national chi nan university a brief introduction to lisp ( locator/id separation protocol ) speaker:...
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National Chi Nan University
A Brief Introduction to LISP ( Locator/ID Separation Protocol )
Speaker: Dennis (Shu-Cheng Li)
National Chi Nan University
Outline
• 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。
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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– 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 de-encapsulates 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
• 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 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/RRG-7.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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