6 Configuration Assignment 1
What parameters are needed for a typical IPv6 host?
IPv6 Address … Prefix + Interface ID
Prefix Length
Default Gateway Address
DNS Server Address + DNS Search List

14. IPv6 Configuration Assignment 2
How can the IPv6 host get these parameters?
Static/Manual Configuration … Infrastructure Devices
Dynamic Assignment … End-Hosts

15. Static IPv6 Configuration (Win 7)

16. Static IPv6 Configuration (Win 7)

17. Static IPv6 Configuration (Win 7)

18. Static IPv6 Configuration (Win 7)

19. Static IPv6 Configuration (Win 7)

20. Static IPv6 Configuration (Win 7)

21. Static IPv6 Configuration (Win 7)

22. Static IPv6 Configuration (Linux)
Temporary
configuration

23. Static IPv6 Configuration (Linux)
Debian-based: /etc/network/interfaces
RedHat-based: /etc/sysconfig/network-scripts/ifcfg-eth0
Permanent
configuration

24. Static IPv6 Configuration (Cisco)
Router(config)#ipv6 unicast-routing Router(config)#int Gi0/1 Router(config-if)#ipv6 addr 2001:718:803:1::1/64 Router(config-if)#no shutdown Router#show ipv6 int brief GigabitEthernet0/1 [up/up] FE80::32E4:DBFF:FEEB:5B :718:803:1::1 Router#show ipv6 route C 2001:718:803:1::/64 [0/0] via GigabitEthernet0/1, directly connected L 2001:718:803:1::1/128 [0/0] via GigabitEthernet0/1, receive L FF00::/8 [0/0] via Null0, receive
Router#show ipv6 int gi0/1 GigabitEthernet0/1 is up, line protocol is up IPv6 is enabled, link-local address is FE80::32E4:DBFF:FEEB:5B21 No Virtual link-local address(es): Global unicast address(es): 2001:718:803:1::1, subnet is 2001:718:803:1::/64 Joined group address(es): FF02::1 FF02::2 FF02::1:FF00:1 FF02::1:FFEB:5B21
EUI-64 possible as well … R(config-if)# ipv6 addr 2001:718:803:1::/64 eui-64

25. Troubleshooting ping Loopback ping own NIC ping Default-GW
ping DNS-Servers
traceroute
Windows: ping, tracert
Linux: ping6, traceroute6

26. Lab 1
Dual Stack (IPv4 + IPv6) – Static configuration

27. Dynamic Assignment Stateful DHCPv6
DHCPv6 Solicit
DHCPv6 Advertise
DHCPv6 Request
DHCPv6 Reply
DUID (DHCP Unique Identifier)
Problem with the Default-Gateway
SLAAC = StateLess Address AutoConfiguration
Stateless DHCPv6
DNS Servers + Search List

28. SLAAC End host needs: RA sent: a) periodically, b) reply to RS
1. Prefix … ok
2. Interface ID … missing
3. Prefix length … ok
4. GW IPv6 Address … partially
5. DNS Information … missing*
RA sent: a) periodically, b) reply to RS
* RFC 6106 – DNS info inside the RA message; or Stateless DHCPv6

29. SLAAC - RS
Router Solicitation

30. SLAAC - RA
Router Advertisement

31. SLAAC – Interface ID
EUI-64

32. SLAAC – Interface ID Random Random -> EUI-64
netsh int ipv6 set global randomizeidentifiers=disabled

33. SLAAC – „Temporary IPv6 Address“
Only two addresses by now – the Global and Link Local address. Why another one?
The Temporary address is used for outgoing communication (security reasons).
How to disable the temporary address
netsh int ipv6 set privacy disabled

34. SLAAC – Default Gateway

35. Lab 2
Dual Stack (IPv4 + IPv6) – SLAAC End-Hosts

36. IPv6 Header Compared to the IPv4-Header:
longer, but simpler, fewer fields
no checksum
fixed length (40 bytes)
extension headers

37. Lab 3
IPv6 Header Analysis + Encapsulation Analysis

38. Questions

39. References
ODOM, W. CCNP ROUTE Official Certification Guide. Cisco Press, ISBN