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LISP and BGP. IDR WG, IETF Dublin, July, 2008 Vince Fuller (for the LISP crew). Agenda. Motivation for LISP (and ALT) How LISP+ALT uses BGP A few considerations. LISP Internet Drafts. draft-farinacci-lisp-08.txt draft-fuller-lisp-alt-02.txt draft-lewis-lisp-interworking-01.txt
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LISP and BGP IDR WG, IETF Dublin, July, 2008 Vince Fuller (for the LISP crew)
Agenda • Motivation for LISP (and ALT) • How LISP+ALT uses BGP • A few considerations IETF Dublin, July, 2008
LISP Internet Drafts draft-farinacci-lisp-08.txt draft-fuller-lisp-alt-02.txt draft-lewis-lisp-interworking-01.txt draft-farinacci-lisp-multicast-00.txt draft-meyer-lisp-eid-block-01.txt draft-mathy-lisp-dht-00.txt draft-iannone-openlisp-implementation-01.txt draft-brim-lisp-analysis-00.txt draft-meyer-lisp-cons-04.txt draft-lear-lisp-nerd-04.txt draft-curran-lisp-emacs-00.txt IETF Dublin, July, 2008
Separate EID/RLOC topologies “Addressing can follow topology or topology can follow addressing – choose one” –Y.R. • ID/LOC separation avoids this dilemma • EIDs uses organization/geo hierarchy • RLOCs follow network topology • Reduce global routing state through RLOC aggregation • EID prefixes are not generally visible in global routing system IETF Dublin, July, 2008
ISP allocates 1 locator address per physical attachment point (follows network topology) RIR allocates EID-prefixes (follows org/geo hierarchy) R1 R2 EID vs RLOC assignment Provider A 10.0.0.0/8 Provider B 11.0.0.0/8 11.0.0.1 10.0.0.1 Site Legend: EIDs -> Green Locators -> Red PI EID-prefix 240.1.0.0/16 IETF Dublin, July, 2008
LISP+ALT: What, How and Why • Hybrid push/pull approach • ALT pushes aggregates - find ETRs for EID • ITR uses LISP to find RLOCs for specific EID • Hierarchical EID prefix assignment • Aggregation of EID prefixes • Tunnel-based overlay network • BGP used to advertise EIDs on overlay • Why invent something new? (or use DNS?) • Option for data-triggered Map-Replies IETF Dublin, July, 2008
11.0.0.1 -> 240.1.1.1 11.0.0.1 -> 240.1.1.1 240.0.0.1 -> 240.1.1.1 240.0.0.1 -> 240.1.1.1 <- 240.1.1.0/24 < - 240.1.0.0/16 <- 240.1.2.0/24 240.0.0.1 -> 240.1.1.1 240.0.0.1 -> 240.1.1.1 ITR ITR ETR ETR ETR 11.0.0.1 -> 1.1.1.1 ? ? ? ? 1.1.1.1 -> 11.0.0.1 240.0.0.1 -> 240.1.1.1 ALT-rtr ALT-rtr ALT-rtr ALT-rtr ALT-rtr ALT-rtr LISP+ALT in action EID-prefix 240.0.0.0/24 EID-prefix 240.1.1.0/24 1.1.1.1 11.0.0.1 2.2.2.2 12.0.0.1 Legend: EIDs -> Green Locators -> Red GRE Tunnel Low Opex Physical link Data Packet Map-Request Map-Reply 3.3.3.3 LAT IETF Dublin, July, 2008
Securing the mapping system • ALT can use existing/proposed BGP security mechanisms (SBGP, etc.) • DOS-mitigation using well-known control plane rate-limiting techniques • Nonce in LISP protocol exchange • More needed? IETF Dublin, July, 2008
Non-BGP traffic engineering • ALT separates ETR discovery from the ITR-ETR mapping exchange • very coarse prefixes globally-advertised • more-specific info exchanged where needed • Regional ETRs could return more- specific mappings for simple TE • Alternative to current practice of advertising more-specific prefixes IETF Dublin, July, 2008
Simple BGP configs • No BGP changes required for LISP+ALT • None made for pilot deployment • Though separate AFI/SAFI might be a good idea for debugging/management • No need for route-reflectors, etc. • May use iBGP in some cases IETF Dublin, July, 2008
Questions/Comments? Contact us: lisp-interest@lists.civil-tongue.net Information: http://www.lisp4.net OpenLISP: http://inl.info.ucl.ac.be Thanks! IETF Dublin, July, 2008 Slide 11