HAIR: Hierarchical Architecture for Internet Routing Re-Architecting the Internet ReArch 09 Wolfgang Mühlbauer ETH Zürich / TU Berlin wolfgang.muehlbauer@tik.ee.ethz.ch Anja Feldmann Luca Cittadini Randy Bush Olaf Maennel Deutsche Telekom Università Internet Initiative Loughborough Labs / TU Berlin Roma Tre Japan University ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 1
Re-Architecting Internet Routing 300000 Routing problems: 250000 routing table growth high update rates 200000 address shortage 150000 mobility 100000 multi-homing traffic engineering 50000 lack of security 0... years Clean-slate approach: assume we could start from scratch ideas may be incrementally applicable to current Internet Our work: Hierarchical Architecture for Internet Routing (HAIR) active BGP entries 2001 2002 2003 2004 2005 2006 2007 2008 ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 2
Outline 1 Related Work 2 Architecture 3 Evaluation 4 Conclusion ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 3
Outline 1 Related Work 2 Architecture 3 Evaluation 4 Conclusion ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 4
Related Work LISP addressing: separate locators (RLOC) identifiers (EID) packet forwarding: map EID to RLOC tunnel packet through core based on RLOC multihoming easier routing table size CORE Tunnel router RLOC 1 EDGE shim6 multihoming for IPv6-enabled sites hosts control which locator is used HLP, HIT, and many others EID 1 RLOC 1/RLOC 2 tunnel Tunnel router RLOC 2 Tunnel router RLOC 3 EID 2 RLOC 3 ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 5
Clean-Slate: Design Choices Separation of locators/identifiers (LOC/ID split)? no: current Internet yes: LISP Flat/structured namespaces for LOCs and IDs? flat: Routing On Flat Labels (ROFL), SIGCOMM 06 structured: current Internet Host- or network-based solution? host-based: Shim6, no state in the network network-based: LISP, mapping done at tunnling router... ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 6
Outline 1 Related Work 2 Architecture 3 Evaluation 4 Conclusion ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 7
HAIR: Key Ideas 1 Separation of locator/identifier function of IP address 2 Use of hierarchical routing and mapping system 3 Edge-based: if possible transfer tasks to edge hosts, keep network simple ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 8
HAIR: Hierarchical Routing Why hierarchical? to provide scalability graph theory Leverage Internet hierarchy e.g., 3 levels: core: large transit provider intermediate: small providers edge: access networks, LAN ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 9
HAIR: Packet Forwarding Locator: 3 parts core exit point intermediate exit point identifier (ID) Forwarding: 1 send packet to core (direct peerings supported) 2 forward along exit points Local routing scope within hierarchy levels ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 10
HAIR: Hierarchical Mapping System Design requirements scale with number of hosts fast response times Hierarchical directories: local: intermediates global: core Resolve mapping 1 get pointer to local directory 2 get actual mappings Edge-based: request sent by end host no action needed from e.g., core exit points ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 11
Dynamics Link/router failure inside core or intermediate: find alternative route between all pairs of exit points updates are localized in scope to core or intermediate Failing or unreachable exit point: e.g., monitor reachability of exit points update all affected locators in the mapping system Change of locator: intra-domain : update local directory inter-domain : update global directory, move locators ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 12
Outline 1 Related Work 2 Architecture 3 Evaluation 4 Conclusion ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 13
Estimating the Benefits Goal: benefits if HAIR was deployed in today s Internet? how much can we scale the DFZ routing table? core isolated from update churn originated by edge? Data sources BGP updates and table dumps classification of ASs according to business type e.g., transit provider, enterprise networks Dhamdhere et al., IMC 2008 ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 14
Estimating the Benefits Results DFZ table size: reduction by more than a half Updates: majority of current updates from edge, see plot EDGE EDGE Scalability since Internet mainly grows at the edge ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 15
Proof-of-Concept Implementation Requirements: support existing applications standard IP forwarding user space bootstrapping Use existing software IPv6 Click Scapy Setup in testbed latency: ping throughput iperf mobility scenarios ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 16
Discussion/Summary Scalability routing AND mapping largely on a local scope HAIR captures growth of Internet at the edge Multihoming, multipath, inbound traffic engineering: can be supported by mapping system Migration path support legacy hosts via NAT-like boxes ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 17
Outline 1 Related Work 2 Architecture 3 Evaluation 4 Conclusion ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 18
Conclusion Key ideas: separation of locator/identifier function of IP address use of hierarchical routing and mapping system edge-based: if possible transfer tasks to edge hosts, keep network simple Current status: architecture specified proof-of-concept implementation demonstrates feasibility Future work: mapping system security model and analysis ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 19
Thank you! ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 20
Conclusion Key ideas: separation of locator/identifier function of IP address use of hierarchical routing and mapping system edge-based: if possible transfer control to edge hosts, keep network simple Current status: architecture specified proof-of-concept implementation demonstrates feasibility Future work: mapping system security model and analysis ReArch 09 Rome, Italy December 1st, 2009 HAIR: Hierarchical Architecture for Internet Routing 21