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A Brief Introduction to LISP
( Locator/ID Separation Protocol )
Speaker: Dennis (Shu-Cheng Li)
Outline
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Introduction
Definition of terms
Overview
Mapping
Header Format
Use Cases
Conclusion
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Introduction
• 現今的網際網路(Internet)架構是在1970年代所發
展出來的，隨時代的演變，網際網路的需求與當
時的設計有著很顯著的差異。
• 目前的IP位址架構設計是將位址同時當作網路節
點的身分辨識(Identifier)與所屬的網路位址
(Locator)。
• 這樣的設計方式主要的問題在於無法有效的解決
網路節點的移動性(Mobility)、多重歸屬
(Multihoming)、與路由表的擴充性(Scalable
Routing)等議題。 3
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Introduction Cont.
• 為了解決上述議題，許多研究單提出ID與Locator
分離的概念
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AKARI Project
ITU-T Study Group 13
Locator/ID Separation Protocol (LISP)
Host Identity Protocol (HIP)
SHIM6
• 其中LISP技術的特色是考量現有的網路架構下去設
計的，並且已經實作在Cisco Router上
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Definition of terms
• Ingress Tunnel Router(ITR)
– An ITR is a LISP site edge device that receives
packets from site facing interface and
encapsulates them to remote LISP sites.
• Egress Tunnel Router(ETR)
– An ITR is a LISP site edge device that receives
packets from core facing interface and deencapsulates LISP packets and delivers them to
local EIDs at the site.
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Definition of terms Cont.
• Map Server(MS)
– A MS is a device that ETRs register to with their
EID prefixes. The MS advertises aggregates for the
registered EID prefixes in to the LISP mapping
system.
• Map Resolver(MR)
– A MR is a device that ITRs send LISP map request
queries when resolving EID to RLOC mappings.
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LISP Overview
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LISP Overview Cont.
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LISP Forwarding
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Mapping Lookup
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Mapping Mechanism
映射系統
LISP-NERD
LISP-ALT
LISP-DHT
LISP-FIRMS
映射資訊的存取模式
Push
Pull
Pull
Hybrid
Overlay Network 架構
Flat
Hierarchy
Hierarchy
Hierarchy
所需儲存的映射資訊量
多
少
少
中
查詢延遲
低
中
中
低
更新延遲
高
低
低
高
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LISP-ALT
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LISP Header Format
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LISP Header Format Cont.
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LISP Use Cases
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1. Efficient Multi-Homing
2. IPv6 Transition Support
3. Data Center/VM Mobility
4. Efficient Virtualization/Multi-Tenancy
5. LISP Mobile-Node
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IPv6 Transition Support
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LISP Mobile-Node
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LISP Summary
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Conclusion
• It does not require extra hardware and hence,
the cost of implementation will be very less.
Also, since no new hardware is required, the
transition can be very smooth.
• There is more flexibility in the network.
• The number of addresses that needs to be
advertised is low too.
• The overhead will increase with new headers
getting appended to the messages that will
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impact packet processing.
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Reference
• [1]Alantalkstech, Locator ID Seperation Protocol (LISP)
transition to IPv6,
http://www.youtube.com/watch?v=8AuLmTC5YJs
• [2]IETF Vancouver, Locator/ID Separation Protocol (LISP)
Tutorial, http://www.ietf.org/proceedings/70/slides/RRG7.pdf, December 2007
• [3]Cisco, Locator/ID Separation Protocol Overview,
http://lisp.cisco.com/LISP_Overview.pdf, August 2011
• [4] VARUN JAIN, A STUDY OF LOCATOR ID SEPARATION
PROTOCOL, Unpublished doctoral dissertation, University of
Missouri--Kansas City, 2010
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