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IPv6 Technical Overview: Address Architecture, DHCPv6 and DNS
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IPv6 Technical Overview: Address Architecture, DHCPv6 and DNS

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IPv6 technical overview presentation on address achitecture, DHCPv6 and DNS

IPv6 technical overview presentation on address achitecture, DHCPv6 and DNS

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IPv6 Technical Overview: Address Architecture, DHCPv6 and DNS IPv6 Technical Overview: Address Architecture, DHCPv6 and DNS Presentation Transcript

  • IPv6 Technical Overview: Address Architecture, DHCPv6 and DNS www.netuf.net expert network architecture, engineering deployment and training twitter: @netuf © 2011 - 2014 Network Utility Force, LLC.
  • IPv6 Address Architecture 128-bit address space 2128 possible addresses 3.4 x 1038 (340 undecillion) 340,282,366,920,939,463,374,607,431,768,211,456 addresses 128 bits allow for multi-level, hierarchical routing infrastructure 64-bit subnet prefix 64-bit interface identifier www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • Benefits of 128 bit address • Easier address management and delegation • Easier address auto-configuration • Deploy end-to-end IPsec – (NATs removed as unnecessary) www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • Hexadecimal Review ● Grouping binary bits into groups of 4. ● Each group (nibble) is assigned a hex digit value. ● Digits are the same as for decimal up to 9 ● Letters A through F are used for 10 through 15. www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC. 0000 = 0 1000 = 8 0001 = 1 1001 = 9 0010 = 2 1010 = A 0011 = 3 1011 = B 0100 = 4 1100 = C 0101 = 5 1101 = D 0110 = 6 1110 = E 0111 = 7 1111 = F Thus the 16-bit binary number: 1011 0100 1010 0111 converted to hex is: B4A7
  • IPv6 Address Syntax ● Binary 0010000000000001000011011011100000000000000000000010111100111011 0000001010101010000000001111111111111110001010001001110001011010 ● Divided on 16-bit boundaries 0010000000000001 0000110110111000 0000000000000000 0010111100111011 0000001010101010 0000000011111111 1111111000101000 1001110001011010 ● 16-bit blocks converted to hexadecimal, delimited with colons 2001:0DB8:0000:2F3B:02AA:00FF:FE28:9C5A ● Suppressing leading zeroes in each block 2001:DB8:0:2F3B:2AA:FF:FE28:9C5A www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • IPv6 Format and Header www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC. IPv6 Header Upper layer Protocol Data Unit Payload IPv6 Packet Extension Headers
  • IPv4 and IPv6 Header Comparison www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC. 40 bytes 20 bytes IPv4 IPv6 0 15 16 31 vers hlen TOS total length identification flags flag-offset TTL protocol header checksum source address destination address options and padding vers traffic class flow-label payload length next header hop limit source address destination address Removed (6) ID, flags, flag offset TOS, hlen ,header checksum Changed (3) Added (2) Expanded - total length => payload - protocol => next header - TTL => hop limit - traffic class - flow label address 32 to 128 bits
  • IPv6 Prefixes ● Always uses address/prefix-length notation Similar to CIDR Subnet prefix: 2001:DB8:0:2F3B::/64 Route prefix: 2001:DB8:3F::/48 www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • Address Types • Unicast – Address of single interface, delivery to single interface • Anycast – Address of set of interfaces, delivery to single interface within set • Multicast – Address of set of interfaces, delivery to all interfaces in set • No more broadcast • IPv6 nodes will have more than one IP address www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • Identification www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC. Address Type Identification IPv4 IPv6 Internet address classes N/A Multicast address 224.0.0.0/4 IPv6 multicast address FF00::/8 Broadcast addresses N/A Unspecified address 0.0.0.0 Unspecified address :: Loopback address 127.0.0.1 Loopback address ::1 Public IP address Global Unicast Address Private IP address Unique-local address FD00::/8 APIPA address Link-local address FE80::/64 Dotted decimal format Colon hexadecimal format Subnet mask or prefix length Prefix length notation only
  • Questions © 2011 - 2014 Network Utility Force, LLC. www.netuf.net | 404-635-6667 | info@netuf.net
  • Router Advertisements ● Router Advertisements (RA) replace dependence on DHCPv4 ○ Default router address ○ Prefix ○ Bits to tell devices how to get configuration information Provides stateful address configuration or stateless configuration settings for IPv6 hosts Managed Address Configuration (M) flag When set to 1, this flag instructs the host to use a configuration protocol to obtain stateful addresses Other Stateful Configuration (O) flag When set to 1, this flag instructs the host to use a configuration protocol to obtain other configuration settings © 2011 - 2014 Network Utility Force, LLC. www.netuf.net | 404-635-6667 | info@netuf.net
  • Neighbor Discovery ● Neighbor Discovery (ND) replaces ARP ○ Uses a much more efficient multicast process to discover link level information about other LAN devices ● ONLY ND IS REQUIRED FOR BASIC IPV6 TO WORK LOCALLY ON A LAN © 2011 - 2014 Network Utility Force, LLC. www.netuf.net | 404-635-6667 | info@netuf.net
  • DHCPv6 Components ● IPv6 hosts do not automatically configure a directly attached subnet route for a DHCPv6-assigned IPv6 address ■ On-Link flag in the Prefix Information option ● There is no Router option in DHCPv6 to assign a default router ■ Default route is configured from the RA www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • Additional DHCPv6 Components • Components of a DHCPv6 infrastructure – DHCPv6 clients – DHCPv6 servers – DHCPv6 relay agents www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • DHCPv6 Messages ● User Datagram Protocol (UDP) messages DHCPv6 clients listen on UDP port 546 DHCPv6 servers and relay agents listen on UDP port 547 ● Multicast addresses DHCPv6 servers and relay agents listen on ff02::1:2 DHCPv6 client sends messages to ff02::1:2 Relay agent forwards multicasts as unicasts to configured DHCPv6 servers www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • DHCPv6 Message Types ● Solicit ● Advertise ● Request ● Confirm ● Renew ● Rebind ● Reply ● Release ● Decline ● Reconfigure ● Information-Request ● Relay-Forward ● Relay-Reply www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • DHCPv6 Relay Agent • Node that acts as an intermediary to deliver DHCP messages between clients and servers – On the same link as the client – Listening on multicast addresses • All_DHCP_Relay_Agents_and_Servers (FF02::1:2) www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • IPv6 Router Renumbering ● New address prefixes can be introduced, old ones withdrawn ● Hosts learn prefix lifetimes and preference order from router advertisements ● Old TCP connections can survive until end of overlap ● New TCP connections use longest preferred lifetime ● Router renumbering protocol - allow domain-interior routers to learn of prefix introduction / withdrawal www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • Autoconfiguration: Plug-and-Play • Hosts generally construct addresses from RA: – subnet prefix(es) learned from periodic multicast advertisements from neighboring router(s) – interface IDs generated locally – MAC addresses : pseudo-random temporary • Other IP-layer parameters also learned from router adverts (e.g., router addresses, recommended hop limit, etc…) • Higher-layer info (e.g., DNS server and NTP server addresses) discovered by multicast / anycast-based service-location protocol, or DHCPv6 • DHCP is available www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • Stateful Message Exchange 1. A Solicit message sent by the client to locate the servers 2. An Advertise message sent by a server to indicate that it can provide addresses and configuration settings 3. A Request message sent by the client to request addresses and configuration settings from a specific server 4. A Reply message sent by the requested server that contains addresses and configuration settings www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • Questions © 2011 - 2014 Network Utility Force, LLC. www.netuf.net | 404-635-6667 | info@netuf.net
  • Why is DNS Important? • Hides intricacies of underlying network structure – Translation between symbolic names and IP addresses • Provides applications (domain name servers, mail exchangers) reverse lookups, mapping IP numbers to a name • YOU DON’T HAVE TO REMEMBER 2620:144:2D00::138 www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • Changes to DNS for IPv6 • DNS Enhancements – DNS extensions to support IP version 6 • RFC 3596 – Name to address records • AAAA record type – Address to name records • New reverse domain: IP6.ARPA www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • DNS Structure • Resource Record (RRs): Data records stored by name servers • Types of RRs: – Start of Authority (SOA): Marks the beginning of a DNS zone – Name Servers (NS): Domain name of a server in a DNS zone – Canonical Names (CNAMEs): Aliases for FQDN – Pointer (PTR): IP number to name mapping www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC.
  • DNS Extensions www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC. In Use Experimental/Deprecated AAAA record A6 and DNAME records Textual representation in PTR record Binary Labels type IP6.arpa IP6.int domain New DNS Queries •AAAA • Forward lookup (Name → IPv6 Address) A 192.134.0.49 AAAA 2001:660:3006:1::1:1 •PTR • Reverse lookup (IPv6 Address → Name) Main tree: ip6.arpa
  • Reverse Lookup www.netuf.net | 404-635-6667 | info@netuf.net © 2011 - 2014 Network Utility Force, LLC. • Reverse DNS lookups for IPv6 addresses use similarly the ip6. arpa domain – Top-Level Domain (TLD). • IPv6 address represented as a name in the ip6.arpa domain by a sequence of nibbles in reverse order • Represented as hexadecimal digits, separated by dots with the suffix .ip6.arpa IPv6: 4321:0:1:2:3:4:567:89AB.ip6.arpa B.A.9.8.7.6.5.0.4.0.0.0.3.0.0.0.2.0.0.0.1.0.0.0.0.0.0.0.1.2.3.4.IP6.ARPA
  • Questions © 2011 - 2014 Network Utility Force, LLC. www.netuf.net | 404-635-6667 | info@netuf.net
  • Brandon Ross CEO and Chief Network Architect bross@netuf.net 404-635-6667 © 2011 - 2014 Network Utility Force, LLC. Thank You www.netuf.net | 404-635-6667 | info@netuf.net