Internet Engineering Task Force R. Kumar Internet-Draft A. Lohiya Intended status: Informational Juniper Networks Expires: August 2, 2017 M. Blanchet Viagenie January 29, 2017 Centralized Address Space Management(CASM) Problems and Use cases draft-kumar-casm-problem-and-use-cases-00 Abstract The organisations use IP Address Space Management (IPAM) tools to manage their IP address space, often with proprietary database and interfaces. This document describes evolution of IPAM into a standardized interfaces for centralized management of IP addresses. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on August 2, 2017. Copyright Notice Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of Kumar, et al. Expires August 2, 2017 [Page 1] Internet-Draft Centralized Address Space Management January 2017 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Address Space Management Use cases . . . . . . . . . . . . . 3 4.1. DHCP server pool . . . . . . . . . . . . . . . . . . . . 3 4.2. Static address configuration . . . . . . . . . . . . . . 3 4.3. Public IP address pool . . . . . . . . . . . . . . . . . 4 4.4. Multicast IP address pool . . . . . . . . . . . . . . . . 4 4.5. SDN controllers . . . . . . . . . . . . . . . . . . . . . 4 5. Legacy address space management (IPAM) systems . . . . . . . 4 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 8. Security Considerations . . . . . . . . . . . . . . . . . . . 5 9. Informative References . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction The address space management is an intergral part of any network management solution. The network may be based on legacy design or a more modern private and public cloud, the network may be big or small but every network operator need to manage the addressing needs of network elements. Typically, network operators write proprietary scripts or use cheat sheets to manage the addressing requirements. In recent trends, open source communities have developed tools to manage available IP addreess space. The open source or proprietray tools and scripts are collectively known as Internet Protocol Address Management (IPAM) system. The organizations use IPAM system to manage their IP address space, often with proprietary database and interfaces. One of the biggest challenges with IPAM systems, is lack of standardized interface for allocation, storing and retrieving information. This document describes a diverse set of use cases for a IPAM system and the probelms identfied with current IPAM approach. The problems identifed here should become the basis for a new vision defined as Centralized Address Space Management (CSAM). Kumar, et al. Expires August 2, 2017 [Page 2] Internet-Draft Centralized Address Space Management January 2017 2. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. 3. Terminology CASM: Centralized Address Space Management IPAM: IP Address Management 4. Address Space Management Use cases The address space management is an intergral part of any network management solution. Every device in the network be it a physical or virtual, needs an IP address for communication with other devices in the network. There is an absolute requirement that a network operator must find a way to assign address to these devices. The address management could be as simple as having one address pool from where addresses are allocated or may a much more complex scheme based on various requirements and nature of the network. This section is going to identfiy few top uses cases of address management. 4.1. DHCP server pool One of the most common method to assign an IP address to a device or function is DHCP. A device may request one or more IP addresses. The DHCP server on network handles all the DHCP requests and assign IP addresses. These addresses are allocated from a pre-defined address pool. A DHCP server might need multiple address pools if it manages DHCP request on multiple network segments. An address management system may be used to initialize these address pools on DHCP servers or could also be configured statically. But the static assigment is prone to misconfiguration and if the DHCP server is ever replaced, the new server must be configured with the same old pool. 4.2. Static address configuration Some devices or functions do not rely on DHCP protocols to obtain an IP address. This could be due to lack of DHCP client functionality or lack of DHCP server avaialable in the network segement for whatever reason. In such situations, an IP address may be configured statically but static IP address assignment is prone to errors as Kumar, et al. Expires August 2, 2017 [Page 3] Internet-Draft Centralized Address Space Management January 2017 mentioned earlier. The better way is to use an address management system for configuring devices without DHCP support. 4.3. Public IP address pool The public IPv4 addresses are very precious resources and should be used very carefully. A given organization may have a small number of these addresses, so it must find a way to allocate and free these resources effectively. The manual configuration mechanism may not be the best way to manage this resource. 4.4. Multicast IP address pool The multicast addresses are used for distributing broadcast contents. The multicast content distributor must be assigned an address and the content consumer must somehow figure out that address. This is usually configured manually or throgh proprietary mechanisms. 4.5. SDN controllers In order to build private or public clouds, address management of virtual machines, virtual functions and overlay networks is a very important task. In addition, the network operator also need to manage addressing of undelay network elements. The SDN controllers and underlay management systems must coordinate addressing schemes to ensure smooth operation. There is need for one address management system that would meet the requirements of such a network deployment. In order to create overlay networks and virtual workloads, the SDN controller also manage MAC addresses to assign to virtual network interfaces. But this is typically not handled by IPAM systems. 5. Legacy address space management (IPAM) systems As mentioned earlier, address management is a central component of every network management system. Organizations small or large deploy different ways of achieving this; some write their own scripts or use cheat sheets, and others use open source tools. These systems may not be suitable for all kind of uses cases due to lack of functionality and moreover the interfaces to these systems are closed which makes migration from one system to other difficult. Although, the functionality of IPAM systems vary from vendor to vendor but in general as a whole, following drawbacks exists: o Lack of common set of standard interfaces across IPAM system vendors Kumar, et al. Expires August 2, 2017 [Page 4] Internet-Draft Centralized Address Space Management January 2017 o Address usually allocated with very little or no context o Lacks ability to annotate requests with user-defined attributes as private or public address o Lacks capability to manage both unicast and multicast addresses o MAC address and network segment (VLAN) does not given enough information about user or usages o Lack of built-in multi-tetancy into interfaces o Lack of information about address requester such as virtual or physical device o Lack of integration with name services such as DNS o Lack of integration with DHCP server to get address records o Lack of integration with address translation services such as NAT44 and NAT64 The purpose is not to show a laudry list of deficiencies in the available IPAM system but to show a need to develop a new system that can meet the address allocation requirements of modern network architectures that gives consumers a portable way to use these systems. 6. Acknowledgements This document started from a slide deck authored by Rakesh Kumar and Anil Lohiya. 7. IANA Considerations This memo includes no request to IANA. 8. Security Considerations TBD 9. Informative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . Kumar, et al. Expires August 2, 2017 [Page 5] Internet-Draft Centralized Address Space Management January 2017 Authors' Addresses Rakesh Kumar Juniper Networks 1133 Innovation Way Sunnyvale, CA 94089 US Email: rkkumar@juniper.net Anil Lohiya Juniper Networks 1133 Innovation Way Sunnyvale, CA 94089 US Email: alohiya@juniper.net Marc Blanchet Viagenie 246 Aberdeen Quebec, QC G1R 2E1 Canada Email: marc.blanchet@viagenie.ca URI: http://viagenie.ca Kumar, et al. Expires August 2, 2017 [Page 6]