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Locator/ID Separation Protocol (LISP) Architecture & Protocols. LISP Team : Vince Fuller, Darrel Lewis, Eliot Lear, Scott Brim, Dave Oran, Elizabeth McGee, Dino Farinacci, and David Meyer Workshop III: Beyond Internet MRA: Networks of Networks Institute for Pure and Applied Mathematics
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Locator/ID Separation Protocol (LISP)Architecture & Protocols LISP Team: Vince Fuller, Darrel Lewis, Eliot Lear, Scott Brim, Dave Oran, Elizabeth McGee, Dino Farinacci, and David Meyer Workshop III: Beyond Internet MRA: Networks of Networks Institute for Pure and Applied Mathematics Nov 3-7, 2008
Agenda • Problem Statement • Locator/ID Separation (and why…) • What is LISP? • LISP Control Plane - LISP+ALT • How LISP sites talk to legacy sites • Other Uses of LISP • Prototype and Pilot Network IPAM MRAWS3
Lower OpEx for Sites and Providers Improve site multi-homing Improve site & provider traffic engineering (3) Reduce size of core routing tables (4) IPv4 Address Conservation? End Site Benefit Easier Transition to IPv6 Change provider without address change Active-Active BGP-free Multihoming Data Center Load Spreading BGP R1 R2 Problem Statement Provider A 10.0.0.0/8 Provider B 11.0.0.0/8 Site with PI Addresses IPAM MRAWS3
Scaling Internet Routing State IPAM MRAWS3
Why Separate Location from ID? • Level of Indirection allows us to: • Keep either ID or Location fixed while changing the other • Basically: Routing Locators need to aggregate topologically, while IDs are usually assigned along administrative boundaries hard to do with one number space • Create separate namespaces which can have different allocation properties • By keeping IDs fixed • Assign fixed addresses that never change to hosts and routers at a site • You can change Locators • Now the sites can change providers • Now the hosts can move IPAM MRAWS3
ID & Location IPv6: 2001:0102:0304:0506:1111:2222:3333:4444 Locator ID IPv4: 209.131.36.158 .10.0.0.1 ID & Location Locator ID Separating (or adding) an Address Changing the semantics of the IP address If PI, get new locator If PA, get new ID IPAM MRAWS3
S R2 R1 Multi-Level Addressing Provider A 10.0.0.0/8 Provider B 11.0.0.0/8 RLOCs used in the core EIDs are inside of sites IPAM MRAWS3
Host Stack: supplies IDs Host Stack: supplies IDs Router: rewrites RLOCs from existing address Router: supplies RLOCs by adding new header Map-n-Encap vs Address-Rewrite Map-n-Encap Address-Rewrite GSE LISP IPAM MRAWS3
So What is LISP? IPAM MRAWS3
What is LISP? • Locator/ID Separation Protocol • Network-based solution • No changes to hosts whatsoever • No new addressing changes to site devices • Very few configuration file changes • Imperative to be incrementally deployable • Address family agnostic IPAM MRAWS3
New Network Elements Ingress Tunnel Router (ITR) Finds EID to RLOC mapping This is the map part of map-and-encap Encapsulates to Locators at source site This is the encap part of map-and-encap Egress Tunnel Router (ETR) Authoritative for its EID to RLOC mapping Decapsulates at destination site IPAM MRAWS3
S D 11.0.0.1 -> 12.0.0.2 11.0.0.1 -> 12.0.0.2 EID-prefix: 2.0.0.0/8 Locator-set: 12.0.0.2, priority: 1, weight: 50 (D1) 13.0.0.2, priority: 1, weight: 50 (D2) Mapping Entry 1.0.0.1 -> 2.0.0.2 1.0.0.1 -> 2.0.0.2 1.0.0.1 -> 2.0.0.2 1.0.0.1 -> 2.0.0.2 S1 S2 D1 D2 Policy controlled by destination site Packet Forwarding PI EID-prefix 1.0.0.0/8 PI EID-prefix 2.0.0.0/8 ETR ITR Provider A 10.0.0.0/8 Provider X 12.0.0.0/8 12.0.0.2 10.0.0.1 ITR ETR 11.0.0.1 13.0.0.2 Provider B 11.0.0.0/8 Provider Y 13.0.0.0/8 DNS entry: D.abc.com A2.0.0.2 Legend: EIDs -> Green Locators -> Red IPAM MRAWS3
Mapping Database Designs • You need a “map” before you can “encap” • We have designed several mapping database protocols • CONS, NERD, EMACS, ALT • Tradeoff push versus pull benefit/cost • Needs to be scalable to 1010 entries • ALT has the most promise • We are deploying ALT IPAM MRAWS3
What is LISP+ALT? • EID namespace is used at the site • RLOC namespace is used in the Internet core • Mappings need to be authoritative and reside at site ETRs • Advertise EID-prefixes in BGP on an alternate topology of GRE tunnels • ITRs get mappings by routing Map-Requests on ALT topology • ETRs respond with Map-Replies IPAM MRAWS3
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 How LISP+ALT Works EID-prefix 240.0.0.0/24 EID-prefix 240.1.1.0/24 1.1.1.1 11.0.0.1 EID-prefix 240.1.2.0/24 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 ALT EID-prefix 240.2.1.0/24 IPAM MRAWS3
Interworking Model • We’ve built and deployed the interworking mechanisms described in draft-lewis-lisp-interworking-01.txt • LISP Translation • “LISP NAT” • http://www.translate.lisp4.net • Proxy Tunnel Router (PTR) • Advertises coarsely aggregated EID-prefix(es) into the DFZ • Attracts traffic for those prefixes • Behaves like an ITR for that traffic • tr0.partan.com is a v4 PTR • titanium-dmm-alt-only.lisp.uoregon.edu is a v6 PTR • http://www.lisp6.net uses the v6 PTR • http://www.lisp4.net uses the v4 PTR IPAM MRAWS3
Other Uses for LISP • SLBs in Data Centers • ETRs directly connected to servers • ITRs at Data Center edge • A/V Mobile Truck Roll • Avoid renumber at each event • BGP-free Core • Intra-AS avoiding storing external routes • RLOCs are PE routers • Building topological hierarchy with flat addressing • MAC addressing in L2 networks • MAC address mobility for “extended subnets” • In an environment of shortage address supply IPAM MRAWS3
Prototype and Pilot • Prototype has been running for a 1.5 years • NX-OS on Titaniums • IOS is under-way • Considering XR and/or CRS blade implementation • Alpha has been running for 1 year • Map-Request/Reply, ALT, & Interworking • External pilot is underway • Dual-stack ALT • Underlying IPv4 and IPv6 transport • Geographical (registry-based) EID addressing • Interworking IPv4 with translation and PTRs • Interworking IPv6 with PTRs • Low-OpEx xTRs underway IPAM MRAWS3
Data Packet EIDs RLOCs Payload OH IH Host Data CE CE CE LISP in one Slide “Separating ID and Location from an IP address through a level of indirection” LISP-ALT Control Plane LISP Site LISP Site Advertises EID-prefixes to find mappings GRE Tunnels GRE Tunnels LISP Routers LISP Routers EIDs EIDs RLOCs RLOCs Physical Links Physical Links Today’s Internet - Data Plane Configure EID ->RLOCs database mappings for local site EIDs assigned by Internet Registries Stores EID ->RLOCs cache mappings for remote sites RLOCs assigned by Service Providers Advertises RLOCsto maintain aggregation and provide reachability to sites • Costs: • Mapping system required • New Software in CE routers • New LISP-ALT infrastructure • Benefits: • Improved low-opex multihoming • Site based policy and reachability • No changes to core routers • No changes to site routers • No DNS changes • No site addressing changes • Works with PI or PA prefixes • Supports 44-over-6 and 66-over-4 • Sites authoritative for their mappings • Interworks with non-LISP sites using • translation or PTRs RLOCs Legend: EIDs (End Site IDs) in green RLOCs (Routing Locators) in red CE: Customer Premise Edge Router ALT: Alternative LISP Topology OH: Outer header, CE to CE IH: Inner header, host to host RLOCs Non-LISP Site Tue Nov 4 18:33:30 PST 2008
LISP Internet Drafts draft-farinacci-lisp-09.txt draft-fuller-lisp-alt-03.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 IPAM MRAWS3
References • Public mailing list: lisp-interest@lists.civil-tongue.net • Go to a LISP site now: http://www.lisp4.net http://www.lisp6.net IPAM MRAWS3