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LISP Interworking. LISP BOF, IETF 72 Dublin, July, 2008 Darrel Lewis (for the LISP crew). Agenda. Overview of LISP Interworking Proxy Tunnel Routers LISP Network Address Translation Open Issues. LISP Internet Drafts. draft-farinacci-lisp-08.txt draft-fuller-lisp-alt-02.txt
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LISP Interworking LISP BOF, IETF 72 Dublin, July, 2008 Darrel Lewis (for the LISP crew)
Agenda • Overview of LISP Interworking • Proxy Tunnel Routers • LISP Network Address Translation • Open Issues
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
LISP Interworking Models • Non-LISP site to Non-LISP site • Today’s Internet • LISP site to LISP site • Not an Interworking problem • LISP site to Non-LISP site • Non-LISP site to LISP site • These last two are related
What About Routable EIDs • EIDs published in both the existing BGP DFZ and the LISP mapping database • Essentially there are no sites that are ‘LISP-NR’ • EIDs can only be withdrawn from a table after transition is ‘completed’ • This mechanism will provide a low cost way for initial LISP sites to transition… • But this isn’t really a viable option long term
Interworking Mechanisms • Proxy Tunnel Routers • A network element that provides ITR processing to • LISP NAT • A limited form of NAT allowing for a site to control its Interworking
NR-prefix 1.1.0.0/16 1.3.3.3 -> 65.3.3.3 66.3.3.3 ->65.3.3.3 R-prefix 65.1.0.0/16 66.1.1.1 Encapsulate NR-prefix 1.2.0.0/16 66.2.2.2 Forward R-prefix 65.2.0.0/16 66.1.1.1 -> 66.2.2.2 Forward NR-prefix 1.3.0.0/16 R-prefix 65.3.0.0/16 1.1.1.1 -> 1.2.2.2 65.3.3.3 -> 66.3.3.3 Forward 65.3.3.3 -> 1.3.3.3 Interworking Example 65.0.0.0/12 66.0.0.0/12 Legend: LISP Sites -> Green (and EIDs) non-LISP Sites -> Red (and RLOCs) xTR Local/Uncoordinated Solution
Proxy Tunnel Routers (PTRs) • Originate EID Prefixes • Advertise highly aggregated EID-prefix space • Can use proxy aggregation • IPv6 EID space is a contiguous • 2610:00d0::/32 • Performs LISP encapsulation
Properties of PTRs • Traffic is Asymmetrical • Law of Large Numbers for PTR cache performance • Placing near the source of traffic allows for traffic to be routed on RLOCs as soon as possible, minimizing potential stretch
Deploying PTRs • PTRs attract traffic • SPs who deploy PTRs will attract traffic • Post encap traffic can best utilize closest exit • SPs who do not deploy PTRs will send traffic to those who do • Motivate them to do so to enable more of their traffic to utilize closest exit, non transit (cheaper) paths
PTR PTR PTR NR-prefix 1.1.0.0/16 R-prefix 65.1.0.0/16 66.1.1.1 65.0.0.0/12 Encapsulate NR-prefix 1.2.0.0/16 66.2.2.2 65.9.1.1 Forward R-prefix 65.2.0.0/16 65.9.1.1 -> 66.1.1.1 NR-prefix 1.3.0.0/16 R-prefix 65.3.0.0/16 65.1.1.1 -> 1.1.1.1 66.0.0.0/12 65.1.1.1 -> 1.1.1.1 1.1.1.1 -> 65.1.1.1 Interworking Experiment 1.0.0.0/8 Legend: LISP Sites -> Green (and EIDs) non-LISP Sites -> Red (and RLOCs) xTR Infrastructure Solution
LISP-NAT • LISP-NAT: • Allows a site to control how it implements LISP Interworking • LISP-NAT has all the classic issues with NAT • Not proposed as a solution for IPv6
Open Issues • Motivation to Deploy PTRs • What benefits to customers • Can it be monetized • Who is going to deploy them • Scaling PTRs • Anycasting the PTR next hop • Selective route announcements of the EID space • How difficult to implement in hardware • Evaluate LISP-NAT vs LISP PTR performance • Other?