Dynamic Routing Tables Using Simple Balanced Search Trees
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ENetwork Chapter 5 - CCNA Exploration: Network Posted by Space on Sunday, May 10, 20091In an IPv4 environment, what information is used by the router to forward data packets from one interface of a router to another?**destination network addresssource network addresssource MAC addresswell known port destination address2What information is added during encapsulation at OSI Layer 3?source and destination MACsource and destination application protocolsource and destination port number**source and destination IP address3In a connectionless system, which of the following is correct?The destination is contacted before a packet is sent.**The destination is not contacted before a packet is sent.The destination sends an acknowledgement to the source that indicates the packet was received. The destination sends an acknowledgement to the source that requests the next packet to be sent.4Which IP packet field will prevent endless loops?type-of-serviceidentificationflags**time-to-liveheader checksum5Which portion of the network layer address does a router use to forward packets?host portionbroadcast address**network portiongateway address6Refer to the exhibit. Using the network in the exhibit, what would be the default gateway address for host A in the 192.133.219.0 network?192.135.250.1192.31.7.1192.133.219.0**192.133.219.17If the default gateway is configured incorrectly on the host, what is the impact on communications? The host is unable to communicate on the local network.**The host can communicate with other hosts on the local network, but is unable to communicate with hosts on remote networks.The host can communicate with other hosts on remote networks, but is unable to communicate with hosts on the local network.There is no impact on communications.8What is the purpose of a default gateway?physically connects a computer to a networkprovides a permanent address to a computeridentifies the network to which a computer is connectedidentifies the logical address of a networked computer and uniquely identifies it to the rest of the network**identifies the device that allows local network computers to communicate with devices on other networks9What type of routing uses information that is manually entered into the routing table?dynamicinterior**staticstandard10When the destination network is not listed in the routing table of a Cisco router, what are two possible actions that the router might take? (Choose two.)The router sends an ARP request to determine the required next hop address.**The router discards the packet.The router forwards the packet toward the next hop indicated in the ARP table.The router forwards the packet to the interface indicated by the source address.**The router forwards the packet out the interface indicated by the default route entry.11What are the key factors to consider when grouping hosts into a common network? (Choose three.) gateways**purposephysical addressingsoftware version**geographic location**ownership12What is a component of a routing table entry?the MAC address of the interface of the routerthe destination Layer 4 port numberthe destination host address**the next-hop address13Which intermediary devices could be used to implement security between networks? (Choose two.) **routerhubswitch**firewallaccess pointbridge14What are three common problems with a large network? (Choose three.)too few broadcasts**performance degradation**security issueslimited management responsibility**host identificationprotocol compatibility15Refer to the exhibit. All devices shown in the exhibit have factory default settings. How many broadcast domains are represented in the topology that is shown?3**45781116Which three statements are true about routes and their use? (Choose three.)If no route to the destination network is found, the packet is returned to the previous router.**If the destination network is directly connected, the router forwards the packet to the destination host.If multiple network entries exist for the destination network, the most general route is used to forward the packet.**If no route exists for the destination network and a default route is present, the packet is forwarded to the next-hop router.**If the originating host has a default gateway configured, the packet for a remote network can beforwarded using that route.If a host does not have a route manually configured for the destination network, the host will drop the packet.17Refer to the exhibit. A network administrator is troubleshooting a connectivity problem and needs to determine the address that is used to forward network packets out the network. Using the netstat -r command, the administrator would identify which address as the address to which all hosts send packets that are destined for an outside network?10.10.10.26127.0.0.1**10.10.10.610.10.10.1224.0.0.018Refer to the exhibit. A network administrator notices that there are too many broadcasts on the network. What two steps can the network administrator take to resolve this problem? (Choose two.) **Replace S2 with a router.Place all servers on S1.Disable TCP/IP broadcasts.**Subnet the 192.168.0.0 /24 network.Disable all unused interfaces on the switches.19Refer to the exhibit. The network in the exhibit is fully operational. What two statements correctly describe the routing for the topology that is shown? (Choose two.)**192.168.0.2 is the next-hop address that is used by R3 to route a packet from the 10.0.0.0 network to the 172.16.0.0 network.10.0.0.1 is the next-hop address that is used by R1 to route a packet from the 192.168.12.0 network to the 10.0.0.0 network.192.168.0.1 is the next-hop address that is used by R1 to route a packet from the 192.168.12.0 network to the 172.16.0.0 network.172.16.0.1 is the next-hop address that is used by R3 to route a packet from the 10.0.0.0 to the 172.16.0.0 network.**192.168.0.1 is the next-hop address that is used by R2 to route a packet from the 172.16.0.0 network to the 192.168.12.0 network.192.168.0.2 is the next-hop address that is used by R2 to route a packet from the 172.16.0.0 network to the 192.168.12.0 network.20What two characteristics are commonly associated with dynamic routing protocols? (Choose two.) require no device configuration**provide routers with up-to-date routing tablesrequire less processing power than static routes require**consume bandwidth to exchange route informationprevent manual configuration and maintenance of the routing table21What statement describes the purpose of a default route?A host uses a default route to transfer data to another host on the same network segment.A host uses a default route to forward data to the local switch as the next hop to all destinations.A host uses a default route to identify the Layer 2 address of an end device on the local network. **A host uses a default route to transfer data to a host outside the local network when no other route to the destination exists.。
Cisco Centified Network Associate 640-801 Course Note written by [Ka\(^oo^)/Ka]@sjtunimo Page 1 of 114ForewordCisco certified network Associate(CCNA)是一门相当基础的网络认证课程,相对来说,前3章都是很基础的东西,但却十分重要,希望读者能够认认真真地看下去,这样对后面学习很有帮助,相对而言,搞清楚了这些网络基础,后面上手就很快了。
当然这只是kaka的准备CCIE的第一份笔记,当然也对很多只想考CCNA 的人很有帮助,以后根据我的学习进度,会进一步的加入CCNP和CCIE的一些笔记。
对于要考CCNA的人呢,我推荐几本书,Sybex <CCNA study Guide 5.0>Cisco Networking Academy .英文好些的,可以看原版,差一点的看中文版吧<不过中文版翻译很垃圾的哦>,所以,很多keywords,我在记笔记的时候都用英文标识出来了,也是方便大家更好的参加考试。
同时,推荐大家一款软件BosonSoftware Netsim 6.0 beta3, 它可以极好的模拟整个ccna ccnp的考试环境,同时还有相当高的自由度,用于组建一个模拟的CCIE lab.但是和真实设备比起来,Debug,WAN protocol支持等,还有不足。
在此,我还要感谢那些支持我的人,感谢上海交通大学网络中心,上海交通大学网管部对我的支持,谢谢你们。
给我了一个可以触摸Cisco R&S实物的机会,同时也要感谢Nichole,谢谢你让我明白了,自己真的该做什么。
再也不会像以前那个成天游手好闲的小屁孩了,要做四有新人~这篇foreword,写得不好,没有豪言壮语,没有刻意提起一些名人名言。
其实生活也应该这样,低调平凡一些,用真心去感谢那些真正帮助过你的人们。
Abbreviations:LAN Local Area Network 局域网MAN Metropolitan Area Network 城域网PAN personal area network 个人局域网WAN Wide Area Network 广域网VLAN Virtual Local Area Network 虚拟局域网OSI/RM Open System Interconnection Reference Model开放系统互连参考模型UTP Unshielded Twisted Pair 非屏蔽双绞线SNR Sigal-to-Noise Ratio信噪比FDM Frequency Division Multiplexing 频分多路复用TDM Time Division Multiplexing 时分多路复用WDM Wave length Division Multiplexing波分复用CDMA Code Division Multiple Access 码分多址CSMA/CD Carrier Sense Multiple Access with Collision Detection 载波侦听多路访问/冲突检测CSMA/CA Carrier Sense Multiple Access with Collision Avoidance 载波侦听多路访问/冲突避免RTS Request To Send请求发送CTS Clear To Send 清除发送MAC Media Access Control 介质访问控制PCM Pulse Code Modulation 脉冲编码调制QAM Quadrature Amplitude Modulation 正交振幅调制QPSK Quadrature Phase Shift Keying 正交相移键控ADSL Asymmetric Digital Subscriber Line 非对称数字用户环路CRC Cyclic Redundancy Check 循环冗余校验VC Virtual Circuit 虚电路ATM Asynchronous Transfer Mode 异步传输模式PPP Point to Point Protocol 点对点协议HLDC High-Level Data Link Control 高级数据链路控制RIP Routing Information Protocol 路由信息协议RTT Round-Trip Time 往返时延CIDR Classless Inter-Domain Routing 无类别域间路由IP Internet Protocol 网络之间互连的协议TTL Time To Live 生存时间MTU Maximum Transmission Unit 最大传输单元ICMP Internet Control Message Protocol 网络控制报文协议UDP User Datagram Protocol 用户数据报协议ARP Address Resolution Protocol 地址解析协议DHCP Dynamic Host Configuration Protocol 动态主机配置协议NAT Network Address Translation 网络地址转换RPC Remote Procedure Call 远程过程调用OSPF Open Shortest Path First 开放式最短路径优先BGP Border Gateway Protocol 边界网关协议TCP Transmission Control Protocol 传输控制协议RTP Real-time Transpo rt P rotocol 实时传输协议FTP File Transfer Protocol 文件传输协议SMTP Simple Mail Transfer Protocol 简单邮件传输协议POP3 Post Office Protocol - Version 3 邮局协议版本3IAMP internet message access protocol 因特网信息报文存取协议?不知道对不对IMAP Internet Mail Access Protocol Internet邮件访问协议DNS Domain Name System 域名系统URL Uniform Resoure Locator 统一资源定位器HTTP Hyper Text Transfer Protocol 超文本传输协议WWW World Wide Web 万维网1、Basic and important concepts or notations●network architecture, layers, protocols●OSI/RM, TCP/IP reference model, main tasks of data link/network/transportlayers, protocols at each layer of TCP/IP model●PAN, LAN, WAN, VLAN, WLAN●bandwidth, link capacity●multiplexing, channel allocation●Frame, Ethernet frame format, MAC address●framing method:character-count, byte-stuffing, bit-stuffing, flag byte●Connection/connectionless service, circuit switching/packet switching,●Error Control coding, Hamming distance●Hamming code, even-parity /odd-parity●CRC, generator polynomial, remainder●stop-and-wait protocols, sliding window, go-back-n, selective-repeat, piggyback ●CSMA/CD●hidden station problem, exposed station problem, CSMA/CA●hub/repeater /switch/bridge/router/gateway.●routing algorithm, Distance vector routing, link state routing●IP address, classful and special addressing, CIDR, subnetting/aggregation,mask/prefix●routing table/forwarding,●packet, IPv4 header●NAT, 3 reserved private IP address ranges●TCP, port/port number, TCP header, three-way handshake●congestion control, ECN/RED, AIMD/slow start, congestion window, threshold●DNS system, domain name resolution2、Computations●Nyquist law, Shannon law, PCM●FDM, CDMA●bit-stuffing, byte-stuffing, character-count●Hamming code, CRC●CSMA/CD,minimal frame size●Distance vector routing algorithm●CIDR, aggregation●forwarding in routers, longest matching11 What is the principal difference between connectionless communication andconnection-oriented communication?Connection-oriented communication has three phases. In the establishment phase, a request is made to set up a connection. Only after this phase has been successfully completed can the data transfer phase be started and data transported. Then comes the release phase.Connectionless communication does not have these phases. It just sends the data.16 把比特流转化为帧OSI 数据链路层TCP/IP :链路层决定哪条路径通过子网OSI 网络层TCP/IP 互联网层20 What is the main difference between TCP and UDP.Answer:The first one, TCP (Transmission Control Protocol), is a reliableconnection-oriented protocol that allows a byte stream originating on one machine to be delivered without error on any other machine in the Internet.The second protocol, UDP (User Datagram Protocol), is an unreliable, connectionlessprotocol for applications that do not want TCP's sequencing or flow control and wish to provide their own.TCP是transmission control protocol传输控制协议,UDP是user data gram protocol用户数据电报协议。
51.What can a network administrator utilize by using PPP Layer 2 encapsulation? (Choose three.)A. VLAN supportB. compressionC. authenticationD. sliding windowsE. multilink supportF. quality of serviceAnswer: BCE解释一下:PPP协议是能支持认证的,包括PAP和CHAP;PPP还支持压缩功能和差错校验,还可实现多链路捆绑。
而他们的这些功能都是HDLC所没有的。
52.Refer to the exhibit. What is the meaning of the term dynamic as displayed in the output of the show frame-relay map command shown?A. The Serial0/0 interface is passing traffic.B. The DLCI 100 was dynamically allocated by the router.C. The Serial0/0 interface acquired the IP address of 172.16.3.1 from a DHCP server.D. The DLCI 100 will be dynamically changed as required to adapt to changes in the Frame Relay cloud.E. The mapping between DLCI 100 and the end station IP address 172.16.3.1 was learned through Inverse ARP.Answer: E解释一下:这是个关于MAP的知识。
多协议标记交换MPLS多协议标记交换xx?12?4MPLS/JYHxx1MPLS Multi?Protocol LabelSwitch?京邮电大学计算机科学与技术学院宽带网研究中心金跃辉主要内容xx?12?4MPLS/JYHxx2?MPLS基本思想?MPLS基本功能、工作原?、网络结构?MPLS核心技术?标记分配和标记交换技术、LDP、LSP?MPLS服务?显示?由、VPN、流?工程、QoSMPLSxx?12?4MPLS/JYHxx3提出的动机?Inter的高速发展和新业务的出现,对基于IP的承载网提出了挑战?各种IP与ATM融合的技术都无法全面解决现有问题,但这些IP交换解决方案都意识到将选?和交换结合起来的优势?当前的网络技术提供的VPN解决方案都存在缺陷,?能适应VPN市场的快速发展?网络向宽带化、智能化和一体化方向发展MPLSxx?12?4MPLS/JYHxx4标准化?IETF的MPLS工作组?主要目标是开发一个综合选?和交换的标准,把?由选择功能转移到网络边缘,把效率?高、结构?简单的交换功能放在核心网络中?可以运??同的链?层技术,如ATM、FR、PPP、POS、LAN等?实际上,网络层协议只限于IPv4和IPv6?ITU?T的SG11、SG13、SG15?MPLS ForumMPLSxx?12?4MPLS/JYHxx5IP ForwardingLABELSWITCHINGIP ForwardingIPIP#L1IP#L2IP#L3IP基本思想:边缘?由、核心交换MPLSMPLS/JYHxx6网络结构Label EdgeRoutersLabelSwitchingRouters(LSRsMPLSxx?12?4MPLS/JYHxx7术语?FEC:Forwarding EquivalenceClass?LSR:Label SwitchingRouter?LER:Label EdgeRouter?LDP:Label DistributionProtocol?LSP:Label SwitchedPath转发等价类xx?12?4MPLS/JYHxx8FEC(1)?在相同?径上转发,?由器以相同方式处?的一组IP分组,可以映射到同一标记?FEC可以?解为一系列属性的集合?常见的属性包括地址前缀、主机地址等?确定FEC的原则?分组具有相同的地址前缀、相同的主机地址或相同的QoS要求等转发等价类xx?12?4MPLS/JYHxx9分组去往的目的地?同,但可以映射到一条公共通?上IP1IP2IP1IP2LSRLSRLERLERLSPIP1#L1IP2#L1IP1#L2IP2#L2IP1#L3IP2#L3FEC (2)标记交换?由器xx?12?4MPLS/JYHxx10LSR(1)?Label SwitchingRouter?运?传统IP选?协议,完成?由控制功能,?新和维护?由表?运?MPLS控制协议,以与邻接设备协调FEC/标记的绑定信息,建立和维护标记转发表LIB,支持标记交换?可以利用传统交换机扩充IP选?;或将一个传统?由器升级支持MPLS标记交换?由器xx?12?4MPLS/JYHxx11LSR(2)?由协议(OSPF,BGP)标记信息库LIB应用接口TCP/IP?由表ATM等交换结构硬件转发接口数据转发单元标记交换?径LSP控制单元MPLS控制管?(LDP,RSVP等)标记边缘?由器xx?12?4MPLS/JYHxx12LER?Label EdgeRouter?完成连接MPLS域和非MPLS域以及?同MPLS域的功能?进?FEC划分,与内部MPLSLSR交换FEC/标记绑定信息?给分组加标记或剥去标记?也可用于确定业务类型,实现策略管?,接入流?工程控制等标记xx?12?4MPLS/JYHxx13?简短而长度固定的标识符,用于识别转发等价类FEC,将一个标记指派给一个FEC称为标记绑定(Binding)?只在本地有意义,经每一跳后标记是变化的,但经逻辑级联就构成LSP,类似于VPI/VCI构成PVC?标记的格式依赖于分组封装所在的介质,MPLS允许在LSP的?同部分使用?同的封装技术标记封装xx?12?4MPLS/JYHxx14LabelMPLSATM FREther PPPVPIVCI DLCI“Shim Label”L2“ShimLabel”…….IP|PAYLOADL3MPLS专用硬件/软件MPLSxx?12?4MPLS/JYHxx15标记格式Label(标记):20bitsEXP(实验字段):3bitsS(栈底指示符):1bitTTL(生存期字段):8bitsLabel EXPS TTLShimLabel共32bits标记堆栈xx?12?4MPLS/JYHxx16?分组可以携带多个标记,这些标记在分组中以堆栈的形式存在?标记堆栈的层数叫标记堆栈的”深度”,对标记堆栈的操作按照”后进先出”的原则进?;决定如何转发分组的标记始终是栈顶标记?当分组第一次进入MPLS域时,将标记插入分组头的操作为”标记入栈”;当分组离开MPLS域时,标记将被删除,称为”标记弹栈”?标记堆栈简化了标记交换?由器的运作,达到分层次选?的目的。
tunnel(GRE隧道)VPN配置过程分析Tunnel (GRE tunnel) VPN Configuration Process AnalysisIntroduction:Virtual Private Networks (VPNs) are widely used to establish secure and private connections over a public network, such as the internet. One common type of VPN is the tunnel (GRE tunnel) VPN, which utilizes Generic Routing Encapsulation (GRE) to encapsulate and transmit data packets between two remote networks. This article will analyze the configuration process of a tunnel VPN, focusing on the steps involved and the key considerations to ensure a successful setup.Configuration Process:1. Requirements analysis:Before starting the configuration process, it is crucial to determine the specific requirements of the VPN. This includes identifying the remote networks that need to be connected, the types of data to be transmitted, and any security measures that must be implemented.2. Network topology design:Based on the requirements analysis, a network topology design needs to be created. This design outlines the physical and logical layout of the network, including the placement and configuration of routers, firewalls, and VPN gateways.3. Selection of VPN gateways:In the case of tunnel VPNs, specific VPN gateways capable of supporting GRE tunneling must be selected. These gateways act as endpoints for the VPN connections, allowing data packets to be encapsulated and securely transmitted through the tunnel.4. Configuration of routers:The next step involves configuring the routers at both ends of the VPN connection. This includes assigning IP addresses to the router interfaces, enabling GRE tunneling, and setting up routing tables to ensure proper forwarding of data packets.5. GRE tunnel creation:Once the routers are configured, the GRE tunnels can be created. This involves specifying the source and destination IP addresses of the tunnel endpoints, as well as assigning a tunnel interface to facilitate the encapsulation and decapsulation of data packets.6. Encryption and authentication configuration:To enhance the security of the VPN connection, encryption and authentication mechanisms should be implemented. Popular protocols like IPsec can be utilized to encrypt the data traffic and establish secure communication between the remote networks.7. Testing and troubleshooting:After completing the configuration steps, it is crucial to test the VPN connection thoroughly. This includes verifying connectivity between the remote networks, testing data transmission, and ensuring that all securitymeasures are working as intended. If any issues are encountered, troubleshooting techniques should be employed to identify and resolve the problems.Key Considerations:1. Security:When configuring a tunnel VPN, it is essential to prioritize security. This includes selecting strong encryption algorithms, implementing authentication mechanisms, and regularly updating the VPN gateways and routers with the latest security patches.2. Scalability:The VPN design should be scalable to accommodate future growth and changes in network requirements. This can be achieved by using dynamic routing protocols, such as OSPF or BGP, which can dynamically adapt to network changes and optimize the routing process.3. Performance:Proper bandwidth planning and traffic prioritization should be considered to ensure optimal performance of the tunnel VPN. Analyzing the expected data volume and bandwidth requirements can help prevent congestion and maintain a high-quality connection.4. Redundancy:To minimize the risk of a single point of failure, redundancy measures, such as implementing redundant VPN gateways and routers, should beconsidered. This can help ensure continuous operation of the tunnel VPN, even in the event of hardware failures or network disruptions.Conclusion:Configuring a tunnel (GRE tunnel) VPN involves a systematic approach that includes requirements analysis, network topology design, selection of VPN gateways, router configuration, GRE tunnel creation, encryption and authentication configuration, as well as testing and troubleshooting. By considering key factors such as security, scalability, performance, and redundancy, a well-designed tunnel VPN can provide secure and reliable connectivity between remote networks.。
Dynamic Routing Tables Using Simple Balanced Search Trees
Y.-K. Chang and Y.-C. Lin Department of Computer Science and Information Engineering National Cheng Kung University Tainan, Taiwan R.O.C. ykchang@mail.ncku.edu.tw
Abstract. Various schemes for high-performance IP address lookups have been proposed recently. Pre-computations are usually used by the special designed IP address lookup algorithms for better performance in terms of lookup speed and memory requirement. However, the disadvantage of the pre-computation based schemes is that when a single prefix is added or deleted, the entire data structure may need to be rebuilt. Rebuilding the entire data structure seriously affects the lookup performance of a backbone router and thus not suitable for dynamic routing tables. In this paper, we develop a new dynamic routing table algorithm. The proposed data structure consists of a collection of balanced binary search trees. The search, insertion, and deletion operations can be finished in O(log N) time, where N is the number of prefixes in a routing table. Comparing with the best existing dynamic routing table algorithm which is PBOB (Prefix Binary tree On Binary tree), our experiment results using the realistic routing tables show that the proposed scheme performs better than PBOB in terms of lookup, insertion, deletion, and memory requirement.
Keywords:IP address lookup, dynamic routing table, fast update, precomputation 1. Introduction To handle gigabit-per-second traffic rates, the current backbone routers must be able to forward millions of packets per second at each port. The IP address lookup is the most critical task in the router. When a router receives a packet, the destination address in the packet’s header is used to lookup the routing table. There may be more than one route entries in the routing table that match the destination address. Therefore, it may require some comparisons with every route entries to determine which one is the longest matching. The longest route from all the matched entries is called the longest prefix match (LPM). The IP address lookup problem becomes a longest prefix matching problem. To design a good IP address lookup scheme, we should consider four key aspects: lookup speed, storage requirement, update time and scalability. For any scheme, it is hard to perform well in all aspects. The update process is the concern of this paper. Currently, the Internet has a peak of a few hundred BGP updates per second. Thus, the address lookup schemes with fast update time are desirable to avoid routing instabilities. These updates should interfere little with normal address lookup operation. Various algorithms for high-performance IP address lookup have been proposed. In the survey paper [10], a large variety of routing lookup algorithms are classified and their complexities of worst case lookup, update, and memory references are compared. Despite the intense research that has been conducted in recent years, there should be a balance between lookup speed, memory requirement, update, and scalability for a good IP address lookup scheme. The pre-computation [2], [3], [5], [8], [11] perform a lot of pre-computation and thus improve the performance of the lookup speed and memory requirement. However, a disadvantage of the pre-computation is that when a single prefix is added or deleted, the entire data structure may need to be rebuilt. Rebuilding the routing tables seriously affects the update performance of a backbone router. Thus, the schemes based on pre-computation are not suitable for dynamic routing tables. On the other hand, schemes based on the trie data structure like binary trie, multi-bit trie and Patricia trie [9] do not use pre-computation; however, their performances grow linearly with the address length, and thus the scalability of these schemes is not good when switching to IPv6 or large routing table. Although schemes like [4], [6], [12] develop a search tree data structure that is suitable for the representation of dynamic routing tables, the complex data structure leads to the memory requirement expanded and reduce the performance of lookup. Sahni and Kim [4] developed a data structure, called a collection of red-black tree (CRBT), that supports three operations for dynamic routing table of N prefixes (longest prefix match, prefix insert, prefix delete) in O(log N) time each. In [6], Lu and Sahni developed a data structure called BOB (Binary tree On Binary tree) for dynamic routing tables. Based on the BOB, data structures PBOB (Prefix BOB) and LMPBOB (Longest Matching Prefix BOB) are also proposed for highest-priority prefix matching and longest-matching prefix. On practical routing tables, LMPBOB and PBOB permit longest prefix matching in O(W) and O(log N), where W is 32 for IPv4 or 128 for IPv6. For the insertion and delete operations, they both take O(log N) time. Suri et al. [12] have proposed a B-tree data structure called multiway range tree. This scheme achieves the optimal lookup time of binary search, but also can be updated in logarithmic time when a prefix is inserted or deleted. In this paper, we develop a data structure based on a collection of independent balanced search trees. Unlike the augmented data structures proposed in the literature, the proposed scheme can be implemented with any balanced tree algorithm without any modification. As a result, the proposed data structure is simple and has a better performance than PBOB we compared. The rest of the paper is organized as follows. Section 2 presents a simple analysis for the routing tables. Section 3 illustrates proposed scheme based on the analysis in section 2 and the detailed algorithms. The results of performance comparisons using real routing tables are presented in section 4. Finally, a concluding remark is given in the last section.