Network Management Research Group S. Jiang Internet-Draft Huawei Technologies Co., Ltd Intended status: Informational B. Carpenter Expires: April 5, 2015 Univ. of Auckland M. Behringer Cisco Systems October 2, 2014 Gap Analysis for Autonomic Networking draft-irtf-nmrg-an-gap-analysis-02 Abstract This document provides a problem statement and gap analysis for an IP-based autonomic network that is mainly based on distributed network devices. The document provides a background by reviewing the current status of autonomic aspects of IP networks and the extent to which current network management depends on centralisation and human administrators. Finally the document describes the general gaps between current network abilities and the ideal autonomic network concept. 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 April 5, 2015. Copyright Notice Copyright (c) 2014 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 Jiang, et al. Expires April 5, 2015 [Page 1] Internet-Draft Autonomic Networking Gap Analysis October 2014 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 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Background . . . . . . . . . . . . . . . . . . . . . . . . . 3 3.1. Automatic and Autonomic Aspects of Current IP Networks . 3 3.1.1. IP Address Management and DNS . . . . . . . . . . . . 3 3.1.2. Routing . . . . . . . . . . . . . . . . . . . . . . . 4 3.1.3. Configuration of Default Router in a Host . . . . . . 5 3.1.4. Hostname Lookup . . . . . . . . . . . . . . . . . . . 5 3.1.5. User Authentication and Accounting . . . . . . . . . 5 3.1.6. Security . . . . . . . . . . . . . . . . . . . . . . 6 3.1.7. Synchronization . . . . . . . . . . . . . . . . . . . 6 3.1.8. Miscellaneous . . . . . . . . . . . . . . . . . . . . 7 3.2. Current Non-Autonomic Behaviors . . . . . . . . . . . . . 7 3.2.1. Network Establishment . . . . . . . . . . . . . . . . 7 3.2.2. Network Maintenance and Management . . . . . . . . . 8 3.2.3. Security Setup . . . . . . . . . . . . . . . . . . . 9 3.2.4. Troubleshooting and Recovery . . . . . . . . . . . . 9 4. Features Needed by Autonomic Networks . . . . . . . . . . . . 10 4.1. More Coordination among Devices or Network Partitions . . 10 4.2. Reusable Common Components . . . . . . . . . . . . . . . 11 4.3. Secure Control Plane . . . . . . . . . . . . . . . . . . 11 4.4. Less Configuration . . . . . . . . . . . . . . . . . . . 12 4.5. Forecasting and Dry Runs . . . . . . . . . . . . . . . . 12 4.6. Benefit from Knowledge . . . . . . . . . . . . . . . . . 13 5. Security Considerations . . . . . . . . . . . . . . . . . . . 13 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 8. Change log [RFC Editor: Please remove] . . . . . . . . . . . 14 9. Informative References . . . . . . . . . . . . . . . . . . . 14 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 1. Introduction The general goals and relevant definitions for autonomic networking are discussed in [I-D.irtf-nmrg-autonomic-network-definitions]. In summary, the fundamental goal of an autonomic network is self- management, including self-configuration, self-optimization, self- healing and self-protection. Whereas interior gateway routing protocols such as OSPF and IS-IS largely exhibit these properties, Jiang, et al. Expires April 5, 2015 [Page 2] Internet-Draft Autonomic Networking Gap Analysis October 2014 most other aspects of networking require top-down configuration, often involving human administrators and a considerable degree of centralisation. In essence Autonomic Networking is putting all network configurations onto the same footing as routing, limiting manual or database-driven configuration to an essential minimum. It should be noted that this is highly unlikely to eliminate the need for human administrators, because many of their essential tasks will remain. The idea is to eliminate tedious and error-prone tasks, for example manual calculations, cross-checking between two different configuration files, or tedious data entry. Higher level operational tasks, and complex trouble-shooting, will remain to be done by humans. This document first provides background by identifying examples of partial autonomic behavior in the Internet, and by describing important areas of non-autonomic behavior. Based on these observations, it then describes missing general mechanisms which would allow autonomic behaviours to be added throughout the Internet. 2. Terminology The terminology defined in [I-D.irtf-nmrg-autonomic-network-definitions] is used in this document. 3. Background 3.1. Automatic and Autonomic Aspects of Current IP Networks This section discusses the history and current status of automatic or autonomic operations in various aspects of network configuration, in order to establish a baseline for the gap analysis. In particular, routing protocols already contain elements of autonomic processes, such as information exchange and state synchronization. 3.1.1. IP Address Management and DNS Originally there was no alternative to completely manual and static management of IP addresses. Once a site had received an IPv4 address assignment (usually a Class C /24 or Class B /16, and rarely a Class A /8) it was a matter of paper-and-pencil design of the subnet plan (if relevant) and the addressing plan itself. Subnet prefixes were manually configured into routers, and /32 addresses were assigned administratively to individual host computers, and configured manually by system administrators. Records were typically kept in a plain text file or a simple spreadsheet. Jiang, et al. Expires April 5, 2015 [Page 3] Internet-Draft Autonomic Networking Gap Analysis October 2014 Clearly this method was clumsy and error-prone as soon as a site had more than a few tens of hosts, but it had to be used until DHCP [RFC2131] became a viable solution during the second half of the 1990s. DHCP made it possible to avoid manual configuration of individual hosts (except, in many deployments, for a small number of servers configured with static addresses). In terms of management, it is difficult to separate IP address management from DNS management. At roughly the same time as DHCP came into widespread use, it became very laborious to manually maintain DNS source files in step with IP address assignments. Because of reverse DNS lookup, it also became necessary to synthesise DNS names even for hosts that only played the role of clients. Therefore, it became necessary to synchronise DHCP server tables with forward and reverse DNS. For this reason, Internet Protocol address management tools emerged. These are, however, a centralised and far from autonomic type of solution. A related issue is prefix delegation, especially in IPv6 when more than one prefix may be delegated to the same physical subnet. DHCPv6 Prefix Delegation [RFC3633] is a useful solution, but how this topic is to be handled in home networks is still an open question. Still further away is automated assignment and delegation of IPv4 subnet prefixes. Another complication is the possibility of Dynamic DNS Update [RFC2136]. With appropriate security, this is an autonomic approach, where no human intervention is required to create the DNS records for a host. Also, there are coexistence issues with a traditional DNS setup. 3.1.2. Routing Since a very early stage, it has been a goal that Internet routing should be self-healing when there is a failure of some kind in the routing system (i.e. a link or a router goes wrong). Also, the problem of finding optimal routes through a network was identified many years ago as a problem in mathematical graph theory, for which well known algorithms were discovered (the Dijkstra and Bellman-Ford algorithms). Thus routing protocols became largely autonomic in the 1980s, as soon as the network was large enough for manual configuration of routing tables to become difficult. IGP routers do need some initial configuration data to start up the autonomic routing protocol. Also, BGP-4 routers need detailed static configuration of routing policy data. Jiang, et al. Expires April 5, 2015 [Page 4] Internet-Draft Autonomic Networking Gap Analysis October 2014 3.1.3. Configuration of Default Router in a Host Originally this was a manual operation. Since the deployment of DHCP, this has been automatic as far as most IPv4 hosts are concerned, but the DHCP server must be appropriately configured. In simple environments such as a home network, the DHCP server resides in the same box as the default router, so this configuration is also automatic. In more complex environments, where an independent DHCP server or a local DHCP relay is used, DHCP configuration is more complex and not automatic. In IPv6 networks, the default router is provided by Router Advertisement messages [RFC4861] from the router itself, and all IPv6 hosts make use of it. The router may also provide more complex Route Information Options. The process is essentially autonomic as far as all IPv6 hosts are concerned, and DHCPv6 is not involved. However, there are still open issues when more than one prefix is in use on a subnet and more than one first-hop router may be available as a result. 3.1.4. Hostname Lookup Originally host names were looked up in a static table, often referred to as /etc/hosts from its traditional file path in Unix systems. When the DNS was deployed during the 1980s, all hosts needed DNS resolver code, and needed to be configured with the IP addresses (not the names) of suitable DNS servers. Like the default router, these were originally manually configured. Today, they are provided automatically via DHCP or DHCPv6 [RFC3315]. For IPv6 end systems, there is also a way for them to be provided automatically via a Router Advertisement option. However, the DHCP or DHCPv6 server, or the IPv6 router, need to be configured with the appropriate DNS server addresses. 3.1.5. User Authentication and Accounting Originally, user authentication and accounting was mainly based on physical connectivity and the degree of trust that follows from direct connectivity. Network operators charged based on the set up of dedicated physical links with users. Automated user authentication was introduced by Point-to-Point Protocol [RFC1661], [RFC1994] and RADIUS protocol [RFC2865], [RFC2866] in early 1990s. As long as a user completes online authentication through the RADIUS protocol, the accounting for that user starts on the corresponding AAA server automatically. This mechanism enables business models with charging based on traffic based or time based usage. However, the management of user authentication information remains manual by network administrators. It also becomes complex in the case of Jiang, et al. Expires April 5, 2015 [Page 5] Internet-Draft Autonomic Networking Gap Analysis October 2014 mobile users who roam between operators, since prior relationships between the operators are needed. 3.1.6. Security Security has many aspects that need configuration and are therefore candidates to become autonomic. On the other hand, it is essential that a network's central policy should be applied strictly for all security configurations. As a result security has largely been based on centrally imposed configurations. Many aspects of security depend on policy, for example firewall policies. Policies are by definition human made and will therefore also persist in an autonomic environment. However, policies are becoming more high-level, abstracting for example addressing, and focusing on the user or application. The methods to manage, distribute and apply policy, and to monitor compliance and violations could be autonomic. Today, many security mechanisms show some autonomic properties. For example user authentication via 802.1x allows automatic mapping of users after authentication into logical contexts (typically VLANs). While today configuration is still very important, the overall mechanism displays signs of self-adaption to changing situations. BGP Flowspec [RFC5575] allows a partially autonomic threat defense mechanism, where threats are identified, the flow information is automatically distributed, and counter-actions can be applied. Today typically a human operator is still in the loop to check correctness, but over time such mechanisms can become more autonomic. Negotiation capabilities, present in many security protocols, also display simple autonomic behaviours. In this case a security policy about algorithm strength can be configured into servers but will propagate automatically to clients. 3.1.7. Synchronization Another area where autonomic processes between peers are involved is state synchronization. In this case, several devices start out with inconsistent state and go through a peer-to-peer procedure after which their states are consistent. Network time synchronisation [RFC5905] is a well-established example, guaranteeing that a participating node's clock state is synchronized with reliable time servers within a defined margin of error, without any overall controller being involved. Jiang, et al. Expires April 5, 2015 [Page 6] Internet-Draft Autonomic Networking Gap Analysis October 2014 3.1.8. Miscellaneous There are innumerable other properties of network devices and end systems that today need to be configured either manually or using a management protocol such as SNMP [RFC1157] or NETCONF [RFC6241]. In a truly autonomic network, all of these, without exception, would need to either have satisfactory default values or be configured automatically. Some examples are parameters for tunnels of various kinds, flows (in an SDN context), quality of service, service function chaining, energy management, system identification and NTP configuration. 3.2. Current Non-Autonomic Behaviors In current networks, many operations are still heavily dependent on human intelligence and decision, or on centralised top-down network management systems. These operations are the targets of Autonomic Network technologies. The ultimate goal of an Autonomic Network is to replace human and automated operations by autonomic functions, so that the networks can run independently without depending on a human or NMS system for routine details, while maintaining central control where required. Of course, there would still be the absolute minimum of human input required, particularly during the network establishment stage, and during emergencies and difficult trouble- shooting. This section analyzes the existing human and central dependencies in typical current networks and suggests cases where they could in principle be replaced by autonomic behaviors. 3.2.1. Network Establishment Network establishment requires network operators to analyze the requirements of the new network, design a network architecture and topology, decide device locations and capacities, set up hardware, design network services, choose and enable required protocols, configure each device and each protocol, set up central user authentication and accounting policies and databases, design and deploy security mechanisms, etc. Overall, these jobs are quite complex work that cannot become fully autonomic in the foreseeable future. However, part of these jobs may be able to become autonomic, such as detailed device and protocol configurations and database population. The initial network management policies/behaviors may also be transplanted from other networks and automatically localized. Jiang, et al. Expires April 5, 2015 [Page 7] Internet-Draft Autonomic Networking Gap Analysis October 2014 3.2.2. Network Maintenance and Management Network maintenance and management are very different for ISP networks and enterprise networks. ISP networks have to change much more frequently than enterprise networks, given the fact that ISP networks have to serve a large number of customers who have very diversified requirements. The current rigid model is that network administrators design a limited number of services for customers to order. New requirements of network services may not be able to be met quickly by human management. Given a real-time request, the response must be autonomic, in order to be flexible and quickly deployed. However, behind the interface, describing abstracted network information and user authorization management may have to depend on human intelligence from network administrators in the foreseeable future. User identification integration/consolidation among networks or network services is another challenge for autonomic network access. Currently, many end users have to manually manage their user accounts and authentication information when they switch among networks or network services. Classical network maintenance and management mainly manages the configuration of network devices. Tools have been developed to enable remote management and make such management easier. However, the decision about each configuration detail depends either on human intelligence or rigid templates. This is the source of most network configuration errors. It is also a barrier to increasing the utility of network resources, because the human managers cannot respond quickly enough to network events, such as traffic bursts, etc. For example, currently, a light load is normally assumed in network design because there is no mechanism to properly handle a sudden traffic flood. It is actually normal to avoid network crashes caused by traffic overload by wasting a huge amount of resources. It is worth noting that the introduction of new, more flexible, methods of network configuratiom, typified by software-defined networking (SDN), will only make this problem worse unless the details are managed autonomically. Autonomic decision processes for configuration would enable dynamic management of network resources (by managing resource-relevant configuration). Self-adapting network configuration would adjust the network into the best possible situation, which also prevents configuration errors from having lasting impact. Jiang, et al. Expires April 5, 2015 [Page 8] Internet-Draft Autonomic Networking Gap Analysis October 2014 3.2.3. Security Setup Setting up security for a network generally requires very detailed human intervention, or relies entirely on default configurations that may be too strict or too risky for the particular situation of the network. While some aspects of security are intrinsically top-down in nature (e.g. broadcasting a specific security policy to all hosts), others could be self-managed within the network. In an autonomic network, where nodes within a domain have a mutually verifiable domain identity, security processes could run entirely automatically. Nodes could identify each other securely, negotiating required security settings and even shared keys if needed. The location of trust anchors (certificate authority, registration authority), certificate revocation lists, policy server, etc., can be found by service discovery. Transactions such as a certificate revocation list download can be authenticated via a common trust anchor. Policy distribution can also be entirely automated, and secured via a common trust anchor. These concepts lead to a network where the intrinsic security is automatic and applied by default, i.e., a "self-protecting" network. For further discussion, see [I-D.behringer-default-secure] 3.2.4. Troubleshooting and Recovery Current networks suffer difficulties in locating the cause of network failures. Although network devices may issue many warnings while running, most of them are not sufficiently precise to be identified as errors. Some of them are early warnings that would not develop into real errors. Others are in effect random noise. During a major failure, many different devices will issue multiple warnings within a short time, causing overload for the NMS and the operators. However, for many scenarios, human experience is still vital to identify real issues and locate them. This situation may be improved by automatically associating warnings from multiple network devices together. Also, introducing automated learning techniques (comparing current warnings with historical relationships between warnings and actual faults) could increase the possibility and success rate of autonomic network diagnoses and troubleshooting. Depending on the network errors, some of them may always require human interventions, particularly for hardware failures. However, autonomic network management behavior may help to reduce the impact of errors, for example by switching traffic flows around. Today this is usually manual (except for classical routing updates). Fixing software failures and configuration errors currently depends on humans, and may even involve rolling back software versions and Jiang, et al. Expires April 5, 2015 [Page 9] Internet-Draft Autonomic Networking Gap Analysis October 2014 rebooting hardware. Such problems could be autonomically corrected if there were diagnostics and recovery functions defined in advance for them. This would fulfill the concept of self-healing. Another possible autonomic function is predicting device failures or overloads before they occur. A device could predict its own failure and warn its neighbors; or a device could predict its neighbor's failure. In either case, an autonomic network could respond as if the failure had already occurred by routing around the problem and reporting the failure, with no disturbance to users. The criteria for predicting failure could be temperature, battery status, bit error rates, etc. The criteria for predicting overload could be increasing load factor, latency, jitter, congestion loss, etc. 4. Features Needed by Autonomic Networks The task of autonomic networking is to build up individual autonomic processes that could properly combine to respond to every type of network event. Building on the preceding background information, and on the reference model in [I-D.irtf-nmrg-autonomic-network-definitions], this section will outline the gaps and missing features in general terms, and in some cases mentions general design principles that should apply. 4.1. More Coordination among Devices or Network Partitions Network services are dependent on a number of devices and parameters to be in place in a certain order. For example after a power failure a coordinated sequence of "return to normal" operations is desirable (e.g., switches and routers first, DNS servers second, etc.). Today, the correct sequence of events is either known only by a human administrator, or automated in a central script. In a truly autonomic network, elements should understand their dependencies, and be able to resolve them locally. In order to make right or good decisions autonomically, the network devices need to know more information than just reachability (routing) information from the relevant or neighbor devices. There are dependencies between such information and configurations, which devices must be able to derive for themselves. There are therefore increased requirements for horizontal information exchange in the networks. Particularly, three types of interaction among peer network devices are needed for autonomic decisions: discovery (to find neighbours and peers), synchronization (to agree on network status) and negotiation (when things need to be changed). Although there are many existing protocols with some discovery, syncronization or negotiation ability, each of them only serves a Jiang, et al. Expires April 5, 2015 [Page 10] Internet-Draft Autonomic Networking Gap Analysis October 2014 specific and narrow purpose. To avoid continued proliferation of such protocols, there is a need for reusable discovery, synchronization and negotiation mechanisms, which would support the discovery of many different types of device, the synchronization of many types of parameter and the negotiation of many different types of objective. 4.2. Reusable Common Components Elements of autonomic functions already exist today, within many different protocols. However, all such functions have their own discovery, transport, messaging and security mechanisms as well as non-autonomic management interfaces. Each protocol has its own version of the above-mentioned functions to serve specific and narrow purposes. It is often difficult to extend an existing protocol to serve different purposes. Therefore, in order to provide the reusable discovery, synchronization and negotiation mechanism mentioned above, it is desirable to develop a set of reusable common protocol components for Autonomic Networks. These components should be: o Able to identify other devices, users and processes securely. o Able to automatically secure operations, based on the above identity scheme. o Able to manage any type of information and information flows. o Able to discover peer devices and services for various autonomic service agents (or autonomic functions). o Able to support closed-loop operations when needed to provide self-managing functions involving more than one device. o Separable from the specific autonomic service agents (or autonomic functions). o Reusable by other autonomic functions. 4.3. Secure Control Plane The common components will in effect act as a control plane for autonomic operations, regardless whether they are implemented in-band as functions of the target network, in an overlay network, or even out-of-band in a separate network. Autonomic operations will be capable of changing how the network operates and allocating resources without human intervention or knowledge, so it is essential that they are secure. Therefore the control plane must be fully secure against Jiang, et al. Expires April 5, 2015 [Page 11] Internet-Draft Autonomic Networking Gap Analysis October 2014 forged autonomic operations and man-in-the middle attacks, and as secure as reasonably possible against denial of service attacks. It must be decided whether the control plane needs to be resistant to unwanted monitoring, i.e., whether encryption is required. 4.4. Less Configuration Most existing protocols have been defined to be as flexible as possible. Consequently, these protocols need many initial configurations to start operations. There are many choices and options that are unnecessary in any particular case. A large portion of these configurations target corner cases. Furthermore, in many protocols that already exist for years, some design considerations are no longer valid since the hardware technologies have made dramatic progress in recent years. There is much scope for simplifying the protocols and the operation of protocols. From another perspective, the deep reason why human decisions are often needed mainly result from the lack of information. When a device can collect enough information horizontally from other devices, it should be able to decide many parameters by itself, instead of receiving them from top-down configuration. It is desired that the top-down management is reduced in the Autonomic Networking. Ideally, only the abstract intent is needed from the human administrators. Neither users nor administrators should need to create and maintain detailed policies and profiles; if they are needed, they should be built autonomically. The local parameters should be decided by distributed Autonomic Nodes themselves, either from historic knowledge, analytics of current conditions, closed logical decision loops, or a combination of all. 4.5. Forecasting and Dry Runs In a conventional network, there is no mechanism for trying something out. That means that configuration changes have to be designed in the abstract and their probable effects have to be estimated theoretically. The only alternative to this would be to test them on a complete and realistic network simulator, which is unlikely to be possible for a network of any size. In any case, there is a risk that applying the changes to the running network will cause a failure of some kind. An autonomic network should fill this gap by supporting a "dry run" mode in which a configuration change could be tested out in the control plane without actually affecting the data plane. If the results are satisfactory, the change could be made live; if there is a problem, the change could be rolled back with no impact on users. Jiang, et al. Expires April 5, 2015 [Page 12] Internet-Draft Autonomic Networking Gap Analysis October 2014 4.6. Benefit from Knowledge The more knowledge we have, the more intelligent we are. It is the same for networks and network management. It is when one component in the network lacks knowledge that affects what it should do, and another component has that knowledge, that we usually rely on a human operator or a centralised management tool to convey the knowledge. Up to now, the only available network knowledge is usually the current network status inside a given device or relevant current status from other devices. However, historic knowledge is very helpful to make correct decisions, in particular to reduce network oscillation or to manage network resources over time. Transplantable knowledge from other networks can be helpful to initially set up a new network or new network devices. Knowledge of relationships between network events and network configuration may help a network to decide the best parameters according to real performance feedback. In addition to such historic knowledge, powerful data analytics of current network conditions may also be a valuable source of knowledge that can be exploited directly by autonomic nodes. 5. Security Considerations This document is focused on what is missing to allow autonomic network configuration, including of course security settings. Therefore, it does not itself create any new security issues. It is worth underlining that autonomic technology must be designed with strong security properties from the start, since a network with vulnerable autonomic functions would be at great risk. 6. IANA Considerations This memo includes no request to IANA. 7. Acknowledgements The authors would like to acknowledge the valuable comments made by participants in the IRTF Network Management Research Group. A review by Rene Struik was especially helpful. This document was produced using the xml2rfc tool [RFC2629]. Jiang, et al. Expires April 5, 2015 [Page 13] Internet-Draft Autonomic Networking Gap Analysis October 2014 8. Change log [RFC Editor: Please remove] draft-irtf-nmrg-an-gap-analysis-02: Review comments actioned, 2014-10-02. draft-irtf-nmrg-an-gap-analysis-01: RG comments added and more content in "Approach toward Autonomy" section, 2014-08-30. draft-irtf-nmrg-an-gap-analysis-00: RG comments added, 2014-04-02. draft-jiang-nmrg-an-gap-analysis-00: original version, 2014-02-14. 9. Informative References [I-D.behringer-default-secure] Behringer, M., Pritikin, M., and S. Bjarnason, "Making The Internet Secure By Default", draft-behringer-default- secure-00 (work in progress), January 2014. [I-D.irtf-nmrg-autonomic-network-definitions] Behringer, M., Pritikin, M., Bjarnason, S., Clemm, A., Carpenter, B., Jiang, S., and L. Ciavaglia, "Autonomic Networking - Definitions and Design Goals", draft-irtf- nmrg-autonomic-network-definitions-03 (work in progress), August 2014. [RFC1157] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple Network Management Protocol (SNMP)", STD 15, RFC 1157, May 1990. [RFC1661] Simpson, W., "The Point-to-Point Protocol (PPP)", STD 51, RFC 1661, July 1994. [RFC1994] Simpson, W., "PPP Challenge Handshake Authentication Protocol (CHAP)", RFC 1994, August 1996. [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. [RFC2136] Vixie, P., Thomson, S., Rekhter, Y., and J. Bound, "Dynamic Updates in the Domain Name System (DNS UPDATE)", RFC 2136, April 1997. [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, June 1999. Jiang, et al. Expires April 5, 2015 [Page 14] Internet-Draft Autonomic Networking Gap Analysis October 2014 [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, "Remote Authentication Dial In User Service (RADIUS)", RFC 2865, June 2000. [RFC2866] Rigney, C., "RADIUS Accounting", RFC 2866, June 2000. [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003. [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) version 6", RFC 3633, December 2003. [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, September 2007. [RFC5575] Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J., and D. McPherson, "Dissemination of Flow Specification Rules", RFC 5575, August 2009. [RFC5905] Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network Time Protocol Version 4: Protocol and Algorithms Specification", RFC 5905, June 2010. [RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J., and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, June 2011. Authors' Addresses Sheng Jiang Huawei Technologies Co., Ltd Q14, Huawei Campus, No.156 Beiqing Road Hai-Dian District, Beijing, 100095 P.R. China Email: jiangsheng@huawei.com Jiang, et al. Expires April 5, 2015 [Page 15] Internet-Draft Autonomic Networking Gap Analysis October 2014 Brian Carpenter Department of Computer Science University of Auckland PB 92019 Auckland 1142 New Zealand Email: brian.e.carpenter@gmail.com Michael H. Behringer Cisco Systems Building D, 45 Allee des Ormes Mougins 06250 France Email: mbehring@cisco.com Jiang, et al. Expires April 5, 2015 [Page 16]