Cisco Systems 78-11741-02 CONTENTS

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Cisco IOS IP Configuration Guide

CONTENTS

About Cisco IOS Software Documentation xxix

Documentation Objectives xxix

Audience xxix

Documentation Organization xxix

Documentation Modules xxix

Master Indexes xxxii

Supporting Documents and Resources xxxii

New and Changed Information xxxiii

Document Conventions xxxiii

Obtaining Documentation xxxv

World Wide Web xxxv

Documentation CD-ROM xxxv

Ordering Documentation xxxv

Documentation Feedback xxxv

Obtaining Technical Assistance xxxvi

Cisco.com xxxvi

Technical Assistance Center xxxvi

Contacting TAC by Using the Cisco TAC Website xxxvi

Contacting TAC by Telephone xxxvii

Using Cisco IOS Software xxxix

Understanding Command Modes xxxix

Getting Help xl

Example: How to Find Command Options xli

Using the no and default Forms of Commands xliii

Saving Configuration Changes xliv

Filtering Output from the show and more Commands xliv

Identifying Supported Platforms xlv

Using Feature Navigator xlv

Using Software Release Notes xlv

IP Overview IPC-1

IP Addressing and Services IPC-1

IP Routing Protocols IPC-2

Contents

Main Page CONTENTS Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page About Cisco IOS Software Documentation Documentation Objectives Audience Documentation Organization Documentation Modules xxx Figure 1 shows the Cisco IOS software documentation modules. P3R P2R IR xxxi XC VR QR XR Master Indexes Supporting Documents and Resources New and Changed Information Document Conventions Page Obtaining Documentation World Wide Web Documentation CD-ROM Ordering Documentation Documentation Feedback Obtaining Technical Assistance Cisco.com Technical Assistance Center Contacting TAC by Using the Cisco TAC Website Contacting TAC by Telephone Page Using Cisco IOS Software Understanding Command Modes Getting Help Example: How to Find Command Options Page Using the no and default Forms of Commands Saving Configuration Changes Filtering Output from the show and more Commands Identifying Supported Platforms Using Feature Navigator Using Software Release Notes Page IP Overview IP Addressing and Services IP Routing Protocols Determining a Routing Process Interior and Exterior Gateway Protocols Interior Gateway Protocols Exterior Gateway Protocols Multiple Routing Protocols IP Multicast Page Page Configuring IP Addressing IP Addressing Task List Assigning IP Addresses to Network Interfaces Page Assigning Multiple IP Addresses to Network Interfaces Enabling Use of Subnet Zero Disabling Classless Routing Behavior Enabling IP Processing on a Serial Interface Configuring Address Resolution Methods Establishing Address Resolution Defining a Static ARP Cache Setting ARP Encapsulations Enabling Proxy ARP Configuring Local-Area Mobility Mapping Host Names to IP Addresses Assigning Host Names to IP Addresses Specifying the Domain Name Specifying a Name Server Enabling the DNS Using the DNS to Discover ISO CLNS Addresses Configuring HP Probe Proxy Name Requests Configuring the Next Hop Resolution Protocol The Cisco Implementation of NHRP Page Protocol Operation NHRP Configuration Task List Enabling NHRP on an Interface Configuring a Static IP-to-NBMA Address Mapping for a Station Statically Configuring a Next Hop Server Configuring NHRP Authentication Controlling the Triggering of NHRP Triggering NHRP by IP Packets Triggering NHRP on a per-Destination Basis Triggering NHRP Based on Traffic Thresholds Restrictions Prerequisites NHRP Configuration Task List Changing the Rate for Triggering SVCs Applying the Rates to Specific Destinations Controlling the NHRP Packet Rate Suppressing Forward and Reverse Record Options Specifying the NHRP Responder Address Changing the Time Period NBMA Addresses Are Advertised as Valid Configuring a GRE Tunnel for Multipoint Operation Configuring NHRP Server-Only Mode Enabling IP Routing Routing Assistance When IP Routing Is Disabled Proxy ARP Default Gateway ICMP Router Discovery Protocol Enabling IRDP Processing Changing IRDP Parameters Enabling IP Bridging Enabling Integrated Routing and Bridging Configuring a Routing Process Configuring Broadcast Packet Handling Enabling Directed Broadcast-to-Physical Broadcast Translation Forwarding UDP Broadcast Packets and Protocols Establishing an IP Broadcast Address Flooding IP Broadcasts Speeding Up Flooding of UDP Datagrams Configuring Network Address Translation NAT Applications Benefits NAT Terminology NAT Configuration Task List Translating Inside Source Addresses Configuring Static Translation Configuring Dynamic Translation with an Access List Configuring Dynamic Translation with a Route Map Overloading an Inside Global Address Inside NAT table Translating Overlapping Addresses Page Configuring Static Translation Configuring Dynamic Translation Providing TCP Load Distribution NAT table Inside 1.1.1.1 1.1.1.2 1.1.1.3 1.1.1.127 Changing Translation Timeouts Monitoring and Maintaining NAT Deploying NAT Between an IP Phone and Cisco CallManager Monitoring and Maintaining IP Addressing Specifying the Format of Network Masks Page Monitoring and Maintaining NHRP IP Addressing Examples Creating a Network from Separated Subnets Example Serial Interfaces Configuration Example IP Domains Example Dynamic Lookup Example HP Hosts on a Network Segment Example Logical NBMA Example IPC-52 Figure9 Two Logical NBMA Networks over One Physical NBMA Network NHRP over ATM Example IPC-54 The significant portions of the configurations for routers A, B, and C follow: IPC-55 Changing the Rate for Triggering SVCs Example IPC-56 IPC-57 Applying NHRP Rates to Specific Destinations Example NHRP on a Multipoint Tunnel Example Broadcasting Examples Flooded Broadcast Example Flooding of IP Broadcasts Example Helper Addresses Example IPC-61 Figure13 IP Helper Addresses The following example shows the configuration: NAT Configuration Examples The following sections show NAT configuration examples. Dynamic Inside Source Translation Example The following example translates all source addresses using a route map. IPC-62 Overloading Inside Global Addresses Example Translating Overlapping Address Example IPC-63 TCP Load Distribution Example ping Command Example Page Configuring DHCP DHCP Server Overview Page DHCP Client Overview DHCP Relay Agent Overview DHCP Configuration Task List Enabling the Cisco IOS DHCP Server and Relay Agent Features Configuring a DHCP Database Agent or Disabling DHCP Conflict Logging Excluding IP Addresses Configuring a DHCP Address Pool Configuring the DHCP Address Pool Name and Entering DHCP Pool Configuration Mode Configuring the DHCP Address Pool Subnet and Mask Configuring the Domain Name for the Client Configuring the IP Domain Name System Servers for the Client Configuring the NetBIOS Windows Internet Naming Service Servers for the Client Configuring the NetBIOS Node Type for the Client Configuring Manual Bindings Page Configuring a DHCP Server Boot File Configuring the Number of Ping Packets Configuring the Timeout Value for Ping Packets Enabling the Cisco IOS DHCP Client on Ethernet Interfaces Configuring DHCP Server Options Import and Autoconfiguration Configuring the Relay Agent Information Option in BOOTREPLY Messages Configuring a Relay Agent Information Reforwarding Policy Enabling the DHCP Smart-Relay Feature Monitoring and Maintaining the DHCP Server Configuration Examples DHCP Database Agent Configuration Example DHCP Address Pool Configuration Example Manual Bindings Configuration Example Cisco IOS DHCP Client Example IPC-79 DHCP Server Options Import and Autoconfiguration Example Figure16 DHCP Example Network Topology Central Router Remote Router Local DNS server Central router Remote router Page Configuring IP Services IP Services Task List Managing IP Connections Enabling ICMP Protocol Unreachable Messages Enabling ICMP Redirect Messages Enabling ICMP Mask Reply Messages Understanding Path MTU Discovery Setting the MTU Packet Size Enabling IP Source Routing Configuring Simplex Ethernet Interfaces Configuring a DRP Server Agent Enabling the DRP Server Agent Limiting the Source of DRP Queries Configuring Authentication of DRP Queries and Responses Filtering IP Packets Using Access Lists Creating Standard and Extended Access Lists Using Numbers Page Page Creating Standard and Extended Access Lists Using Names Page Specifying IP Extended Access Lists with Fragment Control Page Benefits of Fragment Control in an IP Extended Access List Enabling Turbo Access Control Lists Configuring Turbo ACLs Verifying Turbo ACLs Applying Time Ranges to Access Lists Including Comments About Entries in Access Lists Applying Access Lists Controlling Access to a Line or Interface Controlling Policy Routing and the Filtering of Routing Information Controlling Dialer Functions Configuring the Hot Standby Router Protocol Enabling HSRP Configuring HSRP Group Attributes Changing the HSRP MAC Refresh Interval Enabling HSRP MIB Traps Enabling HSRP Support for MPLS VPNs Defining VPNs Enabling HSRP Verifying HSRP Support for MPLS VPNs Enabling HSRP Support for ICMP Redirect Messages Redirects to Active HSRP Routers Page Redirects to Passive HSRP Routers Redirects to Non-HSRP Routers Passive HSRP Router Advertisements Redirects Not Sent Configuring HSRP Support for ICMP Redirect Messages Configuring IP Accounting Configuring IP MAC Accounting Configuring IP Precedence Accounting Configuring TCP Performance Parameters Compressing TCP Packet Headers Expressing TCP Header Compression Changing the Number of TCP Header Compression Connections Setting the TCP Connection Attempt Time Enabling TCP Path MTU Discovery Enabling TCP Selective Acknowledgment Enabling TCP Time Stamp Setting the TCP Maximum Read Size Setting the TCP Window Size Setting the TCP Outgoing Queue Size Configuring IP over WANs Configuring the MultiNode Load Balancing Forwarding Agent MNLB Forwarding Agent Configuration Task List Enabling CEF Enabling NetFlow Switching Enabling IP Multicast Routing Configuring the Router as a Forwarding Agent Monitoring and Maintaining the IP Network Monitoring and Maintaining the DRP Server Agent Clearing the Access List Counters Monitoring the MNLB Forwarding Agent Monitoring and Maintaining HSRP Support for ICMP Redirect Messages IP Services Configuration Examples ICMP Services Example Simplex Ethernet Interfaces Example DRP Server Agent Example Numbered Access List Examples Turbo Access Control List Example Implicit Masks in Access Lists Examples Extended Access List Examples Named Access List Example IP Extended Access List with Fragment Control Example Time Range Applied to an IP Access List Example Commented IP Access List Entry Examples IP Accounting Example HSRP Load Sharing Example HSRP MAC Refresh Interval Examples No Switch or Learning Bridge Present Example Switch or Learning Bridge Present Example IPC-128 HSRP MIB Trap Example Primary Router Configuration Backup Router Configuration HSRP Support for MPLS VPNs Example IPC-129 HSRP Support for ICMP Redirect Messages Example Router A ConfigurationActive for Group 1 and Standby for Group 2 Router B ConfigurationStandby for Group 1 and Active for Group 2 IPC-130 MNLB Forwarding Agent Examples This section provides the following configuration examples: The network configured is shown in Figure 22. Forwarding Agent Configuration for FA2 Example IPC-131 Services Manager Configuration for SM Example IPC-132 Configuring Server Load Balancing IOS SLB Functions and Capabilities Algorithms for Server Load Balancing Weighted Round Robin Weighted Least Connections Port-Bound Servers Client-Assigned Load Balancing Content Flow Monitor Support Sticky Connections Maximum Connections Delayed Removal of TCP Connection Context TCP Session Reassignment Automatic Server Failure Detection Automatic Unfail Slow Start Dynamic Feedback Protocol for IOS SLB Alternate IP Addresses Transparent Web Cache Balancing NAT Redundancy EnhancementStateless Backup Restrictions IOS SLB Configuration Task List Specifying a Server Farm Specifying a Load-Balancing Algorithm Specifying a Bind ID Specifying a Real Server Configuring Real Server Attributes Enabling the Real Server for Service Specifying a Virtual Server Associating a Virtual Server with a Server Farm Configuring Virtual Server Attributes Adjusting Virtual Server Values Preventing Advertisement of Virtual Server Address Enabling the Virtual Server for Service Configuring IOS SLB Dynamic Feedback Protocol Configuring NAT Implementing IOS SLB Stateless Backup How IOS SLB Stateless Backup Works Configuring IOS SLB Stateless Backup Enabling HSRP Customizing Group Attributes Verifying the IOS SLB Stateless Backup Configuration Verifying IOS SLB Verifying IOS SLB Installation Verifying Server Failure Detection Troubleshooting IOS SLB Monitoring and Maintaining IOS SLB Configuration Examples IPC-152 IOS SLB Network Configuration Example This section provides a configuration example based on the network layout shown in Figure24. IPC-153 NAT Configuration Example This section provides a configuration example based on the network layout shown in Figure 25. The topology in Figure25 has four Web servers, configured as follows: IPC-154 Server 4 has multiple HTTP server applications listening on ports 8080, 8081, and 8082. The configuration statements for Switch B are as follows: The configuration statements for Switch C are as follows: HSRP Configuration Example IPC-156 The configuration for Device A is as follows: The configuration for Device B is as follows: IOS SLB Stateless Backup Configuration Example Page Configuring Mobile IP Mobile IP Overview Why is Mobile IP Needed? Mobile IP Components How Mobile IP Works Agent Discovery Registration Routing Mobile IP Security MN-HA MN-FA FA-HA HA-HA Storing Security Associations Storing SAs on AAA Caching SAs on HA Home Agent Redundancy HSRP Groups How HA Redundancy Works Managing Mobility Binding Tables Prerequisites Mobile IP Configuration Task List Enabling Home Agent Services Enabling Foreign Agent Services Configuring AAA in the Mobile IP Environment Configuring RADIUS in the Mobile IP Environment Configuring TACACS+ in the Mobile IP Environment Verifying Setup Monitoring and Maintaining Mobile IP Shutting Down Mobile IP Mobile IP HA Redundancy Configuration Task List Enabling Mobile IP Enabling HSRP Configuring HSRP Group Attributes Enabling HA Redundancy for a Physical Network Enabling HA Redundancy for a Virtual Network Using One Physical Network Enabling HA Redundancy for a Virtual Network Using Multiple Physical Networks Enabling HA Redundancy for Multiple Virtual Networks Using One Physical Network Enabling HA Redundancy for Multiple Virtual Networks Using Multiple Physical Networks Verifying HA Redundancy Monitoring and Maintaining HA Redundancy Mobile IP Configuration Examples Home Agent Configuration Example IPC-177 Home Agent Using AAA Server Example Foreign Agent Configuration Example Mobile IP HA Redundancy Configuration Examples Page HA Redundancy for Physical Networks Example Page HA Redundancy for a Virtual Network Using One Physical Network Example HA Redundancy for a Virtual Network Using Multiple Physical Networks Example Page IPC-185 HA Redundancy for Multiple Virtual Networks Using One Physical Network Example IPC-187 IPC-188 HA Redundancy for Multiple Virtual Networks Using Multiple Physical Networks Example IPC-190 IPC-191 IPC-192 Page Page Configuring On-Demand Routing On-Demand Routing Configuration Task List Enabling ODR Filtering ODR Information Redistributing ODR Information into the Dynamic Routing Protocol of the Hub Reconfiguring CDP or ODR Timers Using ODR with Dialer Mappings Configuring Routing Information Protocol RIP Configuration Task List Enabling RIP Allowing Unicast Updates for RIP Adjusting Timers Specifying a RIP Version Enabling RIP Authentication RIP Route Summarization Page Restrictions to RIP Route Summarization Configuring Route Summarization on an Interface Verifying IP Route Summarization Disabling Automatic Route Summarization Running IGRP and RIP Concurrently Disabling the Validation of Source IP Addresses Enabling or Disabling Split Horizon Configuring Interpacket Delay Connecting RIP to a WAN RIP Configuration Examples Route Summarization Examples Example 1: Correct Configuration Example 2: Incorrect Configuration Split Horizon Examples Example 1 Example 2 IPC-211 Figure35 Disabled Split Horizon Example for Frame Relay Network Configuration for Router A Configuration for Router B Configuration for Router C Address Family Timers Example Configuring IGRP The Cisco IGRP Implementation IGRP Updates IGRP Configuration Task List Creating the IGRP Routing Process Allowing Unicast Updates for IGRP Defining Unequal-Cost Load Balancing Controlling Traffic Distribution Adjusting the IGRP Metric Weights Adjusting Timers Disabling Holddown Enforcing a Maximum Network Diameter Validating Source IP Addresses Enabling or Disabling Split Horizon IGRP Configuration Examples IGRP Feasible Successor Relationship Example Split Horizon Examples IPC-221 Figure38 Disabled Split Horizon Example Router Configuration A Router Configuration B Router Configuration C Page Configuring OSPF The Cisco OSPF Implementation OSPF Configuration Task List Enabling OSPF Configuring OSPF Interface Parameters Configuring OSPF over Different Physical Networks Configuring Your OSPF Network Type Configuring Point-to-Multipoint, Broadcast Networks Configuring OSPF for Nonbroadcast Networks Configuring OSPF Area Parameters Configuring OSPF NSSA Implementation Considerations Configuring Route Summarization Between OSPF Areas Configuring Route Summarization When Redistributing Routes into OSPF Creating Virtual Links Generating a Default Route Configuring Lookup of DNS Names Forcing the Router ID Choice with a Loopback Interface Controlling Default Metrics Changing the OSPF Administrative Distances Configuring OSPF on Simplex Ethernet Interfaces Configuring Route Calculation Timers Configuring OSPF over On-Demand Circuits Implementation Considerations Logging Neighbors Going Up or Down Changing the LSA Group Pacing Original LSA Behavior LSA Group Pacing With Multiple Timers Blocking OSPF LSA Flooding Reducing LSA Flooding Ignoring MOSPF LSA Packets Displaying OSPF Update Packet Pacing Monitoring and Maintaining OSPF OSPF Configuration Examples OSPF Point-to-Multipoint Example IPC-242 Figure41 OSPF Point-to-Multipoint Example Mollie Configuration Neon Configuration Platty Configuration OSPF Point-to-Multipoint, Broadcast Example The following example illustrates a point-to-multipoint network with broadcast: The following example shows the configuration of the neighbor at 10.0.1.3: The output shown for neighbors in the first configuration is as follows: The route information in the first configuration is as follows: OSPF Point-to-Multipoint, Nonbroadcast Example The following example illustrates a point-to-multipoint network with nonbroadcast: The following example is the configuration for the router on the other side: The output shown for neighbors in the first configuration is as follows: Variable-Length Subnet Masks Example OSPF Routing and Route Redistribution Examples Basic OSPF Configuration Examples Basic OSPF Configuration Example for Internal Router, ABR, and ASBRs Complex Internal Router, ABR, and ASBRs Example IPC-247 Figure42 Sample OSPF Autonomous System Network Map are advertised by OSPF. In this configuration, five routers are configured with OSPF: to S0. IPC-248 Note It is not necessary to include definitions of all areas in an OSPF autonomous system in the Router A ConfigurationInternal Router Router B ConfigurationInternal Router Router C ConfigurationABR Complex OSPF Configuration for ABR Examples IPC-250 In the following configuration OSPF is on network 131.119.0.0: In the following configuration IGRP autonomous system 200 is on 131.119.0.0: Route Map Examples Page Changing OSPF Administrative Distance Example IPC-253 OSPF over On-Demand Routing Example IPC-254 Figure45 OSPF over On-Demand Circuit Token Ring 0 BRI 0 BRI 0 Ethernet 0 Router A Router B LSA Group Pacing Example Block LSA Flooding Example Ignore MOSPF LSA Packets Example Page Configuring EIGRP The Cisco EIGRP Implementation Page EIGRP Configuration Task List Enabling EIGRP Making the Transition from IGRP to EIGRP Logging EIGRP Neighbor Adjacency Changes Configuring the Percentage of Link Bandwidth Used Adjusting the EIGRP Metric Weights Mismatched K Values The Goodbye Message Disabling Route Summarization Configuring Summary Aggregate Addresses Configuring Floating Summary Routes . . . . . . . . Configuring EIGRP Route Authentication . . . . Configuring EIGRP Protocol-Independent Parameters Adjusting the Interval Between Hello Packets and the Hold Time Disabling Split Horizon Configuring EIGRP Stub Routing Dual-Homed Remote Topology Page Page EIGRP Stub Routing Configuration Task List Configuring EIGRP Stub Routing Verifying EIGRP Stub Routing Monitoring and Maintaining EIGRP EIGRP Configuration Examples Route Summarization Example Page IPC-275 Route Authentication Example Figure52 EIGRP Route Authentication Scenario Enhanced IGRP Autonomous System 1 Router A Router B Stub Routing Example Configuring Integrated IS-IS IS-IS Configuration Task List Enabling IS-IS and Assigning Areas Page Enabling IP Routing for an Area on an Interface IS-IS Interface Parameters Configuration Task List Configuring IS-IS Link-State Metrics Setting the Advertised Hello Interval Setting the Advertised CSNP Interval Setting the Retransmission Interval Setting the LSP Transmissions Interval Setting the Retransmission Throttle Interval Setting the Hello Multiplier Specifying Designated Router Election Specifying the Interface Circuit Type Assigning a Password for an Interface Limiting LSP Flooding Blocking Flooding on Specific Interfaces Configuring Mesh Groups Miscellaneous IS-IS Parameters Configuration Task List Generating a Default Route Specifying the System Type Configuring IS-IS Authentication Passwords Summarizing Address Ranges Setting the Overload Bit Changing the Routing Level for an Area Tuning LSP Interval and Lifetime Customizing IS-IS Throttling of LSP Generation, SPF Calculation, and PRC Partial Route Computation (PRC) Benefits of Throttling IS-IS LSP Generation, SPF Calculation, and PRC How Throttling of IS-IS LSP Generation, SPF Calculation, and PRC Works Modifying the Output of show Commands Monitoring IS-IS IS-IS Configuration Examples Enabling IS-IS Configuration Example IPC-290 Figure53 IS-IS Routing Multiarea IS-IS Configuration for CLNS Network Example Router A Router B Router C E0 E0 S0 IPC-291 IS-IS Throttle Timers Example Page Configuring BGP The Cisco BGP Implementation How BGP Selects Paths BGP Multipath Support Basic BGP Configuration Task List Advanced BGP Configuration Task List Configuring Basic BGP Features Enabling BGP Routing Configuring BGP Neighbors Managing Routing Policy Changes Resetting a Router Using BGP Dynamic Inbound Soft Reset Resetting a Router Using BGP Outbound Soft Reset Configuring BGP Soft Reset Using Stored Routing Policy Information IPC-301 Verifying BGP Soft Reset shows that the peer supports the route refresh capability: Step 2 Enter the show ip bgp neighbors EXEC command to display information about the BGP and TCP connections to neighbors: Configuring BGP Interactions with IGPs Configuring BGP Weights Disabling Autonomous System Path Comparison Configuring BGP Route Filtering by Neighbor Configuring BGP Filtering Using Prefix Lists How the System Filters Traffic by Prefix List Creating a Prefix List Configuring a Prefix List Entry Configuring How Sequence Numbers of Prefix List Entries Are Specified Deleting a Prefix List or Prefix List Entries Displaying Prefix Entries Clearing the Hit Count Table of Prefix List Entries Configuring BGP Path Filtering by Neighbor Disabling Next Hop Processing on BGP Updates Disabling Next Hop Processing Using a Specific Address Disabling Next Hop Processing Using a Route Map Configuring BGP Next Hop Propagation Configuring the BGP Version Configuring the MED Metric Configuring Advanced BGP Features Using Route Maps to Modify Updates Resetting eBGP Connections Immediately upon Link Failure Configuring Aggregate Addresses Disabling Automatic Summarization of Network Numbers Configuring BGP Community Filtering Page Specifying the Format for the Community Configuring BGP Conditional Advertisement BGP Conditional Advertisement Configuration Task List Conditional Advertisement of a Set of Routes Verifying BGP Conditional Advertisement BGP Conditional Advertisement Troubleshooting Tips Configuring a Routing Domain Confederation Configuring a Route Reflector IPC-318 Figure56 Simple BGP Model with a Route Reflector Router B Figure57 More Complex BGP Route Reflector Model Router A Page Configuring BGP Peer Groups Creating the Peer Group Assigning Options to the Peer Group Page Configuring MD5 Authentication for BGP Peering Sessions BGP through PIX Firewalls Making Neighbors Members of the Peer Group Disabling a Peer or Peer Group Indicating Backdoor Routes Modifying Parameters While Updating the IP Routing Table Setting Administrative Distance Adjusting BGP Timers Changing the Default Local Preference Value Redistributing Network 0.0.0.0 Configuring the Router to Consider a Missing MED as Worst Path Selecting Path Based on MEDs from Other Autonomous Systems Configuring the Router to Use the MED to Choose a Path from Subautonomous System Paths Configuring the Router to Use the MED to Choose a Path in a Confederation Configuring Route Dampening Minimizing Flapping Understanding Route Dampening Terms Enabling Route Dampening Monitoring and Maintaining BGP Route Dampening Monitoring and Maintaining BGP Logging Changes in Neighbor Status BGP Configuration Examples BGP Route Map Examples Page Page BGP Neighbor Configuration Examples BGP Prefix List Filtering Examples Route Filtering Configuration Example Using a Single Prefix List Route Filtering Configuration Example Specifying a Group of Prefixes Added or Deleted Prefix List Entries Examples BGP Soft Reset Examples Dynamic Inbound Soft Reset Example Inbound Soft Reset Using Stored Information Example BGP Synchronization Examples BGP Path Filtering by Neighbor Examples BGP Aggregate Route Examples BGP Community with Route Maps Examples Page BGP Conditional Advertisement Configuration Examples BGP Confederation Examples BGP Peer Group Examples iBGP Peer Group Example eBGP Peer Group Example TCP MD5 Authentication for BGP Examples Configuring Multiprotocol BGP Extensions for IP Multicast Page Multiprotocol BGP Configuration Task List Understanding NLRI Keywords and Address Families Configuring a Multiprotocol BGP Peer Configuring a Multiprotocol BGP Peer Group Advertising Routes into Multiprotocol BGP Configuring Route Maps for Multiprotocol BGP Prefixes Redistributing Prefixes into Multiprotocol BGP Configuring DVMRP Interoperability with Multiprotocol BGP Redistributing Multiprotocol BGP Routes into DVMRP Redistributing DVMRP Routes into Multiprotocol BGP Configuring a Multiprotocol BGP Route Reflector Configuring Aggregate Multiprotocol BGP Addresses Verifying Multiprotocol BGP Configuration and Operation IPC-358 Step 2 Enter the show ip bgp ipv4 multicast summary EXEC command to display a summary of multicast This section provides the following multiprotocol BGP configuration examples: database information: Multiprotocol BGP Configuration Examples Multiprotocol BGP Peer Examples Multiprotocol BGP Peer Group Examples Multiprotocol BGP Network Advertisement Examples Multiprotocol BGP Route Map Examples Multiprotocol BGP Route Redistribute Examples Multiprotocol BGP Route Reflector Examples Aggregate Multiprotocol BGP Address Examples Page Configuring IP Routing Protocol-Independent Features Protocol-Independent Feature Task List Using Variable-Length Subnet Masks Configuring Static Routes Specifying Default Routes Specifying a Default Network Understanding Gateway of Last Resort Changing the Maximum Number of Paths Configuring Multi-Interface Load Splitting Redistributing Routing Information Page Understanding Supported Metric Translations Filtering Routing Information Preventing Routing Updates Through an Interface Configuring Default Passive Interfaces Controlling the Advertising of Routes in Routing Updates Controlling the Processing of Routing Updates Filtering Sources of Routing Information Enabling Policy Routing (PBR) Page Preverifying Next-Hop Availability Displaying Route-Map Policy Information Enabling Fast-Switched Policy Routing Enabling Local Policy Routing Managing Authentication Keys Monitoring and Maintaining the IP Network Clearing Routes from the IP Routing Table IP Routing Protocol-Independent Configuration Examples Variable-Length Subnet Mask Example Overriding Static Routes with Dynamic Protocols Example Administrative Distance Examples Static Routing Redistribution Example IGRP Redistribution Example RIP and IGRP Redistribution Example EIGRP Redistribution Examples RIP and EIGRP Redistribution Examples Simple Redistribution Example Complex Redistribution Example OSPF Routing and Route Redistribution Examples Basic OSPF Configuration Examples Internal Router, ABR, and ASBRs Configuration Example IPC-386 Figure63 Example OSPF Autonomous System Network Map are advertised by OSPF. In this configuration, five routers are configured in OSPF autonomous system 1: to S0. IPC-387 Router A ConfigurationInternal Router Router B ConfigurationInternal Router Router C ConfigurationABR Router D ConfigurationInternal Router Complex OSPF Configuration Example IPC-389 In the following configuration, OSPF is on network 172.19.0.0: In the following configuration IGRP autonomous system 1 is on 172.19.0.0: Default Metric Values Redistribution Example Policy Routing (Route Map) Examples IPC-391 Passive Interface Examples Default Passive Interface Example Policy Routing Example IPC-394 Key Management Examples The following example configures a key chain named trees: IPC-395 Page Page Page Configuring IP Multicast Routing The Cisco IP Multicast Routing Implementation IGMP IGMP Versions PIM CGMP Basic IP Multicast Routing Configuration Task List Advanced IP Multicast Routing Configuration Task List Enabling IP Multicast Routing Enabling PIM on an Interface Enabling Dense Mode Enabling Sparse Mode Enabling Sparse-Dense Mode Configuring PIM Dense Mode State Refresh Configuring a Rendezvous Point Configuring Auto-RP Setting Up Auto-RP in a New Internetwork Adding Auto-RP to an Existing Sparse Mode Cloud Choosing a Default RP Announcing the RP and the Group Range It Serves Assigning the RP Mapping Agent Filtering Incoming RP Announcement Messages IGMP Features Configuration Task List Configuring a Router to Be a Member of a Group Controlling Access to IP Multicast Groups Changing the IGMP Version Modifying the IGMP Host-Query Message and Query Timeout Intervals Routers That Run IGMP Version 1 Routers That Run IGMP Version 2 Configuring IGMP Version 3 Restrictions Traffic Filtering with Multicast Groups That Are Not Configured in SSM Mode Interoperability with IGMP Snooping Interoperability with CGMP Changing the IGMP Query Timeout Changing the Maximum Query Response Time Configuring the Router as a Statically Connected Member Configuring IGMP Leave Latency Configuring the TTL Threshold Disabling Fast Switching of IP Multicast SAP Listener Support Configuration Task List Enabling SAP Listener Support Limiting How Long a SAP Cache Entry Exists Enabling the Functional Address for IP Multicast over Token Ring LANs Configuring PIM Version 2 PIM Version 2 Configuration Task List Specifying the PIM Version Configuring PIM Version 2 Only Configuring PIM Sparse-Dense Mode Defining a PIM Sparse Mode Domain Border Interface Configuring Candidate BSRs Configuring Candidate RPs Making the Transition to PIM Version 2 Deciding When to Configure a BSR Dense Mode Sparse Mode Monitoring the RP Mapping Information Advanced PIM Features Configuration Task List Understanding PIM Shared Tree and Source Tree (Shortest-Path Tree) Understanding Reverse Path Forwarding Delaying the Use of PIM Shortest-Path Tree Assigning an RP to Multicast Groups Increasing Control over RPs Modifying the PIM Router Query Message Interval Understanding the PIM Registering Process PIM Version 1 Compatibility Limiting the Rate of PIM Register Messages Configuring the IP Source Address of Register Messages Enabling Proxy Registering Enabling PIM Nonbroadcast Multiaccess Mode Configuring an IP Multicast Static Route Controlling the Transmission Rate to a Multicast Group Configuring RTP Header Compression Page Enabling RTP Header Compression on a Serial Interface Enabling RTP Header Compression with Frame Relay Encapsulation Changing the Number of Header Compression Connections Enabling Express RTP Header Compression Configuring IP Multicast over ATM Point-to-Multipoint Virtual Circuits Page Enabling IP Multicast over ATM Point-to-Multipoint VCs Limiting the Number of VCs Idling Policy How the Idling Policy Works Keeping VCs from Idling Configuring an IP Multicast Boundary Configuring an Intermediate IP Multicast Helper Storing IP Multicast Headers Enabling CGMP Configuring Stub IP Multicast Routing Load Splitting IP Multicast Traffic Across Equal-Cost Paths Configuration Task List Enabling Native Load Splitting Enabling Load Splitting Across Tunnels Configuring the Access Router Configuring the Router at the Opposite End of the Tunnel Configuring Both Routers to RPF Load Splitting to a Stub Network Load Splitting to the Middle of a Network Verifying the Load Splitting Monitoring and Maintaining IP Multicast Routing Configuration Task List Page Using IP Multicast Heartbeat IP Multicast Configuration Examples PIM Dense Mode Example PIM Sparse Mode Example PIM Dense Mode State Refresh Example Functional Address for IP Multicast over Token Ring LAN Example PIM Version 2 Examples BSR Configuration Example Border Router Configuration Example RFC 2362 Interoperable Candidate RP Example RTP Header Compression Examples IPC-452 Express RTP Header Compression with PPP Encapsulation Example IPC-453 Express RTP Header Compression with Frame Relay Encapsulation Example IPC-454 IP Multicast over ATM Point-to-Multipoint VC Example The following example shows how to enable IP multicast over ATM point-to-multipoint VCs: Administratively Scoped Boundary Example IP Multicast Helper Example IPC-456 The configurations for Router A and Router C are as follows: Router AFirst Hop Router Configuration Stub IP Multicast Example The configurations for Router A and Router B are as follows: IPC-457 Load Splitting IP Multicast Traffic Across Equal-Cost Paths Example E0/5 E0 Figure75 IP Multicast Load Splitting Across Equal-Cost Paths Router A Router B Source S1 IP Multicast Heartbeat Example Configuring Source Specific Multicast SSM Components Overview How SSM Differs from Internet Standard Multicast SSM IP Address Range SSM Operations IGMPv3 Host Signalling IGMP v3lite Host Signalling URD Host Signalling Page Benefits IP Multicast Address Management Not Required Denial of Service Attacks from Unwanted Sources Inhibited Easy to Install and Manage Ideal for Internet Broadcast Applications Restrictions Legacy Applications Within the SSM Range Restrictions IGMP v3lite and URD Require a Cisco IOS Last Hop Router Address Management Restrictions IGMP Snooping and CGMP Limitations URD Intercept URL Limitations State Maintenance Limitations HSIL Limitations SSM Configuration Task List Configuring SSM Monitoring SSM SSM Configuration Examples SSM with IGMPv3 Example SSM with IGMP v3lite and URD Example SSM Filtering Example IPC-469 Page Configuring Bidirectional PIM Bidir-PIM Overview Page DF Election Bidirectional Group Tree Building Packet Forwarding Bidir-PIM Configuration Task List Configuring Bidir-PIM Verifying Bidirectional Groups Monitoring and Maintaining Bidir-PIM Bidir-PIM Configuration Example Configuring Multicast Source Discovery Protocol How MSDP Works Page Benefits Prerequisites MSDP Configuration Task List Configuring an MSDP Peer Caching SA State Requesting Source Information from an MSDP Peer Controlling Source Information That Your Router Originates Redistributing Sources Filtering SA Request Messages Controlling Source Information That Your Router Forwards Using an MSDP Filter Using TTL to Limit the Multicast Data Sent in SA Messages Controlling Source Information That Your Router Receives Configuring a Default MSDP Peer Configuring an MSDP Mesh Group Shutting Down an MSDP Peer Including a Bordering PIM Dense Mode Region in MSDP Configuring an Originating Address Other Than the RP Address Monitoring and Maintaining MSDP MSDP Configuration Examples Default MSDP Peer Logical RP IPC-489 RouterA Configuration IPC-490 RouterB Configuration IPC-491 RouterE Configuration IPC-492 Configuring PGM Host and Router Assist PGM Overview Page PGM Host Configuration Task List Enabling PGM Host Enabling PGM Host with a Virtual Host Interface Enabling PGM Host with a Physical Interface Verifying PGM Host Configuration IPC-497 Use the show ip pgm host traffic command to display traffic statistics at the PGM transport layer: PGM Router Assist Configuration Task List Enabling PGM Router Assist Enabling PGM Router Assist with a Virtual Host Interface Enabling PGM Router Assist with a Physical Interface Monitoring and Maintaining PGM Host and Router Assist Monitoring and Maintaining PGM Host Monitoring and Maintaining PGM Router Assist PGM Host and Router Assist Configuration Examples PGM Host with a Virtual Interface Example PGM Host with a Physical Interface Example IPC-502 PGM Router Assist with a Virtual Interface Example PGM Router Assist with a Physical Interface Example IPC-503 Page Configuring Unidirectional Link Routing UDLR Overview UDLR Tunnel IGMP UDLR IGMP Proxy UDLR Tunnel Configuration Task List Prerequisite Configuring UDLR Tunnel Page IGMP UDLR Configuration Task List Configuring the IGMP UDL Changing the Distance for the Default RPF Interface Monitoring IGMP UDLR IGMP Proxy Configuration Task List Configuring IGMP Proxy Verifying IGMP Proxy UDLR Configuration Examples UDLR Tunnel Example IGMP UDLR Example IPC-515 Uplink Router (uplink-rtr) Configuration Downlink Router (downlink-rtr) Configuration IPC-516 IGMP Proxy Example IPC-517 IPC-518 Integrated UDLR Tunnel, IGMP UDLR, and IGMP Proxy Example Upstream Configuration IPC-519 Downstream Configuration IPC-520 Using IP Multicast Tools Multicast Routing Monitor Overview Benefits Restrictions MRM Configuration Task List Configuring a Test Sender and Test Receiver Monitoring Multiple Groups Configuring a Manager Conducting an MRM Test Monitoring IP Multicast Routing Monitoring and Maintaining MRM IPC-526 MRM Configuration Example Test Sender Configuration Test Receiver Configuration Manager Configuration Configuring Router-Port Group Management Protocol IP Multicast Routing Overview RGMP Overview IPC-529 Page RGMP Configuration Task List Enabling RGMP Verifying RGMP Configuration Monitoring and Maintaining RGMP IPC-534 RGMP Configuration Example IPC-535 Router D Configuration Switch A Configuration Switch B Configuration Page Configuring DVMRP Interoperability Basic DVMRP Interoperability Configuration Task List Configuring DVMRP Interoperability Responding to mrinfo Requests Configuring a DVMRP Tunnel Advertising Network 0.0.0.0 to DVMRP Neighbors Advanced DVMRP Interoperability Configuration Task List Enabling DVMRP Unicast Routing Limiting the Number of DVMRP Routes Advertised Changing the DVMRP Route Threshold Configuring a DVMRP Summary Address Disabling DVMRP Automatic summarization Adding a Metric Offset to the DVMRP Route Rejecting a DVMRP Nonpruning Neighbor Configuring a Delay Between DVRMP Reports Monitoring and Maintaining DVMRP DVMRP Configuration Examples DVMRP Interoperability Example DVMRP Tunnel Example IPC-546 Page Page INDEX Symbols A contents, displaying defining static B Page C D E F G H I IP access lists extended (example) description Page Page advertising clearing cache buffer, clearing displaying requests information, displaying interface parameters description enabling packet forwarding enabling (example) configuring description mode, enabling network configuring IP source address limiting rate groups covered mapping agent description (example) configuring description (example) ARP and NHRP configuring description Page (example) LSP flooding output of show commands routing level K L M Page N O P Q R Page (examples) configuring disabling EIGRP restrictions specified interfaces verifying S Page Page T U V W