Lecture 2 - Internet evolution (part 2)

1. Lecture 2- Internet evolution (part 2) D.Sc. Arto Karila Helsinki Institute for Information Technology (HIIT) arto.karila@hiit.fi M.Sc. Mark Ain Helsinki Institute for Information Technology (HIIT) mark.ain@hiit.fi T-110.6120 – Special Course in Future Internet Technologies

2. Evolutionary approaches Architectural • DNS (~1982) • EGP (precursor to BGP, ~1982) • TCP congestion control (mid-late 1980’s) • CIDR (~1993) • NAT (early 1990’s) • IPv6 (first RFC 1995, Internet standard 1998) • IPSEC (1995) • Mobile IP (~1996) • MPLS (~1996) • DiffServ/ IntServ (~1998) • HIP (~1999, first RFC 2006) • BGPSec (mid 2000s) • DNSSec (~2004, first deployed at root level ~2010)

3. Network Address Translation (NAT) – 4 types • Problem: address space exhaustion

4. Network Address Translation (NAT) – 4 types

5. Network Address Translation (NAT) – 4 types

6. Network Address Translation (NAT) – 4 types  NAT is ugly, breaks E2E… but it works.

7. IPv6 • Problem: address space exhaustion • IPv6 was born in 1995 after long work • There are over 30 IPv6-related RFCs • The claimed improvements in IPv6 are: • Large 128-bit address space • Stateless address auto-configuration • Multicast support • Mandatory network layer security (IPSEC) • Simplified header processing by routers • Efficient mobility (no triangular routing) • Extensibility (extension headers) • Jumbo packets (up to 4 GB)

8. IPv6 • Major operating systems and many ISPs support IPv6 • The use of IPv6 is slowly increasing in Europe and North America but more rapidly in Asia • In China, CERNET 2 runs IPv6, interconnecting 25 points of presence in 20 cities with 2.5 and 10 Gbps links • IPv6 really only solves the exhaustion of Internet address space

9. IPv6 ? Planned Actual

10. IPSec • Problem: security • IPSec is the IP-layer security solution of the Internet to be used with IPv4 and IPv6 • Authentication Header (AH) only protects the integrity of an IP packet • Encapsulating Security Payload (ESP) also ensures confidentiality of the data • IPSec works within a Security Association (SA) set up between two IP addresses • ISAKMP (Internet Security Association and Key Management Protocol) is a very complicated framework for SA mgmt

11. Original IPv4 Header Security Parameter Index (SPI) ESP Header Sequence Number Coverage of Authentication UDP/TCP Header ESP Payload Coverage ofConfidentiality Data Padding Pad Len Next Hdr ESP Trailer Authentication Data Encapsulating Security Payload (IPv4)

12. Original IPv6 Header Hop-by-Hop Extensions Security Parameter Index (SPI) ESP Header Sequence Number Coverage of Authentication End-to-End Extensions UDP/TCP Header ESP Payload Coverage ofConfidentiality Data Padding ESP Trailer Authentication Data Encapsulating Security Payload (IPv6)

13. Mobile IPv4 • Problem: mobility • Basic concepts: • Mobile Node (MN) • Correspondent Node (CN) • Home Agent (HA) • Foreign Agent (FA) • Care-of-Address (CoA) • The following can be problematic: • Firewalls and ingress filtering • Triangular routing

14. DELAY! Mobility Example:Mobile IP Triangular Routing Ingress filtering causes problems for IPv4 (home address as source), IPv6 uses CoA so not a problem . Solutions: (reverse tunnelling) or route optimization Correspondent Host Foreign agent left out of MIPv6. No special support needed with IPv6 autoconfiguration Foreign Agent Home Agent Care-of-Address (CoA) Mobile Host • Source: Professor Sasu Tarkoma

15. Ingress Filtering Packet from mobile host is deemed "topologically incorrect“ (as in source address spoofing) Correspondent Host Home Agent • With ingress filtering, routers drop source addresses that are not consistent with the observed source of the packet • Source: Professor Sasu Tarkoma

16. DELAY! Reverse Tunnelling Firewalls and ingress filtering no longer a problem Two-way tunneling leads to overhead and increased congestion Correspondent Host Router Home Agent Mobile Host Care-of-Address (CoA) • Source: Professor Sasu Tarkoma

17. Mobile IPv6 Route Optimization CH sends packets using routing header Correspondent Host First, a Return Routability test to CH. CH sends home test and CoA test packets. When MH receives both, It sends the BU with the Kbm key. Router Secure tunnel (ESP) Home Agent MH sends a binding update to CH when it receives a tunnelled packet. Mobile Host • Source: Professor Sasu Tarkoma

18. Differences btw MIPv6 and MIPv4 • In MIPv6 no FA is needed (no infrastructure change) • Address auto-configuration helps in acquiring CoA • MH uses CoA as the source address in foreign link, so no problems with ingress filtering • Option headers and neighbor discovery of IPv6 protocol are used to perform mobility functions • 128-bit IP addresses help deployment of mobile IP in large environments • Route optimization is supported by header options • Source: Professor Sasu Tarkoma

19. Extension Headers CN to MN MN to CN Upper Layer headers Data MH Mobility Header MH Type in Mobility Header: Binding Update, Binding Ack, Binding Err, Binding refresh MN, HA, and CN for Binding Source: Chittaranjan Hota, Computer Networks II lecture 22.10.2007

20. (G)MPLS • Problems: scalable transport, QoS, resource usage, business incentives etc. • (Generalized) Multi-Protocol Label Switching • Layer 2.5 protocol • High-performance transport of any layer 3 protocol over any layer 2 data link over any layer 1 medium • Routing via short path labels (path switching) • Layer 2 and layer 3 services (e.g. PtP and PtMP VPN) • Routing implemented in hardware (i.e. switching); much faster than IP longest-prefix matching

21. (G)MPLS

22. QoS • Problem: need better traffic control, satisfy business incentives, better services etc.

23. DiffServ • Differentiated Services (DiffServ, RFC 2474) redefines the ToS octet of the IPv4 packet or Traffic Class octet of IPv6 as DS • Allows operators to control treatment of packets but does not guarantee any particular level of service or policy adherence across network boundaries. • The first 6 bits of the DS field are used as Differentiated Services Code Point (DSCP) defining the Per-Hop Behavior of the packet • DiffServ is stateless (like IP) and scales • Service Profiles can be defined by ISP for customers and by transit providers for ISPs • DiffServ is very easily deployable and could enable well working VoIP and real-time video • Unfortunately, it is not used between operators

24. IntServ • Integrated Services • Unlike DiffServ, IntServ reserves network resources and attempts to guarantee conditions of network flow end-to-end • However, the process is complex, resource intensive, and requires supportive cooperating routers across all AS’s from source to sink.

25. HIP • Problems: mobility, security, multihoming, IPv4/IPv6 interoperation etc. • Host Identity Protocol (HIP, RFC4423) defines a new global Internet name space • The Host Identity name space decouples the name and locator roles, both of which are currently served by IP addresses • The transport layer now operates on Host Identities instead of IP addresses • The network layer uses IP addresses as pure locators (not as names or identifiers)

26. HIP Architecture

27. HIP • HIs are self-certifying (public keys) • HIP is a fairly simple technique based on IPSEC ESP and HITs (128-bit HI hashes) • HIP is ready for large-scale deployment • See http://infrahip.hiit.fi for more info

28. I1 HITI, HITR or NULL R1 HITI, [HITR, puzzle, DHR, HIR]sig I2 [HITI, HITR, solution, DHI,{HII}]sig R2 [HITI, HITR, authenticator]sig ESP protected TCP/UDP, no explicit HIP header Base exchange • Based on SIGMA family of key exchange protocols Select precomputed R1. Prevent DoS. Minimal state kept at responder! Does not protect against replay attacks. Initiator Responder standard authenticated Diffie-Hellman key exchange for session key generation solve puzzle verify, authenticate, replay protection User data messages draft-ietf-hip-base-02.txt, draft-jokela-hip-esp-00.txt

29. HIP Mobility • Mobility is easy – retaining the SA for ESP

30. IPv4 access Internet network WWW Proxy HIP CN HIP MN Music Server HIP in Combining IPv4 and IPv6 • An early demo seen at L.M. Ericsson Finland (source: Petri Jokela, LMF)

31. BGPSec and DNSSec • Problem: security (within two critical architectural solutions) • BGP Security Extensions: • Authentication of inter-AS BGP data via Resource Public Key Infrastructure (RPKI) i.e. digital signatures • Does NOT provide confidentiality or guaranteed availability • Provides limited protection against certain mis-origination attacks • Not widely implemented

32. BGPSec and DNSSec • DNS Security Extensions: • Authentication and integrity (of DNS query results) via digital signatures • Does NOT provide confidentiality or guaranteed availability • Protects against e.g. cache poisoning and other forgeries • Not widely implemented

33. Key limitations, solutions, underlying ossifications

34. Evolutionary approaches Application-level • Scalable content delivery • DHTs (~2001) • P2P networks • CDNs (e.g. Akamai) • Security (confidentiality, anonymity, authentication etc.) • Asymmetric crypto (e.g. RSA ~1977 or ~1973, DH ~1976) • PGP (~1991) • SSL/TLS (mid-1990’s, late-1990’s) • PKI (1990’s) • VPNs E.g. PPTP (~1999) • Wireless security e.g. WPA/WPA2/EAP (late 1990’s and beyond) • Tor (mid 2000’s) • Cloud computing

35. Distributed Hash Table (DHT) • Distributed Hash Table (DHT) is a service for storing and retrieving key-value pairs • There is a large number of peer machines • Single machines leaving or joining the network have little effect on its operation • DHTs can be used to build e.g. databases (new DNS), or content delivery systems • BitTorrent is using a DHT • The real scalability of DHT is still unproven • All of the participating hosts need to be trusted (at least to some extent)

36. DHT • The principle of Distribute Hash Table (source: Wikipedia)

37. Overlay Routing • In overlay routing the topology is formed over an underlying (usually IP) network • DHTs are examples of overlay routing • DHT techniques can be utilized e.g. in implementing non-hierarchical rendezvous • An example of DHT-based solutions is the Content Addressable Network (CAN) • CAN is based on a d-dimensional Cartesian space, each node having a coordinate zone that it is responsible for

38. CAN • A two-dimensional example

39. Chord Ring • Greedy forwarding (cmp w/ ROFL)

40. Pastry DHT • An example with hexadecimal identifiers

41. P2P networks & CDNs • Napster, Gnutella, BitTorrent (also utilizes DHT) etc. • Akamai CDN

42. Security • Confidentiality, anonymity, authentication etc. • Asymmetric crypto (e.g. RSA ~1977 or ~1973, Diffie-Hellman ~1976) • PGP (~1991) • SSL/TLS (mid-1990’s, late-1990’s) • PKI (1990’s) • VPNs e.g. PPTP (~1999) • Wireless security e.g. WPA/WPA2/EAP (late 1990’s and beyond) • Tor (mid 2000’s)

43. Cloud computing • Computing resources are delivered via the network • “x”aaS i.e. “x” as a service • E.g. software, storage, processing etc. • Goal is to achieve resourcefulness and efficiency via computing economies of scale • Examples: • Amazon, Apple, Google etc.

44. For next week… • READ (lecture 3): • M. Handley. 2006. Why the Internet only just works. BT Technology Journal 24, 3 (July 2006), 119-129. DOI=10.1007/s10550-006-0084-z http://dx.doi.org/10.1007/s10550-006-0084-z • READ (lecture 4): • Van Jacobson, Diana K. Smetters, James D. Thornton, Michael F. Plass, Nicholas H. Briggs, and Rebecca L. Braynard. 2009. Networking named content. In Proceedings of the 5th international conference on Emerging networking experiments and technologies (CoNEXT '09). ACM, New York, NY, USA, 1-12. DOI=10.1145/1658939.1658941 http://doi.acm.org/10.1145/1658939.1658941

45. Thank you for your attention! Questions? Comments?