...(intermediate system to immediate system and open shortest path first). • The OSPF routes (open shortest path first) in Cisco has no hop count limitations. The external for Cisco (EBGP) is 20 compares to Junos (BGP) with 170. Cisco is lower because it goes out as a AS instead of staying as a AS. The IBGP is 200 because of its internal route should be a IGP. The BGP prefers the paths learned by using the EBGP over paths learned using IBGP to eliminate loops. • distance Bgp 200 • default-metric 4 This table lists the administrative distance default values of the protocols Route Source Default Distance Values Connected interface 0 Static route 1 Enhanced Interior Gateway Routing Protocol (EIGRP) summary route 5 External Border Gateway Protocol (BGP) 20 Internal EIGRP 90 IGRP 100 OSPF 110 Intermediate System-to-Intermediate System (IS-IS) 115 Routing Information Protocol (RIP) 120 Exterior Gateway Protocol (EGP) 140 On Demand Routing (ODR) 160 External EIGRP 170 Internal BGP 200 Unknown* 255 Default Route Preference Values How Route Is Learned Default Preference Statement to Modify Default Preference Directly connected network 0 - System routes 4 - Static 5 Static MPLS 7 MPLS preference in the JUNOS MPLS Applications Configuration Guide LDF 8 LDF preference in the JUNOS MPLS Applications Configuration Guide OSPF internal route 10 OSPF export IS-IS Level 1 internal route 15 IS-IS external-preference, preference IS-IS Level 2 internal route 18 IS-IS external-preference...
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...A REPORT ON CURRENT BGP PROBLEMS AND SUGGESTED SOLUTIONS CS526- Assignment# 4 Amit Jhamb & Bhavani Prasad University of Missouri- Kansas City BGP Overview The Border Gateway Protocol (BGP) is an exterior gateway protocol (EGP) also known as inter-Autonomous System routing protocol. The primary function of a BGP speaking system is to exchange network reachability information with other BGP systems. This network reachability information includes information on the list of Autonomous Systems (ASs) that reachability information traverses. This information is sufficient to construct a graph of AS connectivity from which routing loops may be pruned and some policy decisions at the AS level may be enforced. BGP-4 provides a new set of mechanisms for supporting classless interdomain routing. These mechanisms include support for advertising an IP prefix and eliminate the concept of network "class" within BGP. BGP-4 also introduces mechanisms, which allow aggregation of routes, including aggregation of AS paths. BGP also performs interdomain routing in TCP/IP networks. Problems in BGP I-BGP Scaling Problem: All BGP speakers within a single AS must be fully meshed so that any external routing information must be re-distributed to all other routers within that AS. This "full mesh" requirement clearly does not scale when there are a large number of IBGP speakers as is common in many of todays internet networks. For n BGP speakers within an...
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...Switches and Router Christina Bennett IT242 Switches and Router One of the main reasons that Cisco is number one in the enterprise networking market place is their Internetwork Operating System (IOS).The IOS provides a similar function to Microsoft Windows or Linux: it controls and manages the hardware it is running on. Basically, the IOS provides the interface between you and the hardware, enabling you to execute commands to configure and manage your Cisco device. “Originally, the IOS was developed for Cisco routers, but over the last few years, Cisco has been porting the IOS to it so there platforms, including the Catalyst switches”. (Cisco.com) There are actually many ways of accessing a Cisco device, including the following: console, auxiliary (only certain Cisco routers), telnet, web browser, and an SNMP management station .A console interface provides serial connection access to a router— with console access, you can enter commands in a text-based mode. In order to access your Cisco device from a remote station, however, you first need to create a basic configuration, including IP addressing. Therefore, to perform your initial configurations, you need access to the console port of your Cisco device. Before you can actually begin configuring your Cisco device, you first have to connect it to your network and set up a terminal connection to its console interface. No two routers are setup in the same manner; however, the command modes they use are pretty much alike...
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...Fall 2006, Syracuse University Lecture Notes for CIS/CSE 758: Internet Security Routing Protocols (1) Introduction Static routing versus dynamic routing Static routing Fixes routes at boot time Useful only for simplest cases Dynamic routing Table initialized at boot time Values inserted/updated by protocols that propagate route information Necessary in large internets Routing with partial information The routing table in a given router contains partial information about possible destinations For the unknown destinations, forward them to the default router. Potential problem: some destinations might be unreachable. Original Internet and the problem if the core routers are allowed to have default routes. Core routing architecture with single backbone. Assumes a centralized set of routers that know all possible destinations in an internet. Non-core routers use the core routers as their default routers. Work best for internets that have a single, centrally managed backbone. Inappropriate for multiple backbones. Disadvantage Central bottleneck for all traffic Not every site could have a core router connected to the backbone: how do they get routing information? No shortcut route possible: non-core routers always forward their traffic to the default routers even though another core router provides a better route. This is because the noncore routers do not know which one is better without full knowledge of all possible destinations...
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...The Evolving Network Model EIGRP OSPF IS-IS Optimizing Routing CCNP BSCI Quick Reference Sheets Exam 642-901 BGP IP Multicast IPv6 Introduction Brent Stewart Denise Donohue ciscopress.com [2] ABOUT THE AUTHORS CCNP BSCI Quick Reference Sheets About the Authors Brent Stewart, CCNP, CCDP, MCSE, Certified Cisco Systems Instructor, is a network administrator for CommScope. He participated in the development of BSCI, and has seperately developed training material for ICND, BSCI, BCMSN, BCRAN, and CIT. Brent lives in Hickory, NC, with his wife, Karen and children, Benjamin, Kaitlyn, Madelyn, and William. Denise Donohue, CCIE No. 9566, is a Design Engineer with AT&T. She is responsible for designing and implementing data and VoIP networks for SBC and AT&T customers. Prior to that, she was a Cisco instructor and course director for Global Knowledge. Her CCIE is in Routing and Switching. © 2007 Cisco Systems Inc. All rights reserved. This publication is protected by copyright. Please see page 73 for more details. [3] ICONS USED IN THIS BOOK CCNP BSCI Quick Reference Sheets Icons Used in This Book Si Router 7507 Router Multilayer Switch with Text Multilayer Switch Communication Server Switch I DC Internal Firewall IDS Web Browser Database App Server © 2007 Cisco Systems Inc. All rights reserved. This publication is protected by copyright. Please see page 73 for more details. [4] CHAPTER 1 CCNP...
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...Impact of BGP Dynamics on Router CPU Utilization Sharad Agarwal1 , Chen-Nee Chuah2 , Supratik Bhattacharyya3 , and Christophe Diot4 1 University of California, Berkeley, USA, sagarwal@cs.berkeley.edu 2 University of California, Davis, USA, chuah@ece.ucdavis.edu 3 Sprint ATL, Burlingame, USA, supratik@sprintlabs.com 4 Intel Research, Cambridge, UK, christophe.diot@intel.com 1 Introduction The Internet is an interconnection of separately administered networks called Autonomous Systems or ASes. To reach entities outside the AS, the inter-domain routing protocol used today is the Border Gateway Protocol or BGP [1]. It has been approximately 15 years since BGP was deployed on the Internet. The number of ASes participating in BGP has grown to over 16, 000 today. However, this growth has been super-linear during the past few years [2]. With this sudden growth there has been concern in the research community about how well BGP is scaling. In particular, it has been noted that there is significant growth in the volume of BGP route announcements (or route flapping) [3] and in the number of BGP route entries in the routers of various ASes [2]. For every BGP routing update that is received by a router, several tasks need to be performed [4]. First, the appropriate RIB-in (routing information base) needs to be updated. Ingress filtering, as defined in the router’s configuration, has to be applied to the route announcement. If it is not filtered out, the route undergoes the BGP route selection...
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...Discretionary · Must be supported; propagation optional 5 Local Preference Metric for internal neighbors to reach external destinations (default 100) 6 Atomic Aggregate Includes ASes which have been dropped due to route aggregation Optional Transitive · Marked as partial if unsupported by neighbor 7 Aggregator ID and AS of summarizing router 8 Community Route tag Optional Nontransitive · Deleted if unsupported by neighbor 4 Multiple Exit Metric for external neighbors to reach the Discriminator (MED) local AS (default 0) 9 Originator ID The originator of a reflected route 10 Cluster List List of cluster IDs 13 Cluster ID Originating cluster -- Weight iBGP AD 200 Standard RFC 4271 Protocols IP Transport TCP/179 Authentication MD5 Terminology Autonomous System (AS) A logical domain under the control of a single entity External BGP (eBGP) BGP adjacencies which span autonomous system boundaries Internal BGP (iBGP) BGP adjacencies formed within a single AS Synchronization Requirement A route must be known by an IGP before it may be advertised to BGP peers Packet Types Cisco proprietary, not communicated to peers (default 0) Path Selection Attribute eBGP AD 20 Open Update Keepalive Notification Neighbor States Description Preference 1 Weight Administrative preference Highest Active · Attempting to connect 2 Local Preference Communicated between peers within...
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...Instructions: Research all of the concepts below, answer the following questions, and then respond to the questions about the configurations on pages 2 and 3. Research the following concepts: • Area border router (ABR) • Autonomous system boundary router (ASBR) • Designated router (DR ) • Backup designated router (BDR) Answer the following questions: 1. When would you use an ABR as opposed to an ASBR? The time I would use ABR as opposed to ASBR is when I want to connect one or more OSPF areas to the backbone of the Network 2. What are the effects of using two OSPF processes? The effects of using two OSPF process would be you having absolute control over what prefixes are advertised between the two OSPF processes 3. What is the difference between a DR as opposed to BDR? DR and Bdr concept work in broadcast multi access network. It reduces Lsa flooding within broadcast domain by electing one DR and Bdr to which other routers in broadcast domain Form adjacency. So that only Dr and BDR have full adjacency That means full link state database. 4. How does the election process work? a network with 3 OSPF routers on a Fast Ethernet network. They are connected to the same switch (multi-access network) so there will be a DR/BDR election. OSPF has been configure so all routers have become OSPF neighbors, Instructions: a is ABSR B is ABR...
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...Category | Points | Description | Section 1Configuring OSPF Single Area: 40 Points * Task 1: Step 5 * Related Explanation or Response * Task 1: Step 6 * Related Explanation or Response * Task 1: Step 10 * Related Explanation or Response * Task 2: Step 4 * Related Explanation or Response * Summary Paragraph | 2323232320 | Paste the requested screenshot.Provide the requested answer.Paste the requested screenshot.Provide the requested answer.Paste the requested screenshot.Provide the requested answer.Paste the requested screenshot.Provide the requested answer.In your own words, summarize what you have learned about IP subnetting and configuration. | Total | 40 | | ------------------------------------------------- Name: Date: Professor: ------------------------------------------------- Configuring OSPF Single Area vLab (30 points) Write a paragraph (minimum five college-level sentences) below that summarizes what was accomplished in this lab, what you learned by performing it, how it relates to this week’s TCOs and other course material, and (just as important) how you feel it will benefit you in your academic and professional career. (10 points) ------------------------------------------------- Copy and paste the following screenshots from your Configuring OSPF Single Area lab below. Task 1, Step 5: Paste a screenshot showing the route table of the Indianapolis router. (2 points) Question: Based on the information...
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...NETW204: Assignment 4, Link-state Routing and OSPF (50 points) Fill in the blanks below with either the term defined or the definition for the terms listed. Each answer is worth 2 points each, 25 questions X 2 = 50 total points. Type answers in the appropriate cell; text will automatically wrap. Post your completed assignment to the dropbox. NAME | Chad White | | Term | Definition | 1 | ABR | Attaches to multiple areas, maintains separatelink-state databases for each area it is connectedto, and routes traffic destined for or arriving fromother areas | 2 | Autonomous System Boundary Router (ASBR) | Routers that have at least one interface attached to an external internetwork (another autonomous system [AS]), such as a non-OSPF network. ASBRs can import non- OSPF network information to the OSPF network and vice versa; this process is called route redistribution. | 3 | Backup Designated Router (BDR) | Used to provide redundancy in broadcast networks which are utilizing the OSPF | 4 | DBD | Contains an abbreviated list of the sendingrouter’s link-state database and is used by receiving routers to check against the local link-state database | 5 | Designated Router (DR) | A router that informs end nodes of the existence and identity of other routers. | 6 | DRothers | Routers that are not a dr or bdr. they are the routers in the ospf network. | 7 | Flapping link | A link which cycles between up and down. | 8 | Highest active IP | Router ID for an OSPF...
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...Implementing Cisco IP Routing (642-902) Exam Description: The Implementing Cisco IP Routing (ROUTE 642-902) is a qualifying exam for the Cisco Certified Network Professional CCNP®, Cisco Certified Internetwork Professional CCIP®, and Cisco Certified Design Professional CCDP® certifications. The 2-hour, 45-55 question exam will certify that the successful candidate has the knowledge and skills necessary to use advanced IP addressing and routing in implementing scalable and secure Cisco ISR routers connected to LANs and WANs. The exam also covers configuration of secure routing solutions to support branch offices and mobile workers. The exam is closed book and no outside reference materials are allowed. The following topics are general guidelines for the content likely to be included on the exam. However, other related topics may also appear on any specific delivery of the exam. In order to better reflect the contents of the exam and for clarity purposes, the guidelines below may change at any time without notice. 25% 1.0 1.1 1.2 1.3 1.4 1.5 1.6 25% 2.0 2.1 2.2 2.3 2.4 2.5 2.6 5% 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Implement an EIGRP Based Solution, Given a Network Design and a Set of Requirements Determine network resources needed for implementing EIGRP on a network Create an EIGRP implementation plan Create an EIGRP verification plan Configure EIGRP routing Verify EIGRP solution was implemented properly using show and debug commands Document results of EIGRP implementation and verification...
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...OPTIMAL PACKET ROUTING Abstract- The optimal routing is the determination of the optimal routing policy that is the set of routes on which packets need to be transmitted in order to reduce the delay, cost and throughput. The routing optimization problem is an important tool in the optimization of both the operational capabilities and the design of large scale commuter communications networks. Resource requirements are not taken into account for conventional routing algorithms. The problem of finding optimal routes in a packet switched computer can be done using non linear multi commodity flow problem. The mathematical programming technique which is applied for the solution of routing problem for large networks is inefficient output. By using Heuristic methods satisfactory results can be obtained. But using Heuristic technique the results are not always optimal and may have some limitations. To overcome all this we can use decomposition method which is very efficient for computation and results are nearly exact. Introduction- Routers are basically classified into two types- Oblivious and Adaptive. In oblivious routing the path is completely determined by the sources and destination. Whereas Deterministic routing is the same path is chosen between a source and destination. The nature of deterministic routing is distributed that is each node makes its routing decisions independent of others which make routing simple and fast and this is widely used in most of the networks...
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...NETW204: Assignment 4, Link-state Routing and OSPF (50 points) Fill in the blanks below with either the term defined or the definition for the terms listed. Each answer is worth 2 points each, 25 questions X 2 = 50 total points. Type answers in the appropriate cell; text will automatically wrap. Post your completed assignment to the dropbox. NAME | Jose Antonio Nunez | | Term | Definition | 1 | An OSPF network | Attaches to multiple areas, maintains separatelink-state databases for each area it is connectedto, and routes traffic destined for or arriving fromother areas | 2 | Autonomous System Boundary Router (ASBR) | Is an OSPF router located between OSPF autonomous system networks and non-OSPF networks. | 3 | Backup Designated Router (BDR) | Is a router that becomes the Designated Router if the DR fails. | 4 | Database Description (DBD) | Contains an abbreviated list of the sendingrouter’s link-state database and is used by receiving routers to check against the local link-state database | 5 | Designated Router (DR) | Is an OSPF router that controls the routes of LSA’s or LSU’s. It helps maintain link state updates to other routers in the network. | 6 | DRothers | Is neither a DR, nor a BDR. They are other routers in the OSPF network. | 7 | Flapping link | Is when an advertised route between two nodes alternates back and forth. This creates a link state that cycles between up and down. | 8 | The highest IP address of an active router interface...
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...BGP PART 1 Attribute Types Must be supported and propagated Must be supported; propagation optional packetlife.net About BGP Type Path Vector eBGP AD 20 iBGP AD 200 Standard RFC 4271 Protocols IP Transport TCP/179 Authentication MD5 Terminology Autonomous System (AS) A logical domain under the control of a single entity Well-known Mandatory Well-known Discretionary Optional Transitive Marked as partial if unsupported by neighbor Deleted if unsupported by neighbor Attributes Optional Nontransitive Name Type Description Aggregator OT AS Path WM Atomic Aggregate WD Cluster ID ON Community OT Local Preference WD Multiple Exit ON Discriminator (MED) Next Hop WM Origin WM Originator ID ON Weight O ID and AS of router which performed summarization List of autonomous systems which the advertisement has traversed Includes ASes which have been dropped due to route aggregation Originating cluster Route tag Metric for internal neighbors to reach external destinations (default 100) Metric for external neighbors to reach the local AS (default 0) External peer in neighboring AS Origin type (IGP, EGP, or unknown) Identifies a route reflector Cisco proprietary, not communicated to peers (default 0) Path Selection External BGP (eBGP) BGP adjacencies which span autonomous system boundaries Internal BGP (iBGP) BGP adjacencies formed within a single autonomous system Synchronization Requirement A route must be known by an IGP before it may be advertised...
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...minimal downtime during the transition. Example.com is running EIGRP while Example.net is running a multi-area OSPF. Because it is imperative that the two booksellers continuously deliver Internet services, you should bridge these two routing domains without interfering with each router’s path through its own routing domain to the Internet. The CIO determines that it is preferable to keep the two protocol domains shown in the diagram during the transition period, because the network engineers on each side need to understand the other’s network before deploying a long-term solution. Redistribution will be a short-term solution. In this scenario, R1 and R2 are running EIGRP while R2 is the OSPF autonomous system border router (ASBR) consisting of areas 0, 10, and 20. You need to configure R2 to enable these two routing protocols to interact to allow full connectivity between all networks. In this lab, R1 is running EIGRP and R3 is running multi-area OSPF. Your task is to configure redistribution on R2 to enable these two routing protocols to interact, allowing full connectivity between all networks. In Appendix A of this lab, you explore the black hole operation. Note: This lab uses Cisco 1941 routers with Cisco IOS Release 15.2 with IP Base. Depending on the router or switch...
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