Guidelines for IP version independence in GGF specs

1. Guidelines for IP version independence in GGF specs T.Chown, J.Bound, S.Jiang Piers O’Hanlon IPv6-WG - 9th Global Grid Forum, Chicago

2. Motivation • Aid in creation of IP independent specs • Ipv4 to IPv6 transition • How to avoid IPv4 dependencies • Raises new IPv6-specific issues • To be used as checklist for all new GGF specs IPv6-WG - 9th Global Grid Forum, Chicago

3. IP Standards & Specs • IP Address representation • IPv6:128bits vs IPv4:32bits • Storage & Display of IP addresses • IPv6: 3-39 Chars, IPv4: 7-15 Chars • Use of Fully Qualified Domain Names • Literal IPv6 Addresses • In URI’s for Handles, HTTP, SIP etc • Documentation examples prefix IPv6-WG - 9th Global Grid Forum, Chicago

4. Implementation Issues • API’s for C and Java • IETF IPv6 Basic and Advanced API • Java IPv6 Support since JDK1.4 • Storage of IP addresses • Socket (sock_storage) • Addresses (in_addr, in6_addr) • Localhost references (::1,127.0.0.1) • Resolution and conversion fn’s • getnameinfo(), getaddrinfo() • DNS records: AAAA IPv6-WG - 9th Global Grid Forum, Chicago

5. Implementation Issues(2) • Parsing & display IP addresses • IPv6 addr conventions “:”, “::” • IPv4-Mapped Addr handling • IPv4 only talks to IPv6 app on dual stack • ::ffff:a.b.c.d (a.b.c.d is IPv4 addr) • IPv4-Mapped problem • Can be spoofed • Implementation complexity • Maybe deprecated IPv6-WG - 9th Global Grid Forum, Chicago

6. New features • No need for NAT • Private, local scope addr • IPv4 private e.g 10.0.0.x • Local scope IPv6 – problems • Replacement being defined • Anycast Addresses • Flow Label (IPv6 only, QoS) • Privacy extensions • Multicast • No MSDP • Link scope multicast replaces IPv4 broadcast IPv6-WG - 9th Global Grid Forum, Chicago

7. New Features (2) • Path MTU discovery (Required) 1280 • Fragmentation at end points only • Extensible Header format • DiffServ Code Point / ToS byte • Similar to IPv4 • IPsec • required in ‘full implementation’ • IP mobility • Route optimisation IPv6-WG - 9th Global Grid Forum, Chicago

8. Within Specifications • Literal addresses should use the format of RFC2732 where address:port pairs are expressed (i.e. URI’s URLs). Note RFC2396 only defines ipv4 literals 2. Fully Qualified Domain Names (FQDNs) should be used in preference to IP addresses where practical to do so. 3. IPv6 addresses may potentially be shorter or longer than IPv4 addresses when represented as a text string (three to 39 characters, as opposed to seven to 15 characters). 4. Special addresses, such as loopback/localhost (127.0.0.1 in IPv4, ::1 in IPv6), are represented differently in each protocol; use of localhost by name abstracts this difference. 5. The agreed IPv6 Documentation prefix should be used in specification documents. 6. New implications of IPv6, as outlined in Section 5, should be considered. IPv6-WG - 9th Global Grid Forum, Chicago

9. Within Implementations 1. Code should be developed to be IP-independent, not IPv4-only or IPv6-only. 2. IP-independent API’s and data structures should be used, e.g. the getnameinfo() function and addrinfo for storage. 3. Code should be modular such that future changes to the networking mechanics should be minimal. 4. Care should be given to how IPv4 or IPv6 protocols are preferred and selected when both protocols are available. 5. Applications may need to iterate (or parallelise) connection attempts using multiple different source or address combination pairs due to multi-addressing (with multiple IPv6 addresses, or IPv4 and IPv6 addresses in dual stack nodes). 6. New implications of IPv6, as outlined in Section 5, should be considered. IPv6-WG - 9th Global Grid Forum, Chicago

10. Survey of IPv4 Dependencies in GGF Specs [R.Sofia, S.Jiang, C.Bouras, D.Primpas, K.Stamos] Piers O’Hanlon IPv6-WG - 9th Global Grid Forum, Chicago

11. Methodology • Similar to IETF v6ops WG surveys • draft-ietf-v6ops-ipv4survey-xxxxxx • All possible IP dependencies • Concept and implementation • Storage and examples • Explicit dependencies • Direct impact on specs • Implicit dependencies • Indirect impact on specs IPv6-WG - 9th Global Grid Forum, Chicago

12. Typical IPv4 Dependencies • URI – URI format IPv6 RFC2732 • Handles, HTTP etc • Explicit IPv4 addresses mentioned • Examples containing IPv4 only • Reference to network entities • E.g. NAT’s – NAT-PT IPv6-WG - 9th Global Grid Forum, Chicago

13. Who • Public Comment & Approved Specs • Rute Sofia (FCCN/?) • Applications & Architecture • Professor Christos Bouras (CTI) • Data and Scheduling • Dimitris Primpas, K.Stamos (CTI) • Security • Sheng Jiang (UCL) IPv6-WG - 9th Global Grid Forum, Chicago

14. Final Specifications (GFD-X) • App Prog Models & Environ (APME) – 0/2 • Architecture (ARCH) – 0/1 • Data (DATA) – 1/2 • Grid Security (GRID SEC) – 0/3 • Info Systems & Performance (ISP) – 2/2 • Scheduling & Resource Mgmnt (SRM) – 2/4 IPv6-WG - 9th Global Grid Forum, Chicago

15. Public Comment Drafts (GWD-X) • Community Practice (GWD-C) – 0/2 • Informational (GWD-I) – 0/3 • Recommendations track (GWD-R) – 1/2 IPv6-WG - 9th Global Grid Forum, Chicago

16. Current Draft Specs (GWD-X) • App Prog Models & Environ (APME) – 1/5 • Architecture (ARCH) – 4/11 • Data (DATA) – 5/9 • Info Systems & Performance (ISP) – 2/6 • Peer-to-Peer (P2P) – 1/2 • Grid Security (GRID SEC) – 6/14 • Scheduling & Resource Mgmnt (SRM) – 1/9 IPv6-WG - 9th Global Grid Forum, Chicago

17. Summary • Surveys 73 GGF Documents • 25 (34%) had some form IPv4 dependency IPv6-WG - 9th Global Grid Forum, Chicago

18. Updates • Any comments? • Update procedure..? • A little re-organisation, corrections IPv6-WG - 9th Global Grid Forum, Chicago