Ppt on switching network protocol

5: DataLink Layer5-1 Chapter 5 Link Layer and LANs Computer Networking: A Top Down Approach 4 th edition. Jim Kurose, Keith Ross Addison-Wesley, July 2007.

(can collide with each other) r today: star topology prevails m active switch in center m each “spoke” runs a (separate) Ethernet protocol (nodes do not collide with each other) switch bus: coaxial cable star 5: DataLink Layer5-52 Ethernet Frame Structure Sending adapter encapsulates IP datagram (or other network layer protocol packet) in Ethernet frame Preamble: r 7 bytes with pattern 10101010 followed by/


Chapter 5: The Data Link Layer r Application r Transport r Network r data link layer service m Moving data between nearby network elements Move data between.

m link layer addressing r instantiation and implementation of various link layer technologies m Ethernet m switched LANS m PPP m virtualized networks as a link layer: ATM, MPLS Chapter 5: let’s take a breath r journey down protocol stack complete (except PHY) r solid understanding of networking principles, practice r ….. could stop here …. but lots of interesting topics! m wireless m multimedia/


Copyright © 2013 Rockwell Automation, Inc. All rights reserved. PUBLIC INFORMATION Rev 5058-CO900E Fundamentals of Network Resiliency and Redundant Path.

EIGRP) are resilient by nature 17 Copyright © 2013 Rockwell Automation, Inc. All rights reserved. PUBLIC INFORMATION Network Resiliency Protocols Layer 3 Distribution switches typically provide first hop (default gateway) redundancy –StackWise (3750X), stack management –Hot Standby Router Protocol (HSRP) –Virtual Router Redundancy Protocol (VRRP) –Gateway Load Balancing Protocol (GLBP) Catalyst 3750x Switch Stack HSRP Active HSRP Standby Catalyst 3560 18 Copyright © 2013 Rockwell Automation, Inc. All rights/


Data Link Layer5-1 Chapter 5 Link Layer and LANs All material copyright 1996-2010 J.F Kurose and K.W. Ross, All Rights Reserved Computer Networking: A.

life… using DNS DNS UDP IP Eth Phy DNS  IP datagram containing DNS query forwarded via LAN switch from client to 1 st hop router  IP datagram forwarded from campus network into comcast network, routed (tables created by RIP, OSPF, IS-IS and/or BGP routing protocols) to DNS server  demuxed to DNS server  DNS server replies to client with IP address of www/


ITEC 275 Computer NetworksSwitching, Routing, and WANs Week 5 Robert D’Andrea Winter 2016.

addresses to populate the MAC address table, but has not yet forwarded user frames - Forwarding is a port that is learning MAC addresses and forwarding user frames. Rapid Spanning Tree Protocol Converged switched network Bridge port roles - Root port assigned on a non-root bridge, provides lowest cost path to the root bridge. - Designated assigned on a port attached to a LAN, provides/


Troubleshooting Performance Issues on Switches. Identifying Switch Performance Issues This section covers the Cisco IOS commands to perform the following.

(data plane) consists of two steps: Step 1. Making a routing decision (based on): – Network topology information and configured policies – Information about network destinations, gathered by a routing protocol – Possible restrictions (access lists or policy-based routing (PBR) Step 2. Switching the packet: – Not to be confused with Layer 2 switching – Involves moving a packet from an input buffer to an output buffer – Rewriting the/


Switch Features Most enterprise-capable switches have a number of features that make the switch attractive for large organizations. The following is a.

and then turn around and connect Switch2 back to Switch1 using a different cable and ports on the switches. Having a loop on the network could cause the network to go down and creates instability in the switches. To prevent this, STP was designed. STP is a protocol that looks at all of the ports used to create a loop and then places one of/


Link Layer Computer Networks Lin Gu Computer Networking: A Top Down Approach 6 th edition. Jim Kurose and Keith Ross, Pearson. Part of the.

5.1 introduction, services 5.2 error detection, correction 5.3 multiple access protocols 5.4 LANs  addressing, ARP  Ethernet  switches  VLANS 5.5 link virtualization: MPLS 5.6 data center networking 5.7 a day in the life of a web request Link Layer5-3 /1 introduction, services 5.2 error detection, correction 5.3 multiple access protocols 5.4 LANs  addressing, ARP  Ethernet  switches  VLANS 5.5 link virtualization: MPLS 5.6 data center networking 5.7 a day in the life of a web request Link Layer5-/


5: DataLink Layer 5a-1 Chapter 5 Data Link Layer Computer Networking: A Top Down Approach Featuring the Internet, 3rd edition. Jim Kurose, Keith Ross Addison-Wesley,

-50 Star topology r Bus topology popular through mid 90s r Now star topology prevails r Connection choices: hub or switch (more later) hub or switch 5: DataLink Layer 5a-51 Ethernet Frame Structure Sending adapter encapsulates IP datagram (or other network layer protocol packet) in Ethernet frame Preamble: r 7 bytes with pattern 10101010 followed by one byte with pattern 10101011 r used/


Mobile Computing Lab. Computer Network 2009/Fall 1 Gihwan Cho Computer Networks 2009/Fall Division of Computer Science & Engineering Chonbuk University.

Cho PDUs in TCP/IP Mobile Computing Lab. Computer Network 2009/Fall 15 Gihwan Cho Some Protocols in TCP/IP Suite Mobile Computing Lab. Computer Network 2009/Fall 16 Gihwan Cho Lecture Topic III Wide Area Networks 사자는 사냥감이 토끼냐 말이냐에 따라서 사냥방법을 달리하지 않는다. 단지 최선을 다할 뿐이다. Mobile Computing Lab. Computer Network 2009/Fall 17 Gihwan Cho Chapter 10 : Circuit Switching & Packet Switching  Simple switched network Mobile Computing Lab. Computer Network 2009/Fall 18 Gihwan Cho Nodes  Long distance transmission/


Data Link Layer5-1 Computer Networking: A Top Down Approach 5 th edition. Jim Kurose, Keith Ross Addison-Wesley, April 2009. Computer Networks Dr. Guifeng.

life… using DNS DNS UDP IP Eth Phy DNS  IP datagram containing DNS query forwarded via LAN switch from client to 1 st hop router  IP datagram forwarded from campus network into comcast network, routed (tables created by RIP, OSPF, IS-IS and/or BGP routing protocols) to DNS server  demuxed to DNS server  DNS server replies to client with IP address of www/


Exploration 4 Chapter 1. What is a WAN? A WAN is a data communications network that operates beyond the geographic scope of a LAN. A WAN is a data communications.

rate of international PRI corresponds to an E1 or J1 connection. Common Packet Switching WAN Technologies - X.25 X.25 is a legacy network-layer protocol that provides subscribers with a network address. X.25 is a legacy network-layer protocol that provides subscribers with a network address. Virtual circuits can be established through the network with call request packets to the target address. Virtual circuits can be/


11 CS716 Advanced Computer Networks By Dr. Amir Qayyum.

–Maintains forwarding table for translations Each packet forwarded and travels independently 175 Datagram Switching Managing tables in large, complex networks with dynamically changing topologies is a real challenge for the routing protocol 0 1 3 2 0 1 3 2 0 1 3 2 Switch 3 Host B Switch 2 Host A Switch 1 Host C Host D Host E Host F Host G Host H/


Christian Esteve Rothenberg

Essentially requires aggregated (wildcard) rules Usage examples Alice’s code: Simple learning switch Per Flow switching Network access control/firewall Static “VLANs” Her own new routing protocol: unicast, multicast, multipath Home network manager Packet processor (in controller) IPvAlice VM migration Server Load balancing Mobility manager Power management Network monitoring and visualization Network debugging Network slicing What is possible in the controller? Anything that needs intelligent routing of/


Industrial Networking & Connectivity

cellular Give an existing PC access to remote DAQ hardware via celluar Industrial Networking and Connectivity Seminar Industrial Networking and Connectivity Seminar Advanced Networking Protocol Analyzer Using Managed Switches VLAN’s VPN SNMP Network Security Return Industrial Networking and Connectivity Seminar Some Switch Terminology Auto Negotiation Ability of a switch to set data rate and half vs. full duplex between devices Auto Crossover Ability to determine which wire pairs/


Management of MPLS-based VPNs

of Standard and Technology) GMPLS Simulator (GLASS: Gmpls Lightpath Agile Switching Simulator): http://dns.antd.nist.gov/glass/ Networking Simulator for Generalized Multi-Protocol Label Switching (GMPLS) DiffServ-over-MPLS MPLS Networking WDM Optical Switching General Internet Applications over TCP/UDP, IP Included MPLS OAM functions to monitor, analysis network operational status Network Simulation for DiffServ-over-MPLS  Network Configuration Server Client LSR120 LSR 121 LSR 220 LSR 221/


Introduction CS 3516 – Computer Networks

Internet? 1.2 Network edge end systems, access networks, links 1.3 Network core circuit switching, packet switching, network structure 1.4 Delay, loss and throughput in packet-switched networks 1.5 Protocol layers, service models 1.6 Networks under attack: security 1.7 History A Closer Look at Network Structure Network edge: applications and hosts Access networks, physical media: wired, wireless communication links Network core interconnected routers network of networks The Network Edge End systems (hosts/


Introduction1-1 Chapter 1 Introduction Computer Networking: A Top Down Approach Featuring the Internet, 3 rd edition. Jim Kurose, Keith Ross Addison-Wesley,

1.1 What is the Internet? 1.2 Network edge 1.3 Network core 1.4 Network access and physical media 1.5 Internet structure and ISPs 1.6 Delay & loss in packet-switched networks 1.7 Protocol layers, service models 1.8 History Introduction1-11 A closer look at network structure: network edge: applications and hosts network core: routers network of networks access networks, physical media: communication links Introduction1-12 The/


MSc WLAN, IP/TCP and COMM NETWORK Topics

answer. 7)      What does ‘negotiation’ mean when discussing network protocols? Give an example of it. 8)      Give three examples of protocol parameters that might be negotiated when a connection is set up. 9)      Discuss the advantages and disadvantages of message switching over circuit switching and performance comparison. 10)  Discuss the advantages/disadvantages of packet switching over circuit switching (and performance comparison) 11)  Discuss the characteristics and medium/


Introduction 1-1 Chapter 1 Introduction Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 A note on.

more on security (throughout, Chapter 8) Introduction Chapter 1: roadmap 1.1 what is the Internet? 1.2 network edge end systems, access networks, links 1.3 network core packet switching, circuit switching, network structure 1.4 delay, loss, throughput in networks 1.5 protocol layers, service models 1.6 networks under attack: security 1.7 history 1-69 Introduction Internet history 1961: Kleinrock - queueing theory shows effectiveness of/


Chapter 1 Communication Networks and Services

per integrated circuit every two years RAM: larger tables, larger systems Digital signal processing: transmission, multiplexing, framing, error control, encryption Network processors: hardware for routing, switching, forwarding, and traffic management Microprocessors: higher layer protocols and applications Higher speeds and higher throughputs in network protocols and applications Moore’s Law P4 Pentium III Pentium Pro Pentium II Transistor count 486 DX Intel DX2 80286 8086 8080/


Chapter 4 Network Layer Computer Networking: A Top Down Approach 6th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 A note on the use of these.

to port Y, controller closes cross point at intersection of two buses advanced design: fragmenting datagram into fixed length cells, switch cells through the fabric. A crossbar B C X Y Z Network Layer Output ports datagram buffer queueing switch fabric link layer protocol (send) line termination buffering required when datagrams arrive from fabric faster than the transmission rate scheduling discipline chooses among queued/


Chapter 4 Network Layer Computer Networking: A Top Down Approach 6th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 A note on the use of these.

bus, Cisco 5600: sufficient speed for access and enterprise routers bus Network Layer Switching via interconnection network overcome bus bandwidth limitations banyan networks, crossbar, other interconnection nets initially developed to connect processors in multiprocessor Cisco 12000: switches 60 Gbps through the interconnection network crossbar Network Layer Output ports datagram buffer queueing switch fabric link layer protocol (send) line termination buffering required when datagrams arrive from fabric/


Mobility Management in IP-Based Wireless Networks

a paging message 3. Mobility Management in 3GPP Paket Networks Assumptions mobility management in packet-switched (PS) domain of a 3GPP network (Release 5) RAN is assumed to be UTRAN 3GPP Conceptual Network Architecture (Release 5) 3GPP Network Architecture and Protocol Reference Model (Release 5) Components Public Land Mobile Network (PLMN) a public network administrated by a single network operator for providing land mobile services 3GPP PLMN consists of/


Cisco Networking Academy Program New CCNA Curricula

Objectives Chapter Outlines Routing Protocols and Concepts LAN Switching and Wireless Accessing the WAN CCNA Exploration 1 – Network Fundamentals Course Objectives Explain the importance of data networks and the Internet as a platform to support business communications and everyday tasks Explain how communication occurs in data networks and the Internet Describe the devices and services that support communication across an Internetwork Use network protocol models to explain/


Introduction 1-1 Chapter 1 Introduction Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 A note on.

sender or impersonating another computing system Introduction Chapter 1: roadmap 1.1 what is the Internet? 1.2 network edge end systems, access networks, links 1.3 network core packet switching, circuit switching, network structure 1.4 delay, loss, throughput in networks 1.5 protocol layers, service models 1.6 networks under attack: security 1.7 history 1-71 Introduction Internet history 1961: Kleinrock - queueing theory shows effectiveness of/


Mobile Communication and Mobile Computing

per BSC Physical channels defined by number and position of time slots GSM: protocols, incoming call (4) BSS (3) VLR HLR (8) (7) (6) (11) (10) (4) (2) (8) (8) PSTN/ ISDN (5) (1) (9) (9) MSC GMSC BSS BSS (12) (12) (8) BSS (1) Call from fixed network was switched via GMSC (2) GMSC finds out HLR from phone number and transmits/


COMPUTER SYSTEMS An Integrated Approach to Architecture and Operating Systems Chapter 13 Fundamentals of Networking and Network Protocols ©Copyright 2008.

input or the output buffer being full and is indicative of traffic congestion on specific routes of the network. Service ModelThis is the contract between the network layer and the upper layers of the protocol stack. Both the datagram and virtual circuit models used in packet- switched networks provide best effort delivery of packets. Virtual Circuit (VC) This model sets up a virtual circuit between/


CS 640 Introduction to Computer Networks Fall 1999 Professor Landweber Copyright 1999, Lawrence H. Landweber Copyright 1996, Larry Peterson (slides marked.

support congestion handling or quality of service mechanisms Examples –routers - IP –switches - ATM or local area networks (e.g., Ethernet-802.3, token ring) –bridges, hubs - local area networks Network Types - Direct Connectivity point-to-point mulitpoint /broadcast Ethernet Token Ring Also satellite/radio Network Types - Indirect Connectivity switched networks internetworks backbone link host switching element Protocols A protocol is a set of conventions that specifies the rules or parameters/


Data Link Layer CS 3516 – Computer Networks

same collision domain (can collide with each other) Today: star topology prevails Active switch in center (contrast with hub) Each “spoke” runs a (separate) Ethernet protocol (nodes do not collide with each other) switch bus: coaxial cable star Ethernet Frame Structure Sending adapter encapsulates IP datagram (or other network layer protocol packet) in Ethernet frame Preamble: 7 bytes with pattern 10101010 followed by one byte/


Link Layer 5.1 Introduction and services

same collision domain (can collide with each other) today: star topology prevails active switch in center each “spoke” runs a (separate) Ethernet protocol (nodes do not collide with each other) switch bus: coaxial cable star 5: DataLink Layer Ethernet Frame Structure Sending adapter encapsulates IP datagram (or other network layer protocol packet) in Ethernet frame Preamble: 7 bytes with pattern 10101010 followed by one byte/


Chapter 5 Link Layer and LANs

frame format different speeds: 2 Mbps, 10 Mbps, 100 Mbps, 1Gbps, 10G bps different physical layer media: fiber, cable Switched Ethernet: use frame bursting to increase utilization. Still CSMA/CD compatible MAC protocol and frame format application transport network link physical copper (twister pair) physical layer 100BASE-TX fiber physical layer 100BASE-T2 100BASE-FX 100BASE-T4 100BASE-SX 100BASE-BX 5: DataLink/


Introduction1-1 Chapter 1 Computer Networks and the Internet Computer Networking: A Top Down Approach Featuring the Internet, 2 nd edition. Jim Kurose,

ISP local ISP local ISP Introduction1-53 Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge 1.3 Network core 1.4 Network access and physical media 1.5 Internet structure and ISPs 1.6 Delay & loss in packet-switched networks 1.7 Protocol layers, service models 1.8 History Introduction1-54 How do loss and delay occur? packets queue in router/


CSE 5808 Quality of Service in Digital Communication Networks

User Level QoS Facilities regarding to the classification and prioritisation of traffic flow started in X.25 and frame relay networks. X.25 is a protocol suite for earlier, low speed packet switch networks. X.25 packets have header fields for the negotiation of network resource. It has facility to provide connection oriented virtual circuit and special types of packets for flow control. Frame relay/


Train IT – Computer Networks University of Debrecen

frame starts immediately on the outgoing port. Fragment free switching: After arriving a minimum frame length (64 bytes), the transmission of frame starts on the outgoing port. (Collided frames will not be transmitted.) Train IT - Networks 78 Debrecen, 2012. IV. – Network Layer Train IT - Networks 79 Debrecen, 2012. The IP Network Protocol IP (Internet Protocol) RFC 791 The network layer protocol of TCP/IP reference model. Widely used, it/


Http://munz-udo.de IP Multicasting.

RP hashing algorithm. Comparison and Compatibility of PIM Version 1 and Version 2 PIM version 2 is a standards-based multicast protocol in the Internet Engineering Task Force (IETF). Cisco highly recommends using PIM version 2 in the entire multilayer switched network. Ciscos PIM version 2 implementation allows interoperability and transition between version 1 and version 2, although there are a few caveats/


Www.planet.com.tw Ethernet Switch Copyright © PLANET Technology Corporation. All rights reserved.

Per-Port routing and VLAN routing mode Multicast Routing Protocol: IGMP, DVMRP, PIM-DM/SM VRRP protocol for redundant routing deploy Policy-Based DiffServ QoS, classified by TCP/UDP, IP Address, VLAN and DSCP/TOS SNMP v1, v2c, and v3 switch management SSH and SSL security management Access Control List and Port-Security for Network security control WGS3-2820 DepartmentManagedIP L3 www.planet.com/


Part 2 Logical Network Design

information should be separate from the front-end Web server that users see. Securing Remote-Access and Virtual Private Networks (VPN) Physical security Firewalls Authentication, authorization, and auditing Encryption One-time passwords Security protocols CHAP RADIUS IPSec Securing Network Services Treat each network device (routers, switches, and so on) as a high-value host and harden it against possible intrusions Require login IDs and passwords/


Chapter 5 Link Layer Computer Networking: A Top Down Approach 6th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 A note on the use of these.

5.1 introduction, services 5.2 error detection, correction 5.3 multiple access protocols 5.4 LANs addressing, ARP Ethernet switches VLANS 5.5 link virtualization: MPLS 5.6 data center networking 5.7 a day in the life of a web request Link Layer Link layer/ 5.1 introduction, services 5.2 error detection, correction 5.3 multiple access protocols 5.4 LANs addressing, ARP Ethernet switches VLANS 5.5 link virtualization: MPLS 5.6 data center networking 5.7 a day in the life of a web request Link Layer Error /


FP6 IST “Broadband for all” Network of Excellence Contract n

allocation and provision of guaranteed services Optical packet switched network solutions for metro Metro-access interface – technologies and protocols enabling transparency Management, control and interoperability of advanced metro nets Cost efficient solutions, components and technologies Strategies towards optical metro Metro network evolution, migration studies and techno-economics VD-M: Metro Networks Technologies, Architectures and Protocols Running Joint Activities in VD-M: Traffic engineering/


Copyright © PLANET Technology Corporation. All rights reserved.

Per-Port routing and VLAN routing mode Multicast Routing Protocol: IGMP, DVMRP, PIM-DM/SM VRRP protocol for redundant routing deploy Policy-Based DiffServ QoS, classified by TCP/UDP, IP Address, VLAN and DSCP/TOS SNMP v1, v2c, and v3 switch management SSH and SSL security management Access Control List and Port-Security for Network security control Department Managed IP L3 WGS3-2820 17/


Computer Networks Text Book By Larry L Peterson & Bruce S. Davie.

. Presentation layer is concerned with the format of data exchanged between peers Application layer Protocols include File Transfer Protocol (FTP), TELNET, SMTP, etc Internet Architecture The Internet architecture, which is also sometimes called the TCP/IP architecture. The Internet architecture evolved out of experiences with an earlier packet-switched network called the ARPANET. Both the Internet and the ARPANET were funded by the Advanced/


CSCE 416: Introduction to Computer Networks

.W. Ross, All Rights Reserved Introduction Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge end systems, access networks, links 1.3 Network core circuit switching, packet switching, network structure 1.4 Delay, loss and throughput in packet-switched networks 1.5 Protocol layers, service models 1.6 Networks under attack: security 1.7 History Introduction What’s the Internet: “nuts and bolts” view PC server/


Advanced Computer Networks

and management, S.T. Karris, Orchard, 2004 Advanced computer networks, 2011 Advanced computer networks, 2011 Computer networks and Internet What is the Internet? The network edge The network core Delay, loss and throughput in packet-switched networks Protocol layers and their service models History of computer networking and Internet ATM networks Why ATM? ATM layers ATM adaptation layer ATM signaling The Network layer Routing algorithms Routing in the Internet Internetworking IP/


Chapter 6: Securing the Campus Infrastructure

specific privilege level. An example is limiting network operation users to only show commands when accessing switches and routers in the enterprise network for normal operations. EXEC: Refers to the attributes associated with a user EXEC terminal session. Network: Applies to the types of network connections. An example of using network authorization is authorization granting remote users access to network protocols such as PPP, SLIP, or ARAP during/


Module 9: Installing and Configuring Network Load Balancing

cluster hosts. You can configure a virtual LAN by manually programming the switch or by using the Internet Group Management Protocol (IGMP) or the Generic Attribute Registration Protocol Multicast Registration Protocol. Note: The current version of Windows Network Load Balancing does not provide automatic support for IGMP or Generic Attribute Registration Protocol Multicast Registration Protocol. Unicast Mode The unicast operation uses a single MAC address for all/


1 Multiprotocol Label Switching The future of IP Backbone Technology Ravikumar Pragada & Girish Srinivasan.

future of IP Backbone Technology Ravikumar Pragada & Girish Srinivasan 2 Overview Need for MPLS MPLS Basics Benefits Label Switched Path Label Distribution Protocol Hierarchy in MPLS Explicit Routing Loop Detection Traffic Engineering Constraint Based Routing Tag Switching IP Switching Conventional IP Networks & Routing Client networks are connected to backbone via edge routers –LAN, PSTN, ADSL Data packets are routed based on IP address and other information/


Protocoles réseaux Sommaire (prévision): Couche liaison de données

ISP local ISP local ISP Introduction Chapter 1: roadmap 1.1 What is the Internet? 1.2 Network edge end systems, access networks, links 1.3 Network core circuit switching, packet switching, network structure 1.4 Delay, loss and throughput in packet-switched networks 1.5 Protocol layers, service models 1.6 Networks under attack: security 1.7 History Introduction How do loss and delay occur? packets queue in router/


Introduction1-1 COMP 361: “Network Part I” Qian Zhang Fall 2006 HKUST.

1.1 What is the Internet? 1.2 Network edge 1.3 Network core 1.4 Network access and physical media 1.5 Internet structure and ISPs 1.6 Delay & loss in packet-switched networks 1.7 Protocol layers, service models 1.8 History Introduction1-21 A closer look at Network Structure:  Network edge: applications and hosts  Network core:  Routers  Network of networks  Access networks, physical media: communication links Introduction1-22 The/


Configuring Juniper Networks Routers

-independent routing option configuration > snmp Simple Network Management Protocol > system System parameters jeff@host# edit Configuration Statement Hierarchy Example Move around the Hierarchy [edit] jeff@host# edit protocols ? Possible completions: > bgp BGP options > dvmrp DVMRP options > igmp IGMP options > isis IS-IS configuration > mpls Multiprotocol label switching options > ospf OSPF configuration ... [edit protocols] jeff@host# edit protocols ospf ? <[Enter]> Execute this command > area Configure/


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