IP version 6. The newest IP version. Karst Koymans. Informatics Institute University of Amsterdam. (version 17.5, 2017/11/10 13:19:24)

Transcription

1 IP version 6 The newest IP version Karst Koymans Informatics Institute University of Amsterdam (version 17.5, 2017/11/10 13:19:24) Tuesday, November 7, 2017 Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

2 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

3 Rationale Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

4 Rationale Why IP version 6 should be used Many more addresses Only 4 times as many bits (4 32 = 128) Address space grows with a factor /2 32 = 2 (128 32) = 2 96 Autoconfiguration Stateless Stateful (DHCPv6) Security Built-in IPSEC Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

5 Rationale Why IP version 6 should be used (continued) Optimized headers Fixed length (40 bytes) Extension header mechanism Mobility Direct end to end communication No NAT needed End-to-end principle could be reinstated but smart or intelligent middleboxes will interfere Software defined networking (SDN) possibly enemy of end-to-end Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

6 Rationale Why IP version 6 might be used QoS Flowlabel 1 present in the standard header Hierarchical routing Nothing new with respect to IPv4 Risk of tunnel mess because of IPv6-in-IPv4 transition scenario But tunnels are more and more replaced by native 2 access 1 The An IPv4 Flowlabel Option Internet-Draft tries to establish an IPv4 flowlabel option since 2002 (version 26 of August 6, 2017) 2 The IPv6-Internet is a reality for many users since World IPv6 Day on June 8, 2011 and World IPv6 Launch on June 6, 2012 Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

7 IPv6 addressing Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

8 IPv6 addressing IPv6 address space and notation Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

9 IPv6 addressing IPv6 address space and notation IPv6 addresses IP version bit addresses 4 times as many bits as in IPv times as many possible addresses Much more hierarchical addressing This is absolutely necessary because of the huge address space size of IPv6 Still discussions about what is the right sizing (March 2011), see RFC 6177 (BCP 157; IPv6 Address Assignment to End Sites ) Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

10 IPv6 addressing IPv6 address space and notation Remember: IPv4 address notation IPv4 address notation IP address Subnet mask (or sometimes) ( ) Network /26 Broadcast Mixed notation /26 Host and network in one notation Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

11 IPv6 addressing IPv6 address space and notation IPv6 address notation IPv6 address notation IPv6 address Short form Network Mixed notation 2001:0610:0158:bad0:0000:0000:0000: :610:158:bad0::1 2001:610:158:bad0::/ :610:158:bad0::1/64 8 blocks of 4 nibbles (hex digits), totaling 128 bits Leading zeroes in blocks may be skipped Blocks of all zeroes may be replaced by :: (once!, why?) No broadcasts (but multicasts), no subnet masks, only prefixes See RFC 4291: IP Version 6 Addressing Architecture Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

12 IPv6 addressing IPv6 address space and notation Allocated address space Top level allocations ::/8 Special-purpose 100::/8 Special-purpose 2000::/3 Global unicast fc00::/7 Unique local unicast fe80::/10 Link-local (Link-scoped) unicast ff00::/8 Multicast Exercise Write down the unallocated parts with as much aggregation as possible Explain and improve ipv6-address-space/ipv6-address-space.xhtml Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

13 IPv6 addressing Special-purpose space Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

14 IPv6 addressing Special-purpose space Special-purpose addresses Special-purpose addresses ::/128 Unspecified address ::1/128 Localhost address ::a.b.c.d/128 (from ::/96) IPv4-compatible addresses ::ffff:a.b.c.d/128 (from ::ffff:0:0/96) IPv4-mapped addresses 64:ff9b::/96 Well-known prefix 100::/64 Discard-only address block a.b.c.d is IPv4 address in decimal IPv4-compatible addresses were used for automatic tunneling (now deprecated) IPv4-mapped addresses may be used by IPv6-only applications to communicate with IPv4-only hosts (never seen on the wire) Algorithmic translation for IPv4/IPv6 now uses the well-known prefix Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

15 IPv6 addressing Unicast space Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

16 IPv6 addressing Unicast space Global unicast space (1) Global unicast addresses (allocated before 2006) 2001::/16 First RIR space 2002::/16 6to4 space 3ffe::/16 6bone space (returned to IANA, see RFC 5156) 5f00::/8 a 6bone space (returned to IANA) a This is a subprefix of 4000::/3, which is part of the fully reserved 4000::/2 The RIR (Regional Internet Registries) are: RIPE NCC, ARIN, APNIC, LACNIC, AfriNIC 6to4 is one of the transition mechanisms Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

17 IPv6 addressing Unicast space Global unicast space (2) Recent (2006) large chunks 2400::/12 APNIC 2600::/12 ARIN 2800::/12 LACNIC 2a00::/12 2c00::/12 RIPE NCC AfriNIC ipv6-unicast-address-assignments/ Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

18 IPv6 addressing Unicast space IANA blocks IANA blocks inside 2001::/ ::/23 IETF Protocol Assignments 2001::/32 (from 2001::/23) TEREDO 2001:2::/48 a Benchmarking 2001:4:112::/48 AS112-DNAME b 2001:20::/28 ORCHIDv2 2001:db8::/32 Documentation a The RFC mistakenly talks about 2001:200::/48 b RFC Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

19 IPv6 addressing Unicast space Anycast addresses Allocated from (Global) unicast space One anycast address has been required from the very beginning Subnet-router anycast For each subnet the address with all Interface ID bits set to zero Each IPv6 router should configure this address but it is not always implemented (officially deprecated? 3 ) It is useful to be able to find from the outside 4 the nearest router connected to a subnet 3 See IPv6 Subnet Anycast Deprecated 4 What happens from the inside? Should it also be used on the link local subnet? Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

20 IPv6 addressing Unicast space Local or private space (fe80::/9, fc00::/7) fe80::/10 (Link-local addresses) Restricted in scope to a single link (prefix fe80::/64) Address reuse possible on other link fec0::/10 (Site-local addresses; deprecated) Used within a site (what is a site?) Corporate mergers possible with GUSL (Sic!) Globally Unique Site-locals are deprecated fc00::/7 (Unique local unicast; replaces Site-local) Subnets typically look like fdrr:rrrr:rrrr:ssss::/64 (see RFC 4193) Local bit L (eighth bit) is 1; fc00::/8 is reserved rr:rrrr:rrrr is random and ssss is an assigned subnet id Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

21 IPv6 addressing Multicast Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

22 IPv6 addressing Multicast Multicast space See RFC 4291 ff00::/8 (NOT ff::/8!) Multicast address bits 8 bits ones ( ) 4 bits flag (0RPT) T (1: transient; 0: permanent) P (1: prefix-owned; 0: not prefix-owned); see RFC 3306 R (1: RP embedded; 0: no RP embedded); see RFC bits scope 112 bits multicast group id 5 5 Under further discussion, see RFC 7371, September 2014 Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

23 IPv6 addressing Multicast Multicast Scope Scope Bits Meaning Reserved Interface-local Link-local Admin-local Site-local Organization-local e 1110 Global f 1111 Reserved Others - Unassigned Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

24 IPv6 addressing Multicast Pre-defined multicast addresses Purpose Address Scope All nodes ff02::1 6 Link-local All routers ff02::2 Link-local All routers ff05::2 Site-local Solicited-Node ff02::1:ffxx:xxxx 7 Link-local 6 Why does ping6 ff02::1 not work? What does work? 7 xx:xxxx are the low order 24 bits of each unicast or anycast address which this host has configured on the interface under consideration. This multicast address is used in Neighbor Solicitation. Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

25 IPv6 addressing Addressing hierarchy Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

26 IPv6 addressing Addressing hierarchy 2001::/16 Hierarchy /16 RIR space (from IANA) /23 Basic allocation size /32 ISP allocations (from RIR) /35 Old ISP allocations /48 Customer allocations (from ISP) /56, /60 Consumer allocations /64 IPv6 subnet (inside customer network) In recent years a shift is seen to larger prefixes /12 for the five RIRs Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

27 IPv6 addressing Addressing hierarchy Addressing in Internet Exchanges (AMS-IX) Until early 2011 AMS-IX has been using SURFnet address space (2001:610:140::/48) BIT address space (2001:7b8:200::/48) Current (2012) scheme 2001:7f8:1::/48 AMS-IX (peering LAN) from 2001:7f8::/29 is a Block for (direct) RIR assignments to network operators 2001:67c:1a8::/48 AMS-IX (office LAN) from 2001:678::/29 is a Block for (direct) RIR assignments to network operators All assignments are from the 2001:600::/23 RIPE block Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

28 Neighbor Discovery Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

29 Neighbor Discovery Neighbor Discovery Protocol (NDP) IPv6 does not use ARP IPv6 does use ICMPv6 to discover or apply Address and status of neighbours Properties of networks, prefixes and routers Duplicate Address Detection (DAD) Neighbour Unreachability Detection (NUD) Extensive use of multicast Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

30 Neighbor Discovery ICMPv6 types for NDP ICMPv6 types for NDP 133 Router Solicitation 134 Router Advertisement 135 Neighbor Solicitation 136 Neighbor Advertisement 137 Redirect Message Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

31 IPv6 packet formats Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

32 IPv6 packet formats IPv6 header Vers. Traffic Class Flowlabel Payload Length Next Header Hop Limit Source Address (16 bytes) Destination Address (16 bytes) Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

33 IPv6 packet formats IPv6 header fields IPv6 header fields Version 6 Traffic Class Flowlabel Payload Length Next Header Hop Limit Source Address Destination Address Type of Service management Identify flows with special requirements Including extension headers Type of following header Forwarding count and loop protection IPv6 address of sender IPv6 address of recipient Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

34 IPv6 packet formats Next Header Protocol type Header types Number Name Meaning 0 HOPOPT Hop-by-hop Option 6 TCP Upper layer Transmission Control 17 UDP Upper layer User Datagram 41 IPv6 IPv6 (in IPv6) 43 IPv6-Route Routing Header 44 IPv6-Frag Fragment Header Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

35 Next Header protocol type Header types (continued) Number Name Meaning 50 ESP Encap Security Payload 51 AH Authentication Header 58 IPv6-ICMP ICMP for IPv6 59 IPv6-NoNxt No Next Header a 60 IPv6-Opts Destination Options a This is for instance used by Teredo bubble packets See

36 IPv4 to IPv6 transition Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

37 IPv4 to IPv6 transition General ideas Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

38 IPv4 to IPv6 transition General ideas A simple and direct transition scenario Clients dual stack Servers (services) IPv4 xor IPv6 Killer application IPv6 only Networks completely independent Configured tunnels only if no native connectivity is available Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

39 IPv4 to IPv6 transition General ideas Older IETF transition technologies (around 2000) Clients and servers dual stack Stateless IP/ICMP Translation (SIIT) RFC 2765 (Feb 2000) Bump in the Stack (BIS) RFC 2767 (Feb 2000) IPv6 Tunnel Broker RFC 3053 (Jan 2001) SOCKS-based IPv6/IPv4 Gateway RFC 3089 (Apr 2001) Transport Relay Translator (TRT) RFC 3142 (Jun 2001) An implementation of NA(P)T-PT (deprecated since RFC 4966) Makes use of DNS_ALG (RFC 2694) Bump in the API (BIA) RFC 3338 (Oct 2002) Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

40 IPv4 to IPv6 transition General ideas Current (2013) IETF transition technologies Clients and servers dual stack 6rd RFC 5569 (Jan 2010), 5969 (Aug 2010) IPv6 Rapid Deployment, using 6to4 within ISP network IP/ICMP Translation (derived from SIIT) RFC 6145 (Apr 2011) Dual-Stack Hosts Using Bump-in-the-Host (BIH) RFC 6535 (Feb 2012) NAT64 and DNS64 RFC 6146, 6147 (Apr 2011) DS-Lite (Dual-Stack Lite) RFC 6333 (Aug 2011), RFC 7335 (Aug 2014) The service provider network is IPv6 only Uses IPv4-in-IPv6 tunnels and Carrier Grade NAT (CGN) for IPv4 6to4 Do not confuse with 6in4 or 6over4 ISATAP and Teredo Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

41 IPv4 to IPv6 transition NAT64 Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

42 IPv4 to IPv6 transition NAT64 Addresses used in IPv4/IPv6 Translation Framework for IPv4/IPv6 Translation (RFC 6144, April 2011) IPv4-embedded addresses IPv6 addresses containing IPv4 addresses IPv4-converted addresses Used to represent IPv4-only hosts inside an IPv6-only network Assigned to the IPv6-side of an IPv4/IPv6 translator/gateway IPv4-translatable addresses Used to represent IPv6-only hosts inside an IPv4-only network Assigned to an IPv6-only host Only works with a stateless IPv4/IPv6 translator/gateway Embedded IPv4 address is assigned to the IPv4-side of an IPv4/IPv6 translator/gateway Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

43 IPv4 to IPv6 transition NAT64 Format of IPv4-embedded Addresses IPv6 Addressing of IPv4/IPv6 Translators RFC 6052, October 2010 Prefix IPv4 address Suffix Prefix length can be 32, 40, 48, 56, 64 or 96 The Well-known prefix (WKP 8 ) 64:ff9b::/96 is one option Other options are network specific prefixes (NSPs) Bits should all be set to 0 for compatibility with the EUI-64 9 universal bit The IPv4 address wraps around bits 64-71, if necessary The suffix completes the IPv6 address and is reserved (all 0 s) 8 Only in a stateful scenario without IPv4-translatable addresses 9 This will be explained in the Layer2 lecture Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

44 IPv4 to IPv6 transition NAT64 How do IPv6 (only) clients reach IPv4 (only) servers? It is one big NAT scheme RFC 6145 (April 2011), RFC 6791 (November 2012) IP/ICMP Translation Algorithm Header translation IPv4 IPv6 RFC 6146 (April 2011) Stateful NAT64: Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers Uses algorithmic (4 6) and table based (6 4) translation RFC 6147 (April 2011) DNS64: DNS Extensions for Network Address Translation from IPv6 Clients to IPv4 Servers Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

45 IPv4 to IPv6 transition ISATAP, 6to4 and Teredo Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

46 IPv4 to IPv6 transition ISATAP, 6to4 and Teredo Windows XP SP1 choice ISATAP (RFC 5214) For intra domain connectivity Was once automatically enabled (in XP) when IPv6 was enabled 6to4 (RFC 3056) For inter domain connectivity Was once automatically enabled (in XP) when IPv6 was enabled ISATAP + 6to4 == a possible security nightmare Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

47 IPv4 to IPv6 transition ISATAP, 6to4 and Teredo ISATAP Intra-Site Automatic Tunnel Addressing Protocol PREFIX:0:5efe:a.b.c.d PREFIX (64 bits) can be (link) local or global 0:5efe (32 bits) is an ISATAP constant Related to the IANA OUI 00:00:5e (RFC 7042) a.b.c.d (32 bits) is a public or private IPv4 address Uses IPv4 encapsulation inside the domain as data link layer Default gateway should be a full blown IPv6 router Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

48 IPv4 to IPv6 transition ISATAP, 6to4 and Teredo 6to4 Everybody with a public IPv4 address a.b.c.d owns an IPv6 site 2002:a.b.c.d::/48 This notation is illegal, but practical Uses normal IPv6 routing inside its prefix A full mesh of IPv4 encapsulated point to point links connect all 6to4 routers The 6to4 router acts as a default gateway within 2002:a.b.c.d::/48 A 6to4 relay is a 6to4 router that connects 6to4 space to native IPv6 space A 6to4 relay advertises 2002::/16 towards native IPv6 space A 6to4 relay uses a well-known IPv4 anycast address ( ) from /24 to reach nearest relay as 2002:c058:6301:: Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

49 6to4 in a picture Source:

50 ISATAP+6to4 Source: Microsoft Technet

51 IPv4 to IPv6 transition ISATAP, 6to4 and Teredo Teredo RFC 4380, 5991, 6081 Teredo Navalis is a shipworm 6to4 equivalent for end user nodes Works through NAT and uses UDPv4 for transport Uses a Teredo Server to determine NAT-type Uses the 2001::/32 prefix 2001:0000:ssss:ssss:ffff:pppp:cccc:cccc is the IPv6 address used s: Teredo Server; c: Teredo Client (obscured public side NAT address) f: Teredo Flags; p: obscured public side NAT UDP tunnel port Uses a Teredo Relay as a gateway to reach IPv6-hosts Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

52 DNS issues Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

53 DNS issues DNS AAAA record Just like A record A6 record (hierarchical; historic) PTR record Inside ip6.arpa. (ip6.int. has been deprecated) Based on nibbles as labels Labels are strings of length 1 from {0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f} DNAME (Domain CNAME) Bitstring labels (deprecated) Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

54 DNS issues DNS over IPv6 Implemented since BIND version 9 Root servers partly IPv6 enabled since February 2008 Not IPv6 enabled (tested ): e, g NASA, DISA They are now ( ) Many DNS servers use and serve IPv6 (tested ) ns1.os3.nl 2001:610:158:960::66 ns.ripe.net ns3.surfnet.nl 2001:67c:e0::6 2001:610:0:800c:195:169:124:71 Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

55 Application, protocol and programming support Outline 1 Rationale 2 IPv6 addressing IPv6 address space and notation Special-purpose space Unicast space Multicast Addressing hierarchy 3 Neighbor Discovery 4 IPv6 packet formats 5 IPv4 to IPv6 transition General ideas NAT64 ISATAP, 6to4 and Teredo 6 DNS issues 7 Application, protocol and programming support Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

56 Application, protocol and programming support IPv6 applications and protocols Many protocols can be used, often unaltered, with IPv6 ftp, ssh, telnet, smtp, whois, domain, tftp, finger, http, pop3, nntp, ntp, netbios-*, imap, irc, ldap, login, lpr, rsync, Many OSs IPv6 ready Windows XP/Vista/7/8/10, MacOS X, Linux, *BSD Many routers are IPv6 ready Home routers are the main exception, but this is improving The IPv4 address pool is depleted everywhere, except AfriNIC AfriNIC expected to run out of IPv4 addresses in 2018 Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57

57 Application, protocol and programming support IPv6 programming Changes in library calls Replace inet_addr(), inet_aton() and inet_ntoa() by inet_pton() and inet_ntop() Replace gethostbyname(), gethostbyaddr(), by getaddrinfo() and its inverse getnameinfo() Library calls and underlying structures are not backwards compatible but not too hard to change in a well written program The basics of sockets programming doesn t change Karst Koymans (UvA) IP version 6 Tuesday, November 7, / 57