Configuring BGP on Cisco Routers Volume 1

Transcription

1 Volume 1 I. Course Introduction A. Overview/Learner Skills and Knowledge B. Course Flow C. Additional References 1. Cisco Glossary of Terms D. Your Training Curriculum II. BGP Overview III. Introducing BGP B. Interdomain Routing 1. Example: Why External Routing Protocols C. BGP Characteristics D. Single-Homes Customers E. Multihomed Customers F. Transit Autonomous Systems G. BGP Limitations IV. Understanding BGP Path Attributes B. BGP Path Attributes C. Well-Known BGP Attributes D. Optional BGP Attributes E. AS-Path Attribute 1. Example: AS-Path Attribute F. Next-Hop Attribute 1. Example: Next-Hop Attribute V. Establishing BGP Sessions B. BGP Neighbor Discovery 1. Example: BGP Neighbor Discovery C. Establishing a BGP Session D. BGP Keepalives 1. Example: Keepalive Value E. MD5 Authentication F. Summary VI. Processing BGP Routes B. Receiving Routing Updates C. Building the BGP Table D. BGP Route Selection Criteria 1. Example: BGP Route Selection Criteria E. BGP Route Propagation F. Building the IP Routing Table G. Advertising Local Networks 1. Example: Advertising Local Networks H. Automatic Summarization 1. Example: Automatic Summarization 1

2 I. Summary VII. Configuring Basic BGP B. BGP Routing Process 1. router bgp C. Configuring External Neighbors 1. neighbor remote-as 2. neighbor description 3. neighbor shutdown D. Configuring BGP Timers 1. timers bgp 2. neighbor timers E. Configuring MD5 Authentication 1. neighbor password F. Announcing Networks in BGP 1. Example: Announcing Networks in BGP G. Redistributing Routes into BGP 1. redistribute (IP) 2. distribute-list out (IP) H. Configuring Classless BGP 1. network (BGP) 2. Example: Configuring Classless BGP I. Aggregating BGP Networks 1. aggregate-address 2. Example: Aggregation J. BGP Conditional Route Injection 1. bgp inject-map exist-map K. BGP Support for TTL Security Check 1. neighbor ttl-security L. Multihomed Customer Problem M. Summary VIII. Monitoring and Troubleshooting BGP B. Monitoring Overall BGP Routing 1. show ip bgp summary C. Monitoring BGP Neighbors 1. show ip bgp neighbors D. Monitoring the BGP Table 1. show ip bgp E. Debugging BGP F. BGP Session Startup Problems G. BGP Neighbor Not Reachable 1. Example: BGP Neighbor Not Reachable H. BGP Neighbor Not Configured 1. Example: BGP Neighbor Not Configured I. Summary J. Module Summary K. Module Self-Check 1. Module Self-Check Answer Key IX. BGP Transit Autonomous Systems X. Working with a Transit AS 2

3 B. Transit AS Tasks C. External Route Propagation D. Internal Route Propagation E. Packet Forwarding in an AS F. Core Router IBGP Requirements in a Transit AS XI. Interacting with IBGP and EBGP in a Transit AS B. AS-Path Processing in IBGP C. Multipath Load Sharing in BGP 1. maximum-paths ibgp D. BGP Split Horizon E. IBGP Full Mesh 1. Example: IBGP Full Mesh F. IBGP Neighbors G. IBGP Next-Hop Processing H. Transit Network Using External Next Hops I. Transit Network Using Edge Routers as Next Hops 1. neighbor next-hop-self 2. Example: Transit Network Using Edge Routers as Next Hops J. Differences Between EBGP and IBGP Sessions 1. Example: Differences Between EBGP and IBGP Sessions K. Summary XII. Forwarding Packets in a Transit AS B. Packet Forwarding in a Transit AS C. Recursive Lookup in Cisco IOS Software D. Routing Protocols in a Transit AS E. BGP and IGP Interaction F. Problems with BGP and IGP Interaction XIII. Configuring a Transit AS B. Configuring IBGP Neighbors 1. neighbor remote-as 2. neighbor description C. Configuring IBGP Sessions Between Loopback Interfaces 1. neighbor update-source D. Configuring BGP Synchronization 1. synchronization E. Changing the Administrative Distance of BGP Routes 1. distance bgp F. Scalability Limitations of IBGP-Based Transit Backbones XIV. Monitoring and Troubleshooting IBGP in a Transit AS B. Monitoring IBGP 1. show ip bgp neighbors 2. show ip bgp 3. Example: Monitoring IBGP C. Common IBGP Problems D. Troubleshooting IBGP Session Startup Issues 3

4 E. Troubleshooting IBGP Route Selection Issues F. Troubleshooting IBGP Synchronization Issues H. Module Summary I. Module Self-Check 1. Module Self-Check Answer Key XV. Route Selection Using Policy Controls XVI. Using Multihomed BGP Networks B. Business Requirements for Multihomed BGP Networks C. Technical Requirements for Multihomed BGP Networks D. BGP Route Selection Without BGP Policies 1. Example: BGP Route Selection Without BGP Policies E. Multihomed Customer Routing Policies F. Influencing BGP Route Selection G. BGP Filters XVII. Employing AS-Path Filters B. AS-Path Filtering Scenarios C. AS-Path Regular Expressions D. String Matching 1. Example: String Matching E. Applying AS-Path Filters F. Configuring BGP AS-Path Filters 1. ip as-path access-list 2. neighbor filter-list G. Monitoring AS-Path Filters 1. show ip bgp regexp 2. show ip bgp filter-list XVIII. Filtering with Prefix-Lists B. Requirements for Prefix-Based Filters C. Prefix-Lists vs. IP Access-Lists D. Configuring Prefix-Lists 1. ip prefix-list 2. Example: Configuring Prefix-Lists E. BGP Filters Implementation F. Implementing Prefix-Lists in the BGP Process 1. neighbor prefix-list 2. distribute-list out 3. Example: Filtering Customer Prefixes 4. Example: Filtering Peer Prefixes G. Modifying Prefix-Lists H. Monitoring Prefix-Lists 1. show ip prefix-list I. Summary XIX. Using Outbound Route Filtering 4

5 B. Outbound Route Filtering 1. Example: Inbound vs. Outbound Filtering C. BGP Prefix-Based Outbound Route Filtering 1. Example: BGP Prefix-Based Outbound Route Filtering D. Outbound Route Filtering Message E. Configuring Outbound Route Filtering 1. neighbor orf prefix-list F. Using Outbound Route Filtering G. Monitoring Outbound Route Filtering XX. Applying Route-Maps as BGP Filters B. Route-Map Overview C. BGP Route-Map Policy List Support 1. ip policy-list 2. match policy-list 3. show ip policy-list 4. Configuring Policy-List Examples 5. Configuring Route-Maps to Reference Policy-List Examples 6. Verifying BGP Route-Map Policy List Support D. BGP Route-Map Continue 1. Route-Map Operation Without Continue Clauses 2. Route-Map Operation With Continue Clauses 3. continue 4. show route-map 5. BGP Route-Map Continue Clause Example Configuration 6. BGP Route-Map Continue Clause Verification Example E. Prefix-List Use in Route-Maps 1. match ip address 2. match ip next-hop 3. match ip route-source F. BGP Filters G. Using Route-Maps as BGP Filters H. Monitoring Route-Maps I. Summary XXI. Implementing Changes in BGP Policy B. Traditional Filtering Limitations C. BGP Soft Reconfiguration 1. Example: Soft Reconfiguration and Memory Use D. Cisco IOS Commands for Soft Reconfiguration 1. neighbor soft-reconfiguration 2. clear ip bgp E. Monitoring Soft Reconfiguration F. BGP Soft Reset Enhancement G. Route Refresh 1. Example: Route Refresh H. Using Route Refresh 1. clear ip bgp I. Monitoring Route Refresh J. Why Use Route-Maps as BGP Filters? K. Summary L. Module Summary M. Module Self-Check 5

6 1. Module Self-Check Answer Key Volume 2 I. Route Selection Using Attributes II. Influencing BGP Route Selection with Weights B. BGP Route Selection Criteria C. Influencing BGP Route Selection D. Configuring Per-Neighbor Weights 1. neighbor weight 2. Example: Configuring Per-Neighbor Weights E. Changing Weights with Route-Maps 1. Example: Changing Weights with Route-Maps F. Monitoring BGP Route Selection and Weights 1. show ip bgp 2. Example: Monitoring BGP Route Selection and Weights G. BGP Route Selection and Filtering Tools Summary III. Setting BGP Local Preference B. Consistent Route Selection Within the AS 1. Example: Consistent Route Selection Within the AS C. BGP Local Preference D. Configuring Default Local Preference 1. Example: Configuring Default Local Preference E. Configuring Local Preference With Route-Maps 1. Example: Configuring Local Preference With Route-Maps F. Monitoring Local Preference 1. Example: Monitoring Local Preference IV. Using AS-Path Prepending B. Return Path Selection in a Multihomed AS C. AS-Path Prepending 1. Example: AS-Path Prepending D. AS-Path Prepending Design Considerations E. Configuring AS-Path Prepending 1. set as-path 2. Example: Configuring AS-Path Prepending F. Monitoring AS-Path Prepending G. AS-Path Filtering Concerns with AS-Path Prepending H. BGP Hide Local-Autonomous System 1. neighbor local-as I. Summary V. Understanding BGP Multi-Exit Discriminators B. Selecting the Proper Return Path C. MED Propagation in a BGP Network D. Changing the Default MED 6

7 1. default-metric (BGP) E. Changing the MED with Route-Maps 1. Example: Changing the MED with Route-Maps F. Advanced MED Configuration 1. Example: Advanced MED Configuration G. Monitoring the MED 1. Example: Monitoring the MED H. Troubleshooting the MED I. Summary VI. Addressing BGP Communities B. Selecting the Proper Return Path C. BGP Communities Overview D. Using Communities 1. Example: Using Communities E. Configuring BGP Communities F. Configuring Route Tagging with BGP Communities 1. Example: Configuring Route Tagging with BGP Communities G. Configuring Community Propagation 1. Example: Configuring Community Propagation H. Defining BGP Named Community-Lists 1. Example: Defining BGP Community-Lists I. BGP Named Community-Lists 1. ip-community-list 2. match community 3. set comm-list delete 4. Named Community List Examples J. BGP Cost Community 1. set extcommunity cost 2. BGP Cost Community Configuration Example K. BGP Link Bandwidth 1. bgp dmzlink-bw 2. neighbor dmzlink-bw 3. Example: BGP Link Bandwidth Configuration 4. Example: BGP Link Bandwidth Configuration L. BGP Support for Sequenced Entries in Extended Community Lists 1. ip extcommunity-list 2. Sequenced Extended Community-List Entry Configuration: Example 3. Resequenced Extended Community-List Entry Configuration: Example 4. Sequenced Extended Community-List Entry Verification: Example M. Matching BGP Communities with Route-Maps 1. Example: Matching BGP Communities with Route-Maps N. Monitoring Communities O. Summary P. Module Summary Q. Module Self-Check 1. Module Self-Check Answer Key VII. Customer-to-Provider Connectivity with BGP VIII. Understanding Customer-to-Provider Connectivity Requirements B. Customer Connectivity Types C. Redundancy in Customer Connections 7

8 D. Customer-to-Provider Routing Schemes E. Customer Routing F. Addressing Requirements 1. Example: Addressing Requirements G. AS Number Allocation IX. Implementing Customer Connectivity Using Static Routing B. Why Use Static Routing C. Characteristics of Static Routing 1. Example: Characteristics of Static Routing D. Designing Static Route Propagation in a Service Provider Network 1. Example: Static Route Propagation E. BGP Backup with Static Routes F. Floating Static Routes with BGP G. Load Sharing with Static Routes 1. Example: Load Sharing with Static Routes X. Connecting a Multihomed Customer to a Single Service Provider B. Configuring BGP on Multihomed Customer Routers 1. Example: Configuring BGP on Multihomed Customers C. Conditional Advertising in Multihomed Customer Networks 1. Example: Conditional Advertising in Multihomed Customer Networks D. Configuring BGP on Service Provider Routes 1. Example: Configuring BGP on Service Provider Routes E. Removing Private AS Numbers 1. neighbor remove-private-as 2. Example: Removing Private AS Numbers F. BGP Support for Dual AS Configuration for Network AS Migrations 1. neighbor local-as 2. Dual-AS Configuration: Example 3. Dual-AS Confederation: Example 4. Replace-AS Configuration: Example G. Backup Solutions with BGP 1. Example: Primary/Backup Link Selection H. Load Sharing with the Multihomed Customer I. Load Sharing with BGP Multipath 1. maximum-paths J. Load Sharing with EBGP Multihop 1. Example: Load Sharing with EBGP Multihop K. Summary XI. Connecting a Multihomed Customer to Multiple Service Providers B. Configuring BGP for Multihomed Customers C. Multihomed Customer Address Space Selection D. Multihomed Customer AS Number Selection E. AS Number Translation F. Primary/Backup Link Selection G. BGP Incoming Link Selection H. Load Sharing with Multiple Providers I. Summary J. Module Summary 8

9 K. Module Self-Check 1. Module Self-Check Answer Key XII. Scaling Service Provider Networks XIII. Scaling IGP and BGP in Service Provider Networks B. Common Service Provider Network C. Route Propagation in Service Provider Networks D. Scaling Service Provider Routing Protocols E. Scaling Service Provider Addressing 1. Example: Scaling Service Provider Addressing F. BGP Policy Accounting 1. bgp-policy 2. set traffic-index 3. Specifying the Match Criteria for BGP Policy Accounting: Example 4. Classifying the IP Traffic and Enabling BGP Policy Accounting: Example XIV. Introducing Route Reflectors B. IBGP Scalability Issues in a Transit AS C. Route Reflectors Split-Horizon Rules D. Redundant Route Reflectors E. Route Reflectors Clusters 1. Example: Route Reflectors Clusters F. Additional Route Reflector Loop-Prevention Mechanisms XV. Designing Networks with Route Reflectors B. Network Design with Route Reflectors 1. Example: Network Design with Route Reflectors C. Potential Network Issues D. Hierarchical Route Reflectors 1. Example: Hierarchical Route Reflectors E. Summary XVI. Configuring and Monitoring Route Reflectors B. Route Reflector Backbone Migration C. Configuring Route Reflectors 1. bgp cluster-id 2. neighbor route-reflector-client 3. Example: Configuring Route Reflectors D. Monitoring Route Reflectors 1. show ip bgp neighbors 2. show ip bgp E. Summary XVII. Introducing Confederations B. IBGP Transit AS Problems 1. Example: IBGP Transit AS Problems C. Splitting a Transit AS with BGP Confederations D. AS-Path Propagation Within the BGP Confederations 9

10 1. Example: AS-Path Propagation Within the BGP Confederation E. AS-Path Processing in BGP Confederations F. Intra-Confederation EBGP Session Properties XVIII. Configuring and Monitoring Confederations B. BGP Confederation Design Rules C. Planning BGP Confederations D. Configuring BGP Confederations 1. router bgp 2. bgp confederation identifier 3. bgp confederation peers 4. Example: Configuring BGP Confederations E. Monitoring BGP Confederations 1. show ip bgp neighbors 2. show ip bgp F. Summary G. Module Summary H. Module Self-Check 1. Module Self-Check Answer Key XIX. Optimizing BGP Scalability XX. Improving BGP Convergence B. BGP Convergence C. BGP Processes D. CPU Effects of BGP Processes 1. Example: CPU Effects of BGP Processes E. Improving BGP Convergence F. PMTU Discovery 1. ip tcp path-mtu-discovery G. Increasing Input Queue Depth 1. hold-queue H. BGP Scan Time 1. bgp scan-time I. BGP Advertisement Interval 1. neighbor advertisement-interval J. BGP Nonstop Forwarding Awareness 1. timers nsf route-hold K. Summary XXI. Limiting the Number of Prefixes Received from a BGP Neighbor B. Limiting the Number of Routes Received from a Neighbor C. Configuring the BGP Maximum-Prefix Function 1. neighbor maximum-prefix D. Monitoring the BGP Maximum-Prefix Function 1. Example: Monitoring the BGP E. Summary XXII. Implementing BGP Peer Groups B. Peer Group Requirements 10

11 1. Example: Peer Group Requirements-Customer Connections 2. Example: Peer Group Requirements-BGP Route Reflectors 3. Example: Peer Group Requirements-Edge Router at a Peering Point C. Peer Groups as a BGP Performance Tool D. BGP Peer Group Limitations E. BGP Peer Groups in Cisco IOS Software F. BGP Dynamic Update Peer-Groups Feature 1. clear ip bgp update-group 2. debug ip bgp groups 3. show ip bgp replication 4. show ip bgp update-group G. BGP Configuration Using Peer Templates 1. Peer Session Commands 2. template peer-session 3. inherit peer-session 4. neighbor inherit peer-session 5. show ip bgp template peer-session 6. Peer Policy Commands 7. inherit peer-policy 8. neighbor inherit peer-policy 9. show ip bgp template peer-policy H. Configuring Peer Groups 1. neighbor peer-group(creating) 2. neighbor peer-group(assigning Members) 3. Example: BGP Peer Group-Customer Connections 4. Example: BGP Peer Group-BGP Route Reflector 5. Example: BGP Peer Group-Edge Router at a Peering Point I. Monitoring Peer Groups 1. show ip bgp peer-group 2. clear ip bgp J. Summary XXIII. Using BGP Route Dampening B. BGP Route Dampening C. Route-Dampening Operation D. Configuring BGP Route Dampening E. Releasing Dampened Routes 1. clear ip bgp flap-statistics 2. clear ip bgp dampening F. Monitoring Route Dampening 1. Example: Monitoring Route Dampening H. Module Summary I. Module Self-Check 1. Module Self-Check Answer Key Lab Guide Overview/Outline Lab 1-1: Initial Lab Setup Lab 1-2: Configuration Basic BGP Lab 2-1: Configuring a Transit AS Lab 3-1: Using Multihomed BGP Networks 11

12 Lab 3-2: Employing AS-Path Filters Lab 3-3: Filtering with Prefix-Lists Lab 3-4: Implementing Changes in BGP Policy Lab 4-1: Influencing BGP Route Selection with Weights Lab 4-2: Setting BGP Local Preference Lab 4-3: Understanding BGP Multi-Exit Discriminators Lab 4-4: Addressing BGP Communities Lab 6-1: Introducing Route Reflectors Lab 6-2: Configuring and Monitoring Confederations Lab 7-1: Limiting the Number of Prefixes Received from a BGP Neighbor Lab 7-2: Implementing BGP Peer Groups Lab 7-3: Using BGP Route Dampening Answer Key 12