IPv6 Addressing Lecture Notes PDF

IPv6 Addressing IPv6 Network Addresses © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 2 IPv4 Issues The Need for IPv6 ▪ IPv6 versus IPv4: Has a larger 128-bit address space 340 undec...

IPv6 Addressing IPv6 Network Addresses © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 2 IPv4 Issues The Need for IPv6 ▪ IPv6 versus IPv4: Has a larger 128-bit address space 340 undecillion addresses Solves limitations with IPv4 Adds enhancement like address auto- configuration. ▪ Why IPv6 is needed: Rapidly increasing Internet population Depletion of IPv4 Issues with NAT Internet of Things © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 3 IPv4 Issues IPv4 and IPv6 Coexistence ▪ Migration from IPv4 to IPv6 Techniques Dual stack - Devices Tunneling - The IPv6 Translation - Network run both IPv4 and IPv6 packet is encapsulated Address Translation 64 protocol stacks inside an IPv4 packet. (NAT64) allows IPv6-enabled simultaneously. devices to communicate with IPv4 devices. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 4 IPv6 Addressing IPv6 Address Representation ▪ IPv6 Addresses: Preferred format for IPv6 representation 128 bits in length Every 4 bits is represented by a single hexadecimal digit Hextet - unofficial term referring to a segment of 16 bits or four hexadecimal values. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 5 IPv6 Addressing Rule 1 – Omit Leading 0s ▪ In order to reduce or compress IPv6 First rule is to omit leading zeros in any hextet. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 6 IPv6 Addressing Rule 2 – Omit All 0 Segments ▪ Rule 2 – Omit All 0 Segments A double colon (::) can replace any single, contiguous string of one or more 16-bit segments (hextets) consisting of all 0s. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 7 IPv6 Addressing Rule 2 – Omit All 0 Segments Examples Compress IPv6 adresses Expand IPv6 adresses 2041:0000:140F:0000:0000:0000:875B:131B fd00:0:0:4100:: 2041:0:140F::875B:131B fd00:0000:0000:4100:0000:0000:0000:0000 fd00:2600:0000:0002:0000:0000:0000:0000 fd00:8203:0:ac00::4000:0 fd00:2600:0:2:: fd00:8203:0000:ac00:0000:0000:4000:0000 fd80:0000:0020:0000:0000:2700:0000:0002 fd80:0:20::2700:0:2 © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 8 Types of IPv6 Addresses IPv6 Address Types ▪ Three types of IPv6 addresses: Unicast- Single source IPv6 address. Multicast - An IPv6 multicast address is used to send a single IPv6 packet to multiple destinations. Anycast - An IPv6 anycast address is any IPv6 unicast address that can be assigned to multiple devices. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 9 Types of IPv6 Addresses IPv6 Prefix Length ▪ The IPv6 prefix length is used to indicate the network portion of an IPv6 address: The prefix length can range from 0 to 128. Typical IPv6 prefix length for most LANs is /64 © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 10 Unicast IPv6 Network Addresses © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 11 Types of IPv6 Addresses IPv6 Unicast Addresses Global Unicast - These are globally unique, Internet routable addresses. Link-local - used to communicate with other devices on the same local link. Confined to a single link. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 12 Types of IPv6 Addresses IPv6 Link-Local Unicast Addresses ▪ IPv6 link-local addresses: Enable a device to communicate with other IPv6-enabled devices on the same link only. Are created even if the device has not been assigned a global unicast IPv6 address. Are in the FE80::/10 range. Note: Typically, it is the link-local address of the router that is used as the default gateway for other devices on the link. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 13 IPv6 Unicast Addresses Structure of an IPv6 Global Unicast Address ▪ Currently, only global unicast addresses with the first three bits of 001 or 2000::/3 are being assigned ▪ A global unicast address has three parts: Global routing prefix - network, portion of the address that is assigned by the provider. Typically /48. Subnet ID – Used to subnet within an organization. Interface ID - equivalent to the host portion of an IPv4 address. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 14 IPv6 Unicast Addresses Static Configuration of a Global Unicast Address ▪ Router Configuration: ▪ Similar commands to IPv4, replace IPv4 with IPv6 ▪ Command to configure andIPv6 global unicast on an interface is ipv6 address ipv6- address/prefix- length © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 15 IPv6 Unicast Addresses Static Configuration of a Global Unicast Address (Cont.) ▪ Host Configuration: Manually configuring the IPv6 address on a host is similar to configuring an IPv4 address Default gateway address can be configured to match the link-local or global unicast address of the Gigabit Ethernet interface. ▪ Dynamic assignment of IPv6 addresses: Stateless Address Auto-configuration (SLAAC) Stateful DHCPv6 © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 16 IPv6 Unicast Addresses Dynamic Configuration - SLAAC ▪ Stateless Address Autoconfiguration (SLAAC): A device can obtain its prefix, prefix length, default gateway address, and other information from an IPv6 router. Uses the local router’s ICMPv6 Router Advertisement (RA) messages ▪ ICMPv6 RA messages sent Option 1 (SLAAC Only) – "I'm everything you need (Prefix, every 200 seconds to all IPv6- Prefix-length, Default Gateway)" enabled devices on the network. Option 2 (SLAAC and DHCPv6) – "Here is my information but you need to get other information such as DNS addresses from a DHCPv6 server." Option 3 (DHCPv6 Only) – "I can’t help you. Ask a DHCPv6 © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential server for all your information." 17 IPv6 Unicast Addresses Dynamic Configuration – DHCPv6 ▪ The RA Option 1: SLAAC only (this is the default) ▪ RA Option 2: SLAAC and Stateless DHCPv6: Uses SLAAC for IPv6 global unicast address and default gateway. Uses a stateless DHCPv6 server for other information. ▪ RA Option 3: Stateful DHCPv6 Uses the Routers link-local address for the default gateway. Uses DHCPv6 for all other information. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 18 IPv6 Unicast Addresses EUI-64 Process and Randomly Generated ▪ When the RA message is SLAAC or SLAAC with stateless DHCPv6, the client must generate its own Interface ID The Interface ID can be created using the EUI-64 process or a randomly generated 64- bit number ▪ An EUI-64 Interface ID is represented in binary and is made up of three parts: 24-bit OUI from the client MAC address, but the 7th bit (the Universally/Locally (U/L) bit) is reversed. The inserted 16-bit value FFFE (in hexadecimal). 24-bit Device Identifier from the client MAC address. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 19 IPv6 Unicast Addresses EUI-64 Process and Randomly Generated (Cont.) ▪ Randomly Generated Interface IDs Windows uses a randomly generated Interface ID © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 20 IPv6 Unicast Addresses Dynamic Link-Local Addresses ▪ Link-local address can be established dynamically or configured manually. ▪ Cisco IOS routers use EUI-64 to generate the Interface ID for all link-local address on IPv6 interfaces. ▪ Drawback to using the dynamically assigned link-local address is the long interface ID, therefore they are often configured statically. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 21 IPv6 Unicast Addresses Static Link-Local Addresses ▪ Manual Configuration of the link-local address allows the creation of a simple, easy to remember address. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 22 IPv6 Unicast Addresses Verifying IPv6 Address Configuration ▪ The commands to verify IPv6 configuration are similar to IPv4 show ipv6 interface brief show ipv6 route ▪ The ping command for IPv6 is identical to the command used with IPv4, except that an IPv6 address is used. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 23 Multicast IPv6 Network Addresses © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 24 IPv6 Multicast Addresses Assigned IPv6 Multicast Addresses ▪ There are two types of IPv6 multicast addresses: Assigned multicast - reserved multicast addresses for predefined groups of devices Solicited node multicast ▪ Two common IPv6 assigned multicast groups: FF02::1 All-nodes multicast group – This is a multicast group that all IPv6-enabled devices join. Similar to a broadcast in IPv4 FF02::2 All-routers multicast group – This is a multicast group that all IPv6 routers join. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 25 IPv6 Multicast Addresses Solicited-Node IPv6 Multicast Addresses ▪ Solicited-node multicast address: Mapped to a special Ethernet multicast address Allows Ethernet NIC to filter frame on destination MAC. ▪ Solicited-Node multicast addresses are used in Neighbor Discovery Protocol for obtaining the layer 2 link-layer addresses of other nodes. ▪ Similar to the all-nodes multicast address, ▪ Automatically created when the global unicast or link-local unicast addresses are assigned ▪ Created by combining a special FF02::1:FF/104 prefix with the right-most 24 bits of its unicast address. FF02:0:0:0:0:1:FF00:0 © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 26 IPv6 Multicast Addresses Solicited Node IPv6 Multicast Addresses © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 27