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Cisco CNS Address and Name Registrar

Cisco CNS Address and Name Registrar 2.0 Q&A

Q & A

Cisco Address and Name
Registrar 2.0

Overview

Q. What are the major features of Cisco Address and Name Registrar (ANR) 2.0?

A. The major features are:

  • Address Space Allocation and Reclamation

    • Cisco ANR dynamically allocates and reclaims IP address space for multiple administratively assigned owners.

    • Cisco ANR supports the creation and management of multiple IP address blocks for each owner, allocating subnetted address space to a Cisco Network Registrar Dynamic Host Configuration Protocol (DHCP) server and among cable modem termination system (CMTS) interfaces as defined by user-customized policy and parameters.

    • Cisco ANR implements event triggers to perform customizable actions (including "alert administrator" and "allocate additional IP address space") when configurable IP utilization thresholds have been reached.

  • Cisco Network Registrar Configuration

    • Cisco ANR adds DHCP scopes to the Cisco Network Registrar server upon IP address space allocation.

    • Cisco ANR uses owner-specific templates to assign policies and selection tags to new DHCP scopes in Cisco Network Registrar.

    • Synchronization is maintained between Cisco ANR and Cisco Network Registrar, ensuring that Cisco ANR will recognize any manual changes made to a Cisco Network Registrar server.

    • Cisco ANR supports IP address allocation into DHCP fail-over configurations (both simple and symmetric).

  • CMTS Configuration and Multiprotocol Label Switching virtual private network (MPLS VPN) Integration

    • Cisco ANR creates a new subinterface per owner on the appropriate CMTS interface when it initially allocates IP address space.

    • Additional IP address space for a known owner is added as a secondary IP address to that owner's existing subinterface.

    • Synchronization is maintained between Cisco ANR and CMTSs, ensuring that Cisco ANR will recognize manual changes made to a CMTS.

    • Cisco ANR can fully interoperate in a MPLS VPN environment working in conjunction with the Cisco VPN Solutions Center (VPN-SC) to configure CMTSs for MPLS VPN across the network.

  • Utilization Reporting

    • Cisco ANR provides IP address utilization information on a per-DHCP scope, per-CMTS, per-interface, per-address block, and per-owner basis.

    • Utilization data provided by Cisco ANR can be used to predict trends in IP consumption by monitoring and tracking IP usage over customized time periods.

For additional information on the features and benefits of Cisco ANR, see the Cisco ANR 2.0 data sheet.

Q. What is the recommended server configuration for Cisco ANR?

A. The minimum recommended configuration for Cisco ANR installation is a Sun Ultra 5 workstation with 256 MB of RAM, 512 MB of swap space, and 120 MB of disk space. Additional disk space required for operation will be dependent on the number of IP address blocks under management by Cisco ANR, and the number of CMTSs and interfaces known to Cisco ANR. Although actual disk space will vary between deployments, it is expected that 500 MB will be sufficient for most installations.

Q. What operating systems does Cisco ANR support?

A. Cisco ANR 2.0 is supported on the Solaris 8 operating system.

Q. Why is this version of Cisco ANR called Version 2.0, even though it is the first available release?

A. Cisco ANR 2.0 is the first generally available release of the Address and Name Registrar product; however, a previous version was released in limited availability to a handful of customers. To distinguish between the previous version, and to call out the substantial changes in the product since the last major release, the 2.0 nomenclature was adopted for this version.

Q. What network components are required for Cisco ANR operation?

A. Cisco ANR requires a Cisco Network Registrar DHCP server (Version 5.0.7 or later) as well as one or more Cisco CMTSs.

Q. Does Cisco ANR provide any integration points that could be used to advantage for custom applications?

A. Cisco ANR provides a Java application programming interface (API) that is implemented using the Simple Object Access Protocol (SOAP) standard on top of Extensible Markup Language (XML). A Javadoc is provided with the Cisco ANR 2.0 Software download or CD as API documentation. Customers are cautioned that the API could change slightly from release to release. Cisco has every intention of maintaining API compatibility between versions, but please check with your Cisco support organization before migrating custom applications from the Cisco ANR 2.0 to a later release.

Q. Can I generate my own custom reports with the utilization data collected by Cisco ANR?

A. Cisco ANR collects IP utilization information from the Cisco Network Registrar DHCP server at specified intervals. Cisco ANR then stores the utilization data in its internal database, where it will remain until the administrator chooses to explicitly delete the data through the utilization purge command.

The internal Cisco ANR database, the Sybase Adaptive Server Anywhere, is Open Database Connectivity (ODBC) compliant. It enables you to use third-party reporting tools to access Cisco ANR data and generate customer reports.

Q. Why does Cisco ANR assign owners to address blocks?

A. Owner is a Cisco ANR-specific term used to correlate IP address blocks with an entity for which that space should be tracked and managed. The owner assignment gives an administrator the ability to query utilization and allocate IP space specific to one organizational entity.

For example, a network provider could be managing IP address space on behalf of multiple Internet service provider (ISP) partners. Using Cisco ANR, the network provider could assign the 123.45.0.0/16 address block to ISP1 and the 234.56.0.0/16 address block to ISP2. ISP1 and ISP2 are considered owners within the Cisco ANR data model, in this example. The owner correlation could be used to allocate ISP1 IP addresses to only those CMTSs with ISP1 subscribers, for example, or to query IP utilization for all of the ISP2 IP address space.

Q. How does Cisco ANR help in a managed access environment?

A. Many managed access environments call for network providers to manage the IP address space on behalf of their service-provider partners. In these scenarios, IP address management becomes more complicated for the network provider because IP address space needs to be allocated and tracked for multiple, disparate IP owners.

Cisco ANR helps by monitoring, tracking, distributing, and managing IP address space, even in the most complicated network configurations. Cisco ANR also automatically updates hardware configurations to reflect IP address allocation decisions. Automating IP address management improves accuracy of data, increases operational efficiency, and reduces manual operational processes.

The Cisco ANR ability to monitor on IP address space by owner (see question "Why does Cisco ANR assign owners to address blocks?) also gives a network provider the ability to do queries or management activities on behalf of one specific service provider, as might be called for in a managed access environment.

Q. What are the user interfaces to Cisco ANR?

A. All configuration and administration of the Cisco ANR server can be done through the anrsh command-line interface (CLI). Cisco ANR also provides a Java API that is implemented using the SOAP standard on top of XML.

Q. How does Cisco ANR determine IP address utilization on the network?

A. Cisco ANR collects IP utilization information from the Cisco Network Registrar DHCP server at administrator-specified intervals. Cisco ANR then stores the utilization data in its internal database, where it will remain until the administrator chooses to explicitly delete the data through the utilization purge command.

Q. How can IP address utilization be reported?

A. Cisco ANR is able to provide IP address utilization information on a per-DHCP scope, per-CMTS, per-interface, per-address block (subnet and supernet), and per-owner basis. Reports can be run and displayed using the Cisco ANR CLI, anrsh. (See question "Can I generate my own custom reports with the utilization data collected by Cisco ANR?" for information on generating custom reports.)

Q. Can Cisco ANR be used to predict IP address consumption on the network?

A. Cisco ANR tracks IP consumption and correlates this data across disparate networks, CMTS hardware, and IP owners. Historic utilization information can be used to advantage to monitor and predict trends in IP consumption. With an understanding of past IP allocation and usage, administrators can make proactive decisions about future demand and IP address requirements.

Q. What databases are supported in Cisco ANR?

A. Cisco ANR uses its own internal/embedded database (the Sybase Adaptive Server Anywhere) that requires no tuning or manual administration. Through this approach, Cisco has been able to optimize data storage and retrieval to achieve maximum functionality and performance for Cisco ANR. No additional or external database is required.

Q. How does Cisco ANR assist in renumbering my network?

A. Cisco ANR helps renumber the network by allocating new and reclaiming old IP address blocks.

For example, if the IP address space for owner1 is reaching maximum utilization, Cisco ANR can push a new, larger IP address block to a Network Registrar server on behalf of owner1, and then deactivate the smaller owner1 IP block. All DHCP devices getting IP addresses out of the old, small IP block will renew their leases and get addresses out of the new, large IP address block. After one lease period has passed, it is reasonable to expect no devices to have IP addresses from the old, small block, and Cisco ANR can be used to reclaim the inactive IP address space.

Integration with Cisco Software

Q. Is any additional Cisco software required to run Cisco ANR?

A. Cisco Network Registrar Version 5.0.7 or later is required with Cisco ANR 2.0. No other software is required.

Q. Which version(s) of Cisco Network Registrar integrate with Cisco ANR?

A. Cisco ANR 2.0 integrates with Cisco Network Registrar Version 5.0.7 or later.

Q. With how many Cisco Network Registrar DHCP servers can Cisco ANR integrate?

A. Cisco ANR 2.0 can manage IP address space on one Cisco Network Registrar server plus its DHCP fail-over partner.

Q. How does Cisco ANR talk to Cisco Network Registrar?

A. Cisco ANR 2.0 talks to Cisco Network Registrar through nrcmd, the Cisco Network Registrar CLI.

Q. Can I control the DHCP policies for IP address space established in Cisco Network Registrar by Cisco ANR?

A. When Cisco ANR pushes IP address space to a Cisco Network Registrar DHCP server, it assigns an owner-specific template to the DHCP scope containing the IP address space. The template includes a DHCP policy and Cisco Network Registrar-specific scope selection tags.

Q. Does Cisco ANR integrate with third-party DHCP servers?

A. No. Cisco ANR 2.0 integrates only with the Cisco Network Registrar DHCP server.

Q. Can I use Cisco ANR to control Cisco Network Registrar?

A. Cisco ANR is a management system that can help configure IP address space on a Cisco Network Registrar server. Additionally, the Cisco ANR CLI, anrsh, can be used to issue commands on the Cisco Network Registrar server using the server execute command. The server execute command pushes requests to a specified Cisco Network Registrar server CLI, nrcmd. Note that in any scenario Cisco Network Registrar remains the authoritative data store for all Cisco Network Registrar-related information. More information on this functionality can be found in the Cisco ANR 2.0 Users Guide.

Q. Where does authoritative information about DHCP leases reside?

A. Cisco Network Registrar remains the authoritative source for all DHCP-related information, including DHCP lease data.

Q. Can Cisco ANR help enable MPLS VPNs?

A. Yes. Cisco ANR establishes IP address space on CMTS subinterfaces to assist with MPLS VPN configuration.

Cisco ANR configures IP address space to establish one subinterface per owner per CMTS line card. Specifically, upon initial allocation of IP address space for a particular owner, Cisco ANR creates a new subinterface on the appropriate CMTS interface. When additional IP address space is added to a CMTS interface for a known owner, Cisco ANR adds a secondary IP address for the new subnet to the appropriate subinterface.

With MPLS VPN Virtual Routing and Forwarding (VRF) tables assigned to subinterfaces on CMTSs, one VRF per "owner" will be required, and traffic from owner1 subscribers will always be routed to the owner1 network using the same MPLS path.

Integration with Network Hardware

Q. With what Cisco hardware does Cisco ANR integrate?

A. Cisco ANR integrates with the Cisco uBR7246 and uBR7223 running Cisco IOS® Version 12.1EC. Additional Cisco uBR versions are being tested for Cisco ANR integration. Please ask an appropriate Cisco representative for the most current hardware integration list.

Q. How does Cisco ANR talk to Cisco uBRs?

A. Cisco ANR communicates with the Cisco uBR using Telnet. Cisco ANR will need to be made aware of the username, Telnet password, and enable password it should use to access the Cisco uBR.

Q. How does Cisco ANR establish IP address space on a Cisco uBR?

A. Cisco ANR allocates IP address space to establish one subinterface per owner per CMTS physical interface.

Upon initial allocation of IP address space for a particular owner, Cisco ANR creates a new subinterface on the appropriate CMTS interface. When additional IP address space is added to a CMTS interface for a known owner, Cisco ANR adds a secondary IP address for the new subnet to the appropriate subinterface.

Please refer to Cisco IOS documentation for detailed information on using subinterface configuration with Cisco uBRs.

Q. Can I use interface bundling on my Cisco uBRs if I am using Cisco ANR?

A. Yes. Interface bundling is supported in conjunction with Cisco ANR.

Q. How is information about the IP address space added to one Cisco uBR by Cisco ANR distributed to other routers?

A. The Cisco uBR routing protocol configuration should include the redistribute connected command to enable knowledge of address space added by Cisco ANR to be communicated to other Cisco uBRs.

Q. Can I have two separate instances of Cisco ANR managing the same Cisco uBR?

A. Two separate Cisco ANR 2.0 instances can manage IP address space on the same Cisco uBR. Each instance of Cisco ANR can create and manage subinterfaces and IP address space on one Cisco uBR, and Cisco ANR/uBR synchronization will ensure that configuration changes made by Cisco ANR instance 1 will be known by Cisco ANR instance 2. No additional coordination is required.

Q. Where does authoritative information about Cisco uBR configurations reside?

A. The Cisco uBR remains the authoritative source for all Cisco uBR-related information.