物联网与互联网的关系800字作文英文回答：The relationship between the Internet of Things (IoT) and the Internet is quite close. The IoT is essentially an extension of the Internet, where everyday objects and devices are connected and can communicate with each other. In other words, the IoT is a network of physical objects embedded with sensors, software, and other technologies to collect and exchange data.The Internet, on the other hand, is a global network of computers that are interconnected and communicate with each other using standard protocols. It provides the infrastructure and framework for the IoT to function. Without the Internet, the IoT would not be able to exist.The IoT relies on the Internet to transmit data between devices, analyze the collected data, and enable remote control and monitoring. The Internet provides the necessaryconnectivity and bandwidth for the vast amount of data generated by the IoT devices to be transmitted and processed.Furthermore, the IoT benefits from the existing infrastructure and services of the Internet. Cloud computing, for example, plays a crucial role in the IoT by providing storage and processing capabilities for the massive amounts of data generated by IoT devices. The Internet also provides security protocols and standards to protect the data transmitted and ensure the privacy of users.In summary, the IoT and the Internet are closely intertwined. The Internet provides the foundation and connectivity for the IoT to function, while the IoT extends the capabilities of the Internet by connecting physical objects and enabling them to communicate and interact.中文回答：物联网与互联网的关系非常密切。
DHCP安全问题及其防范措施摘要本文主要介绍计算机网络当中一个比较常见的安全问题—DHCP的安全问题。
DHCP称作动态主机分配协议（Dynamic Host Configuration Protocol, DHCP）是一个局域网的网络协议，使用UDP协议工作，主要有两个用途：给内部网络或网络服务供应商自动分配IP地址给用户给内部网络管理员作为对所有计算机作中央管理的手段。
DHCP用一台或一组DHCP服务器来管理网络参数的分配，这种方案具有容错性。
即使在一个仅拥有少量机器的网络中，DHCP仍然是有用的，因为一台机器可以几乎不造成任何影响地被增加到本地网络中。
甚至对于那些很少改变地址的服务器来说，DHCP仍然被建议用来设置它们的地址。
如果服务器需要被重新分配地址（RFC2071）的时候，就可以在尽可能少的地方去做这些改动。
对于一些设备，如路由器和防火墙，则不应使用DHCP。
把TFTP或SSH服务器放在同一台运行DHCP的机器上也是有用的，目的是为了集中管理。
DHCP也可用于直接为服务器和桌面计算机分配地址，并且通过一个PPP代理，也可为拨号及宽带主机，以及住宅NAT网关和路由器分配地址。
DHCP 一般不适用于使用在无边际路由器和DNS服务器上。
DHCP安全问题在网络安全方面是一个不可忽略的问题，这种问题内部网络及网络服务提供商在分配IP地址造成的IP冲突、伪造DHCP服务器等攻击。
本文介绍了如何防范和解决此类问题的方法和步骤。
关键字：计算机、DHCP、安全问题、攻击DHCP safety and safeguardsABSTRACTThis paper mainly introduces the computer network of a common security problems and DHCP safety problems.DHCP dynamic distribution agreement called the mainframe （Dynamic host configuration protocol and DHCP ）is a LAN network protocols, the use of UDP agreement, there are two major purpose ：to the internal network or network service provider the IP address assigned to the user to the internal network administrator in all computer on the central administration.DHCP with one or a set of DHCP server to manage the distribution network parameters, the scheme has a fault tolerance. Even in a small amount of the machine has a network, and DHCP is still useful, for a machine can hardly have any influence, have been added to the local network. Even for those who rarely change the address of the server and DHCP still being proposed to set the address. If the server needs to be reassigned address （rfc2071 ）, it can be as few as possible to do these changes. For some equipment, such as the router and should not be used DHCP. The TFTP server or SSH in with a DHCP machine is also useful in order to administer.DHCP may also directly to the server and desktop computers, and the assignment of addresses by a PPP agent or a dialing, and broadband host, and the house assignment of addresses NAT gateway and routers generally do not apply. DHCP use in the DNS server marginal routers.DHCP security issues in the network security is not to neglect the issue of the internal network and the network service provider in the allocation of IP address of the conflict and DHCP server IP, forgery attack. This article explains how to prevent and resolve the problem of methods and procedures.Keyword: Computer、DHCP、Safety、Attack目录摘要 (I)ABSTRACT (II)第一章绪论 (1)1.1概述 (1)第二章应用技术 (2)2.1DHCP应用技术 (2)2.2技术优点 (2)2.3应用场合 (2)2.3.1 DHCP服务欺骗攻击 (3)2.3.2 ARP“中间人”攻击 (3)2.3.3 IP/MAC欺骗攻击 (4)2.3.4 DHCP报文泛洪攻击 (4)2.4应用限制 (5)第三章特性介绍 (5)3.1相关术语 (5)3.2相关协议 (6)3.3设备处理流程 (6)3.3.1 DHCP Snooping 表项的建立与老化 (6)3.3.2 DHCP Snooping 信任端口功能 (7)3.3.3 ARP入侵检测功能 (8)3.3.4 IP 过滤功能 (9)3.3.5 DHCP 报文限速功能 (9)3.4DHCP S NOOPING与DHCP R ELAY安全机制比较 (10)第四章典型组网案例 (11)结束语 (12)参考文献 ................................. 错误!未定义书签。
Industry-Leading Performance and Control at the Network CoreEnterasys Networks’ award-winning X-Pedition family represents a new generation of switch routing solutions engineered to support today’s rapidly expanding enterprises. Built particularly for the backbone, the 16-slot X-Pedition 8600 switch router combines wire-speed performance at gigabit rates, pinpoint control of application flows, and superior routing capacity to ensure high availability of internal and external networks including business-critical web content, ERP applications, voice/video/data, e-commerce and more. The high-capacity X-Pedition 8600 delivers full-function, wire-speed IP/IPX routing—both unicast (IP:RIP ,OSPF , BGP , IPX:RIP) and multicast (IGMP , DVMRP , PIM-DM, PIM-SM). Powered by a non-blocking 32 Gigabit per second switching fabric, the X-Pedition 8600’s throughput exceeds 30 million packets per second and can be configured with up to 240 10/100 ports or 60 Gigabit Ethernet ports.Enterprise backbone requirements are met through massive table capacity and redundancy. The X-Pedition is also the industry’s first Gigabit switching router with WAN capabilities. The WAN interfaces extend the benefits of the X-Pedition to remote locations, providing network administrators application-level control from the desktop to the WAN edge, all at wire speed.The unique X-Pedition architecture enables you to route or switch packets based on the information in Layer 4 or on the traditional source-destination information in Layer 3. This application-level control allows the X-Pedition to guarantee security and end-to-end Quality of Service (QoS) while maintaining wire-speed throughput. QoS policies may encompass all the applications in the network, groups of users, or relate specifically to a single host-to-host application flow.•High-capacity, multilayer switch router for enterprise backbones—Full-function IP/IPX routing for unicast and multicast traffic—32 Gbps non-blocking switching fabric; 30 Mpps routing throughput —Up to 60 Gigabit Ethernet ports; up to 240 10/100 ports—Built-in support for 10 Gig, optical networks and emerging technologies •Full application support from the desktop to the WAN—Wire-speed Layer 4 application flow switching—Maintains wire-speed performance with all other features enabled —Supports HSSI, FDDI, ATM and serial WAN interfaces —Ready now for multicast voice and video applications•Pinpoint control to prioritize applications, improve e-business operation—Wire-speed, application-level QoS for end-to-end reliability —Application load balancing and content verification—Supports DiffServ, Weighted Fair Queuing and Rate Limiting (CAR)•Superior fault tolerance to ensure 24x7 network availability—Redundant power supplies and CPUs to protect from failures —Load sharing to enhance performance through redundant links•Advanced security features for greater peace of mind—Secure Harbour™ framework protects against internal and external abuse —Wire-speed Layer 2/3/4 security filters•Standards-based, intuitive management for fast, easy troubleshooting—Full support for RMON and RMON 2—Comprehensive SNMP-based management via NetSight™ AtlasThe X-Pedition 8600 is easily configured and managed through NetSight Atlas network management software,which includes plug-in applications for ACL, inventory and policy management. The X-Pedition Switch Router is fully standards-based and completely interoperable with existing networking equipment.Guaranteeing Quality of ServiceWith global enterprise more dependent than ever on the applications that support their business—from e-commerce and SAP to emerging multicast video applications—quality of service (QoS) becomes a top priority.QoS refers to a set of mechanisms for guaranteeing levels of bandwidth, maximum latency limits, and controlled interpacket timing. Enterasys’ X-Pedition 8600 delivers true standards-based QoS by integrating wire-speed Layer 4 switching with policy-based traffic classification and prioritization. Because Enterasys’ custom ASICs can read deeper into the packet, all the way to Layer 4, traffic can be identified, classified, and prioritized at the application level.Unmatched Performance with Wire-Speed Routing and SwitchingThe X-Pedition 8600 minimizes network congestion by routing more than 30 million packets per second (pps). The 32 Gbps switching fabric in the X-Pedition delivers full-function unicast and multicast wire-speed IP/IPX routing at gigabit speeds on all ports.The X-Pedition 8600’s custom ASICs switch or route traffic at wire speed based on Layer 2, Layer 3 and Layer 4 information. These ASICs also store QoS policies and security filters, providing wire-speed performance even when QoS and security filters are enabled. As a result, network managers no longer need to make compromises when it comes to performance and functionality; the X-Pedition delivers both.Application-Level QoS and Access Control—at Wire SpeedBased on Layer 2, Layer 3 and Layer 4 information, the X-Pedition allows network managers to identify traffic and set QoS policies, without compromising wire-speed performance.The X-Pedition can guarantee bandwidth on an application-by-application basis, thereby accommodating high-priority traffic even during peak periods of usage. QoS policies can be broad enough to encompass all the applications in the network, or relate specifically to a single host-to-host application flow.Unlike conventional routers, the X-Pedition’s performance does not degrade when security filters are imple-mented. Wire-speed security, obtained through 20,000 filters, enables network managers to benefit from both performance and security. Filters can be set based on Layer 2, Layer 3 or Layer 4 information, enabling network managers to control access based not only on IP addresses, but also on host-to-host application flows.Wire-Speed Multicast to Support Convergence ApplicationsThe X-Pedition’s switching fabric is capable of replicating packets in hardware, eliminating performance bottlenecks caused by conventional software-based routers. By providing the necessary infrastructure, the X-Pedition turns the network into an efficient multicast medium, supporting Protocol Independent Multicasting-Sparse Mode (PIM-SM), DVMRP and per-port IGMP .Industry-Leading CapacityLarge networks require large table capacities for storing routes, application flows, QoS rules, VLAN information and security filters. The X-Pedition 8600 provides table capacities that are an order of magnitude greater than most other solutions available today, supporting up to 250,000 routes, 4,000,000 application flows and 800,000 Layer 2 MAC addresses.How the X-Pedition Supports QoS•Wire-Speed Routing on Every Port —Removesrouting as the bottleneck and avoids “switch when you can, route when you must”schemes which are often complicated and proprietary •Massive Non-Blocking Backplane —Prevents overloaded output wires from clogging the switching hardware and isolates points of network congestion so that other traffic flows are unaffected•Large Buffering Capacity —Avoids packet loss during transient bursts that exceed output wire capacity •T raffic Classification and Prioritization —Enables policy-based QoS which guarantees throughput and minimizes latency forimportant traffic during times of congestion•Layer 4 Flow Switching —Provides application-level manageability, enabling the implementation of trueend-to-end QoS (e.g., RSVP)•Intuitive QoS Management Interface —Allows powerful QoS policies to beimplemented and maintained quickly and easily•Detailed NetworkInstrumentation —Facilitates network baselining and troubleshooting, delivering insight into the behavior of network trafficFull-function wire-speed IP/IPX routing enables the X-Pedition to scale seamlessly as the network evolves.The chassis-based X-Pedition can be configured with up to 240 10/100 ports or up to 60 Gigabit Ethernet ports. More than 4,000 VLANs, 20,000 security filters and large per-port buffers provide the capacity to handle peak traffic across even the largest enterprise backbones.Comprehensive Management for Easy Deployment, Changes and T roubleshootingVLAN Management —The X-Pedition can be configured to support VLANs based on ports and work managers can use Layer 2 VLANs with 802.1p prioritization and 802.1Q tagging, and can configure VLANs guided wizards within NetSight Atlas management software.Extensive Performance Monitoring —The X-Pedition paves the way for proactive planning of bandwidth growth and efficient network troubleshooting by providing RMON and RMON2 capabilities per port. Easy-to-Use, Java-Based Management —The X-Pedition’s rich functionality is made easy to use through NetSight Atlas, a command console that provides extensive configuration and monitoring of the X-Pedition as well as your entire Enterasys network. NetSight Atlas allows network managers to use any Java-enabled client station across the enterprise to remotely manage the X-Pedition 8600. NetSight Atlas can run on Solaris and Windows NT/2000/XP environments.Why the X-Pedition is a Better Backbone Router•Best-Selling Modular Layer 3Switch Router•Wire-Speed Performance with All Features Enabled •First to Support WAN Interfaces•Part of an Integrated End-to-End Solution•Pinpoint Application Control from the Desktop to the WAN •Multilayer Security Filters Don’t Sacrifice Performance •Award-Winning, Time-T ested Solution•Highly Manageable, Easily ConfigurableX-Pedition, NetSight and Secure Harbour are trademarks of Enterasys Networks. All other products or services mentioned are identified by the trademarks or servicemarks of their respective companies or organizations. NOTE: Enterasys Networks reserves the right to change specifications without notice. Please contact your representative to confirm current specifications.TECHNICAL SPECIFICATIONSPerformanceWire-speed IP/IPX unicast and multicast routing32 Gbps non-blocking switching fabric30 Million packets per second routing and Layer 4 switchingthroughputCapacity240 Ethernet/Fast Ethernet ports (10/100Base-TX or100Base-FX)60 Gigabit Ethernet ports (1000Base-LX or 1000Base-FX)Up to 25,000 routesUp to 4,000,000 Layer 4 application flowsUp to 800,000 Layer 2 MAC addressesUp to 250,000 Layer 3 routesUp to 20,000 security/access control filters3 MB buffering per Gigabit port1 MB buffering per 10/100 port4,096 VLANsPower System120VAC, 6A MaxRedundant CPU and power supplyHot-swappable media modulesPHYSICAL SPECIFICATIONSDimensions48.9 cm (19.25”) x 43.82 cm (17.25”) x 31.12 cm (12.25”)Weight61.75 lb. (28.0 kg)ENVIRONMENTAL SPECIFICATIONSOperating T emperature0°C to 40°C (32°F to 104°F)Relative Humidity5% to 95% noncondensingPROTOCOLS AND STANDARDSIP RoutingRIPv1/v2, OSPF, BGP-4IPX RoutingRIP, SAPMulticast SupportIGMP, DVMRP, PIM-DM, PIM-SMQoSApplication level, RSVPIEEE 802.1pIEEE 802.1QIEEE 802.1d Spanning T reeIEEE 802.3IEEE 802.3uIEEE 802.3xIEEE 802.3zRFC 1213 - MIB-2RFC 1493 - Bridge MIBRFC 1573 - Interfaces MIBRFC 1643 - Ethernet like interface MIBRFC 1163 - A Border Gateway Protocol (BGP)RFC 1267 - BGP-3RFC 1771 - BGP-4RFC 1657 - BGP-4 MIBRFC 1058 - RIP v1RFC 1723 - RIP v2 Carrying Additional InformationRFC 1724 - RIP v2 MIBRFC 1757 - RMONRFC 1583 - OSPF Version 2RFC 1253 - OSPF v2 MIBRFC 2096 - IP Forwarding MIBRFC 1812 - Router RequirementsRFC 1519 - CIDRRFC 1157 - SNMPRFC 2021 - RMON2RFC 2068 - HTTPRFC 1717 - The PPP Multilink ProtocolRFC 1661 - PPP (Point to Point Protocol)RFC 1634 - IPXWANRFC 1662 - PPP in HDLC FramingRFC 1490 - Multiprotocol Interconnect over Frame RelayORDERING INFORMATIONSSR-16X-Pedition 8600 switch router 16-slot base system includingchassis, backplane, modular fan, and a single switch fabricmodule (SSR-SF-16). Requires new CM2 Control ModuleSSR-PS-16Power Supply for the X-Pedition switch router 8600SSR-PS-16-DCDC Power Supply Module for the X-Pedition 8600SSR-SF-16Switch fabric module for the X-Pedition 8600. One moduleships with the base system (SSR-16). Order only if second isrequired for redundancy.SSR-PCMCIAX-Pedition 8600 and 8000 8MB PCMCIA card (ships with SSR-RS-ENT, second required for redundant CM configuration)SSR-CM2-64X-Pedition switch router Control Module with 64 MB memorySSR-CM3-128X-Pedition switch router Control Module with 128 MB memorySSR-CM4-256X-Pedition switch router Control Module with 256 MB memorySSR-MEM-128New CM2 memory upgrade kit (For CM2 series only)SSR-RS-ENTX-Pedition Switch Router Services for L2, L3, L4 Switchingand IP (Ripv2, OSPF) IPX (RIP/SAP) Routing. One requiredwith every chassis, shipped on PC card.© 2002 Enterasys Networks, Inc. All rights reserved. Lit. #9012476-111/02。
