Cisco ASR 9000 Series Aggregation Services Router IP Addresses and Services Configuration Guide, Release 5.1.x First Published: 2013-09-02 Last Modified: 2014-04-01 Americas Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA http://www.cisco.com Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 527-0883 Text Part Number: OL-30398-07 THE SPECIFICATIONS AND INFORMATION REGARDING THE PRODUCTS IN THIS MANUAL ARE SUBJECT TO CHANGE WITHOUT NOTICE. ALL STATEMENTS, INFORMATION, AND RECOMMENDATIONS IN THIS MANUAL ARE BELIEVED TO BE ACCURATE BUT ARE PRESENTED WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED. USERS MUST TAKE FULL RESPONSIBILITY FOR THEIR APPLICATION OF ANY PRODUCTS. THE SOFTWARE LICENSE AND LIMITED WARRANTY FOR THE ACCOMPANYING PRODUCT ARE SET FORTH IN THE INFORMATION PACKET THAT SHIPPED WITH THE PRODUCT AND ARE INCORPORATED HEREIN BY THIS REFERENCE. IF YOU ARE UNABLE TO LOCATE THE SOFTWARE LICENSE OR LIMITED WARRANTY, CONTACT YOUR CISCO REPRESENTATIVE FOR A COPY. The Cisco implementation of TCP header compression is an adaptation of a program developed by the University of California, Berkeley (UCB) as part of UCB's public domain version of the UNIX operating system. All rights reserved. Copyright © 1981, Regents of the University of California. NOTWITHSTANDING ANY OTHER WARRANTY HEREIN, ALL DOCUMENT FILES AND SOFTWARE OF THESE SUPPLIERS ARE PROVIDED “AS IS" WITH ALL FAULTS. CISCO AND THE ABOVE-NAMED SUPPLIERS DISCLAIM ALL WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, THOSE OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OR ARISING FROM A COURSE OF DEALING, USAGE, OR TRADE PRACTICE. IN NO EVENT SHALL CISCO OR ITS SUPPLIERS BE LIABLE FOR ANY INDIRECT, SPECIAL, CONSEQUENTIAL, OR INCIDENTAL DAMAGES, INCLUDING, WITHOUT LIMITATION, LOST PROFITS OR LOSS OR DAMAGE TO DATA ARISING OUT OF THE USE OR INABILITY TO USE THIS MANUAL, EVEN IF CISCO OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental. Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: http:// www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R) © 2014 Cisco Systems, Inc. All rights reserved. CONTENTS Preface Preface xvii Changes to This Document xvii Obtaining Documentation and Submitting a Service Request xviii CHAPTER 1 New and Changed Feature Information in Cisco IOS XR Release 5.1.x 1 New and Changed IP Addresses and Services Features 1 CHAPTER 2 Implementing Access Lists and Prefix Lists 7 Prerequisites for Implementing Access Lists and Prefix Lists 8 Restrictions for Implementing Access Lists and Prefix Lists 8 Hardware Limitations 10 Information About Implementing Access Lists and Prefix Lists 10 Access Lists and Prefix Lists Feature Highlights 10 Purpose of IP Access Lists 10 How an IP Access List Works 11 IP Access List Process and Rules 11 Helpful Hints for Creating IP Access Lists 12 Source and Destination Addresses 12 Wildcard Mask and Implicit Wildcard Mask 12 Transport Layer Information 12 IP Access List Entry Sequence Numbering 12 Sequence Numbering Behavior 13 IP Access List Logging Messages 13 Extended Access Lists with Fragment Control 14 Policy Routing 16 Comments About Entries in Access Lists 16 Access Control List Counters 16 Cisco ASR 9000 Series Aggregation Services Router IP Addresses and Services Configuration Guide, Release 5.1.x OL-30398-07 iii Contents BGP Filtering Using Prefix Lists 17 How the System Filters Traffic by Prefix List 17 Information About Implementing ACL-based Forwarding 18 ACL-based Forwarding Overview 18 ABF-OT 18 IPv6 ACL Based Forwarding Object Tracking 18 IPSLA support for Object tracking 18 ACL Counters Using SNMP 19 How to Implement Access Lists and Prefix Lists 19 Configuring Extended Access Lists 19 Applying Access Lists 22 Controlling Access to an Interface 22 Controlling Access to a Line 23 Configuring Prefix Lists 24 Configuring Standard Access Lists 26 Copying Access Lists 28 Sequencing Access-List Entries and Revising the Access List 29 Copying Prefix Lists 31 Sequencing Prefix List Entries and Revising the Prefix List 32 How to Implement ACL-based Forwarding 33 Configuring ACL-based Forwarding with Security ACL 33 Implementing IPSLA-OT 35 Enabling track mode 35 Configuring track type 36 Configuring tracking type (line protocol) 36 Configuring track type (list) 37 Configuring tracking type (route) 37 Configuring tracking type (rtr) 38 Configuring Pure ACL-Based Forwarding for IPv6 ACL 39 ACL-Chaining 40 ACL-Chaining Overview 40 Restrictions for Common ACL 41 Configuring an Interface to accept Common ACL 41 ACL Scale Enhancements 42 ACL Scale Enhancements: Backward Compatibility 42 Cisco ASR 9000 Series Aggregation Services Router IP Addresses and Services Configuration Guide, Release 5.1.x iv OL-30398-07 Contents Configuring a Network Object-Group 43 Configuring a Port Object-Group 44 Configuring ACL with Object-Groups 45 Atomic ACL Updates By Using the Disable Option 47 Modifying ACLs when Atomic ACL Updates are Disabled 48 Configuring ACL Counters for SNMP Query 50 Configuration Examples for Implementing Access Lists and Prefix Lists 51 Resequencing Entries in an Access List: Example 51 Adding Entries with Sequence Numbers: Example 52 Adding Entries Without Sequence Numbers: Example 52 Atomic ACL Updates By Using the Disable Option 53 Modifying ACLs when Atomic ACL Updates are Disabled 53 IPv6 ACL in Class Map 55 Configuring IPv6 ACL QoS - An Example 56 IPv4/IPv6 ACL over BVI interface 58 Configuring IPv4 ACL over BVI interface - An Example 59 Configuring ABFv4/v6 over IRB/BVI interface 59 Configuring ABFv4 over IRB/BVI interface: Example 62 Configuring ABFv6 over IRB/BVI interface: Example 62 Configuring an Interface to accept Common ACL - Examples 63 Configuring ACL Counters for SNMP Query: Example 64 Additional References 65 CHAPTER 3 Configuring ARP 67 Prerequisites for Configuring ARP 67 Restrictions for Configuring ARP 68 Information About Configuring ARP 68 IP Addressing Overview 68 Address Resolution on a Single LAN 69 Address Resolution When Interconnected by a Router 69 ARP and Proxy ARP 69 ARP Cache Entries 70 Direct Attached Gateway Redundancy 70 Additional Guidelines 71 How to Configure ARP 71 Cisco ASR 9000 Series Aggregation Services Router IP Addresses and Services Configuration Guide, Release 5.1.x OL-30398-07 v Contents Defining a Static ARP Cache Entry 71 Enabling Proxy ARP 72 Enabling Local Proxy ARP 73 Configuring DAGR 74 Configuring ARP purge-delay 76 Configuring ARP timeout 77 Configure Learning of Local ARP Entries 78 Configuration Examples for ARP Configuration on Cisco IOS XR Software 79 Creating a Static ARP Cache Entry: Example 79 Enabling Proxy ARP: Example 80 80 Enabling DAGR and Configuring a DAGR Group: Example 80 Displaying the Operational State of DAGR Groups: Example 80 Additional References 80 CHAPTER 4 Implementing Cisco Express Forwarding 83 Prerequisites for Implementing Cisco Express Forwarding 83 Information About Implementing Cisco Express Forwarding Software 84 Key Features Supported in the Cisco Express Forwarding Implementation 84 Benefits of CEF 84 CEF Components 85 Border Gateway Protocol Policy Accounting 85 Reverse Path Forwarding (Strict and Loose) 86 Per-Flow Load Balancing 87 BGP Attributes Download 88 How to Implement CEF 88 Verifying CEF 88 Configuring BGP Policy Accounting 89 Verifying BGP Policy Accounting 94 Configuring a Route Purge Delay 96 Configuring Unicast RPF Checking 96 Configuring Modular Services Card-to-Route Processor Management Ethernet Interface Switching 97 Configuring Per-Flow Load Balancing 98 Configuring 3-Tuple Hash Algorithm 98 Cisco ASR 9000 Series Aggregation Services Router IP Addresses and Services Configuration Guide, Release 5.1.x vi OL-30398-07 Contents Configuring BGP Attributes Download 99 Configuring BGP Attributes Download 99 IPv6 Routing over IPv4 MPLS TE Tunnels 100 Restrictions for Implementing IPv6 routing over IPv4 MPLS TE tunnels 100 Configuring tunnel as IPV6 Forwarding-Adjacency 100 Configuring tunnel as IPV6 interface 101 Configuration Examples for Implementing CEF on Routers Software 101 Configuring BGP Policy Accounting: Example 102 Verifying BGP Policy Statistics: Example 105 Configuring Unicast RPF Checking: Example 116 Configuring the Switching of Modular Services Card to Management Ethernet Interfaces on the Route Processor: Example 116 Configuring Per-Flow Load Balancing: Example 116 Configuring BGP Attributes Download: Example 117 Additional References 117 CHAPTER 5 Implementing the Dynamic Host Configuration Protocol 119 Prerequisites for Configuring DHCP Relay Agent 120 Information About DHCP Relay Agent 120 Secure ARP 121 How to Configure and Enable DHCP Relay Agent 121 Configuring and Enabling the DHCP Relay Agent 121 Configuring a DHCP Relay Profile 122 Enabling DHCP Relay Agent on an Interface 123 Disabling DHCP Relay on an