--- 1/draft-ietf-i2rs-yang-dc-fabric-network-topology-03.txt 2018-01-09 23:13:29.444570137 -0800 +++ 2/draft-ietf-i2rs-yang-dc-fabric-network-topology-04.txt 2018-01-09 23:13:29.496571375 -0800 @@ -1,22 +1,22 @@ I2RS Working Group Y. Zhuang Internet-Draft D. Shi Intended status: Standards Track Huawei -Expires: June 25, 2018 R. Gu +Expires: July 13, 2018 R. Gu China Mobile H. Ananthakrishnan Packet Design - December 22, 2017 + January 9, 2018 - A YANG Data Model for Fabric Topology in Data Center Network - draft-ietf-i2rs-yang-dc-fabric-network-topology-03 + A YANG Data Model for Fabric Topology in Data Center Networks + draft-ietf-i2rs-yang-dc-fabric-network-topology-04 Abstract This document defines a YANG data model for fabric topology in Data Center Network. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. @@ -24,209 +24,182 @@ 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 https://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 June 25, 2018. + This Internet-Draft will expire on July 13, 2018. Copyright Notice - Copyright (c) 2017 IETF Trust and the persons identified as the + Copyright (c) 2018 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 (https://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 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Definitions an Acronyms . . . . . . . . . . . . . . . . . . . 3 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 - 2.2. Tree diagram . . . . . . . . . . . . . . . . . . . . . . 4 3. Model Overview . . . . . . . . . . . . . . . . . . . . . . . 4 3.1. Topology Model structure . . . . . . . . . . . . . . . . 4 - 3.2. Fabric Topology Model . . . . . . . . . . . . . . . . . . 5 + 3.2. Fabric Topology Model . . . . . . . . . . . . . . . . . . 4 3.2.1. Fabric Topology . . . . . . . . . . . . . . . . . . . 5 3.2.2. Fabric node extension . . . . . . . . . . . . . . . . 6 3.2.3. Fabric termination-point extension . . . . . . . . . 7 - 4. Fabric YANG Module . . . . . . . . . . . . . . . . . . . . . 8 - 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20 - 6. Security Considerations . . . . . . . . . . . . . . . . . . . 21 - 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22 - 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 22 - 8.1. Normative References . . . . . . . . . . . . . . . . . . 22 - 8.2. Informative References . . . . . . . . . . . . . . . . . 23 - Appendix A. Non NMDA -state modules . . . . . . . . . . . . . . 23 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 29 + 4. Fabric YANG Module . . . . . . . . . . . . . . . . . . . . . 7 + 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 + 6. Security Considerations . . . . . . . . . . . . . . . . . . . 20 + 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 21 + 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 21 + 8.1. Normative References . . . . . . . . . . . . . . . . . . 21 + 8.2. Informative References . . . . . . . . . . . . . . . . . 22 + Appendix A. Non NMDA -state modules . . . . . . . . . . . . . . 22 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 28 1. Introduction - Normally, a data center network is composed of single or multiple - fabrics which are also known as PODs (a Point Of Delivery). These - fabrics may be heterogeneous due to implementation of different - technologies while DC network upgrading or enrolling new techniques - and features. For example, Fabric A may use VXLAN while Fabric B may - use VLAN within a DC network. Likewise, a legacy Fabric may use - VXLAN while a new Fabric B implemented technique discussed in NVO3 WG - such as GPE[I-D. draft-ietf-nvo3-vxlan-gpe] may be built due to DC - expansion and upgrading. The configuration and management of such DC - networks with heterogeneous fabrics will be sophisticated and - complex. + Normally, a data center (DC) network is composed of single or + multiple fabrics which are also known as PODs (Points Of Delivery). + These fabrics may be heterogeneous due to implementation of different + technologies when a DC network is upgraded or new techniques and + features are enrolled. For example, Fabric A may use VXLAN while + Fabric B may use VLAN within a DC network. Likewise, an existing + fabric may use VXLAN while a new fabric, for example a fabric + introduced for DC upgrade and expansion, may implement a technique + discussed in NVO3 WG, such as GPE [I-D. draft-ietf-nvo3-vxlan-gpe]. + The configuration and management of such DC networks with + heterogeneous fabrics will result in considerable complexity, + requiring a fair amount of sophistication. Luckily, for a DC network, a fabric can be considered as an atomic - structure to provide network services and management, as well as - expand network capacity. From this point of view, the miscellaneous - DC network management can be decomposed to task of managing each - fabric respectively along with their connections, which can make the - entire management much concentrated and flexible, also easy to - expand. + structure for management purposes. From this point of view, the + management of the DC network can be decomposed into a set of tasks to + manage each fabric separately, as well as the fabric + interconnections. This way, the overall management task becomes very + flexible and makes it easy to expand and adopt to DC networks that + evolve over time. - With this purpose, this document defines a YANG data model for the - Fabric-based Data center topology by using YANG [6020][7950]. To do + As a basis for DC fabric management, this document defines a YANG + data model [6020][7950] for fabric-based data center topology. To do so, it augments the generic network and network topology data models - defined in [I-D.ietf-i2rs-yang-network-topo] with information - specific to Data Center fabric network. + defined in [I-D.ietf-i2rs-yang-network-topo] with information that is + specific to Data Center fabric networks. - This model defines the generic configuration and operational state - for a fabric-based network topology, which can be extended by vendors - with specific information. This model can then be used by a network - controller to represent its view of the fabric topology that it - controls and expose it to network administrators or applications for - DC network management. + The model defines the generic configuration and operational state for + a fabric-based network topology, which can subsequently be extended + by vendors with vendor-specific information as needed. The model can + be used by a network controller to represent its view of the fabric + topology that it controls and expose this view to network + administrators or applications for DC network management. - With the context of topology architecture defined in [I-D.ietf-i2rs- - yang-network-topo] and [I.D. draft-ietf-i2rs-usecase-reqs-summary], - this model can also be treated as an application of I2RS network - topology model [I-D.ietf-i2rs-yang-network-topo] in the scenario of - Data center network management. It can also act as a service - topology when mapping network elements at fabric layer to elements to - other topologies, such as L3 topology defined in [I.D. draft-ietf- - i2rs-yang-l3-topology-01. + Within the context of topology architecture defined in [I-D.ietf- + i2rs-yang-network-topo] and [I.D. draft-ietf-i2rs-usecase-reqs- + summary], this model can also be treated as an application of the + I2RS network topology model [I-D.ietf-i2rs-yang-network-topo] in the + scenario of Data center network management. It can also act as a + service topology when mapping network elements at the fabric layer to + elements of other topologies, such as L3 topologies as defined in + [I.D. draft-ietf-i2rs-yang-l3-topology]. - By using this fabric topology model, people can treat a fabric as an - entity and focus on characteristics of fabrics (such as encapsulation - type, gateway type, etc.) as well as their interconnections while - putting the underlay topology aside. As such, clients can consume - the topology information at fabric level, while no need to be aware - of entire set of links and nodes in underlay networks. The - configuration of a fabric topology can be made by a network - administractor to the controller by adding physical devices and links - of a fabric into a fabric network. Alternatively, the fabric - topology can also learnt from the underlay network infrastructure. + By using the fabric topology model defined in this document, people + can treat a fabric as a holistic entity and focus on characteristics + of a fabric (such as encapsulation type, gateway type, etc.) as well + as its connections to other fabrics while putting the underlay + topology aside. As such, clients can consume the topology + information at the fabric level with no need to be aware of the + entire set of links and nodes in the corresponding underlay networks. + A fabric topology can be configured by a network administrator using + the controller by adding physical devices and links into a fabric. + Alternatively, fabric topology can be learned from the underlay + network infrastructure. 2. Definitions an Acronyms 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 [RFC2119]. + document are to be interpreted as described in [RFC2119]. In this + document, these words will appear with that interpretation only when + in ALL CAPS. Lower case uses of these words are not to be + interpreted as carrying RFC-2119 significance. 2.1. Terminology - DC Fabric: also known as POD, is a module of network, compute, + Fabric: also known as a POD, is a module of network, compute, storage, and application components that work together to deliver - networking services. It is a repeatable design pattern, and its + networking services. It represents a repeatable design pattern. Its components maximize the modularity, scalability, and manageability of data centers. -2.2. Tree diagram - - The following notations are used within the data tree and carry the - meaning as below. - - Each node is printed as: - - - is one of: - + for current - x for deprecated - o for obsolete - is one of: - rw for configuration data - ro for non-configuration data - -x for rpcs - -n for notifications - is the name of the node - - If the node is augmented into the tree from another module, its name - is printed as :. - is one of: - ? for an optional leaf or choice - ! for a presence container - * for a leaf-list or list - [] for a list's keys - is the name of the type for leafs and leaf-lists - - In this document, these words will appear with that interpretation - only when in ALL CAPS. Lower case uses of these words are not to be - interpreted as carrying RFC-2119 significance. - 3. Model Overview - This section provides an overview of the DC Fabric topology model and - its relationship with other topology models. + This section provides an overview of the data center fabric topology + model and its relationship with other topology models. 3.1. Topology Model structure The relationship of the DC fabric topology model and other topology - models is shown in the following figure (dotted lines in the figure - denote augmentations). + models is shown in the following figure. +------------------------+ | network model | +------------------------+ | | +------------V-----------+ | network topology model | +------------------------+ | +-----------+-----+------+-------------+ | | | | +---V----+ +---V----+ +---V----+ +----V---+ | L1 | | L2 | | L3 | | Fabric | |topology| |topology| |topology| |topology| | model | | model | | model | | model | +--------+ +--------+ +--------+ +--------+ + Figure 1: The network data model structure From the perspective of resource management and service provisioning - for a Data Center network, the fabric topology model augments the + for a data center network, the fabric topology model augments the basic network topology model with definitions and features specific to a DC fabric, to provide common configuration and operations for heterogeneous fabrics. 3.2. Fabric Topology Model The fabric topology model module is designed to be generic and can be applied to data center fabrics built with different technologies, such as VLAN, VXLAN etc. The main purpose of this module is to - configure and manage fabrics and their connections. provide a fabric- - based topology view for data center network applications. + configure and manage fabrics and their connections. It provides a + fabric-based topology view for data center applications. 3.2.1. Fabric Topology - In the fabric topology module, a fabric is modeled as a node in the - network, while the fabric-based Data center network consists of a set - of fabric nodes and their connections known as "fabric port". The - following is the snip of the definition to show the main structure of - the model: + In the fabric topology module, a fabric is modeled as a node of a + network, as such the fabric-based data center network consists of a + set of fabric nodes and their connections. The following depicts a + snippet of the definitions to show the main structure of the model. + The notation syntax follows [I-D.draft-ietf-netmod-yang-tree- + diagrams]. module: ietf-fabric-topology augment /nw:networks/nw:network/nw:network-types: +--rw fabric-network! augment /nw:networks/nw:network/nw:node: +--rw fabric-attributes +--rw fabric-id? fabric-id +--rw name? string +--rw type? fabrictype:underlay-network-type +--rw description? string @@ -238,39 +211,40 @@ +--ro role? fabric-port-role +--ro type? fabric-port-type The fabric topology module augments the generic ietf-network and ietf-network-topology modules as follows: o A new topology type "ietf-fabric-topology" is introduced and added under the "network-types" container of the ietf-network module. o Fabric is defined as a node under the network/node container. A - new container of "fabric-attributes" is defined to carry - attributes for a fabric network such as gateway mode, fabric - types, involved device nodes and links etc. + new container "fabric-attributes" is defined to carry attributes + for a fabric such as gateway mode, fabric types, involved device + nodes, and links. o Termination points (in network topology module) are augmented with fabric port attributes defined in a container. The "termination- - point" here can represent the "port" of a fabric that provides - connections to other nodes, such as device internally, another - fabric externally and also end hosts. + point" here is used to represent a fabric "port" that provides + connections to other nodes, such as an internal device, another + fabric externally, or end hosts. - Details of fabric node and fabric termination point extension will be - explained in the following sections. + Details of the fabric node and the fabric termination point extension + will be explained in the following sections. 3.2.2. Fabric node extension - As a network, a fabric itself is composed of set of network elements - i.e. devices, and related links. As stated previously, the - configuration of a fabric is contained under the "fabric-attributes" - container depicted as follows: + As an atomic network, a fabric itself is composed of a set of network + elements i.e. devices, and related links. The configuration of a + fabric is contained under the "fabric-attributes" container depicted + as follows. The notation syntax follows [I-D.draft-ietf-netmod-yang- + tree-diagrams]. +--rw fabric-attributes +--rw fabric-id? fabric-id +--rw name? string +--rw type? fabrictype:underlay-network-type +--rw vni-capacity | +--rw min? int32 | +--rw max? int32 +--rw description? string +--rw options @@ -280,91 +254,84 @@ +--rw device-nodes* [device-ref] | +--rw device-ref fabrictype:node-ref | +--rw role? fabrictype:device-role +--rw device-links* [link-ref] | +--rw link-ref fabrictype:link-ref +--rw device-ports* [port-ref] +--rw port-ref fabrictype:tp-ref +--rw port-type? fabrictypes:port-type +--rw bandwidth? fabrictypes:bandwidth - As in the module, additional data objects for nodes are introduced by - augmenting the "node" list of the network module. New objects - include fabric name, type of the fabric, descriptions of the fabric - as well as a set of options defined in an "options" container. The - options container includes type of the gateway-mode (centralized or - distributed) and traffic-behavior (whether acl needed for the - traffic). - - Also, it defines a list of device-nodes and related links as - supporting-nodes to form a fabric network. These device nodes and - links are leaf-ref of existing nodes and links in the underlay - topology. For the device-node, the "role" object is defined to - represents the role of the device within the fabric, such as "SPINE" - or "LEAF", which should work together with gateway-mode. + In the module, additional data objects for fabric nodes are + introduced by augmenting the "node" list of the network module. New + objects include fabric name, type of the fabric, descriptions of the + fabric as well as a set of options defined in an "options" container. + The "options" container includes the gateway-mode type (centralized + or distributed) and traffic-behavior (whether an Access Control Lists + (ACLs) is needed for the traffic). Also, it includes a list of + device-nodes and related links as supporting-nodes to form a fabric + network. These device nodes and links are represented as leaf-refs + of existing nodes and links in the underlay topology. For the + device-node, the "role" object is defined to represent the role of a + device within the fabric, such as "SPINE" or "LEAF", which should + work together with the gateway-mode. 3.2.3. Fabric termination-point extension - Since the fabric can be considered as a node, in this concept, - "termination-points" can represent "ports" of a fabric that connects - to other fabrics or end hosts, besides representing ports that - connect devices inside the fabric itself. + Since a fabric can be considered as a node, "termination-points" can + represent fabric "ports" that connect to other fabrics, end hosts, as + well as devices inside the fabric. - As such, the "termination-point" in the fabric topology has three - roles, that are internal TP that connects to devices within a fabric, - external TP that connects to outside network, and access TP to end - hosts. + As such, the set of "termination-points" of a fabric indicate all + connections of the fabric, including its internal connections, + interconnections with other fabrics, and connections to end hosts. - The set of "termination-point" of a fabric indicates all connections - of the fabric, including its internal connections, interconnections - with other fabrics and also connections to end hosts for a DC - network. + The structure of fabric ports is as follows. The notation syntax + follows [I-D.draft-ietf-netmod-yang-tree-diagrams]. The structure of fabric ports is as follows: augment /nw:networks/nw:network/nw:node/nt:termination-point: +--ro fport-attributes +--ro name? string +--ro role? fabric-port-role +--ro type? fabric-port-type +--ro device-port? tp-ref +--ro (tunnel-option)? It augments the termination points (in network topology module) with fabric port attributes defined in a container. - New nodes are defined for fabric ports which include name, role of + New nodes are defined for fabric ports including fabric name, role of the port within the fabric (internal port, external port to outside network, access port to end hosts), port type (l2 interface, l3 - interface etc). By defining the device-port as a tp-ref, a fabric + interface, etc). By defining the device-port as a tp-ref, a fabric port can be mapped to a device node in the underlay network. Also, a new container for tunnel-options is introduced to present the - tunnel configuration on the port. + tunnel configuration on a port. - The termination points information are all learnt from the underlay - networks but not configured by the fabric topology layer. + The termination point information is learned from the underlay + networks, not configured by the fabric topology layer. 4. Fabric YANG Module file "ietf-dc-fabric-types@2017-12-21.yang" module ietf-dc-fabric-types { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-dc-fabric-types"; prefix fabrictypes; - organization "IETF I2RS (Interface to the Routing System) Working Group"; contact - "WG Web: WG List: Editor: Yan Zhuang Editor: Danian Shi "; description @@ -957,43 +921,44 @@ The YANG module defined in this document is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC5246]. The NETCONF access control model [RFC6536] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol - operations and content.These are the subtrees and data nodes and - their sensitivity/vulnerability in the ietf-dc-fabric-topology - module: + operations and content. The subtrees and data nodes and their + sensitivity/vulnerability in the ietf-dc-fabric-topology module are + as follows: fabric-attributes: A malicious client could attempt to sabotage the - configuration of important fabric attributes, such as device-nodes, + configuration of important fabric attributes, such as device-nodes or type. Some of the readable data nodes in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or - notification) to these data nodes. These are the subtrees and data - nodes and their sensitivity/vulnerability in the ietf-dc-fabric- - topology module: + notification) to these data nodes. The subtrees and data nodes and + their sensitivity/vulnerability in the ietf-dc-fabric-topology module + are as follows: fport-attributes: A malicious client could attempt to read the connections of fabrics without permission, such as device-port, name. 7. Acknowledgements We wish to acknowledge the helpful contributions, comments, and - suggestions that were received from Alexander Clemm, Xufeng Liu, - Susan Hares, Wei Song, Luis M. Contreras and Benoit Claise. + suggestions that were received from Alexander Clemm, Donald E. + Eastlake, Xufeng Liu, Susan Hares, Wei Song, Luis M. Contreras and + Benoit Claise. 8. References 8.1. Normative References [I-D.draft-ietf-i2rs-yang-l3-topology] Clemm, A., Medved, J., Tkacik, T., Liu, X., Bryskin, I., Guo, A., Ananthakrishnan, H., Bahadur, N., and V. Beeram, "A YANG Data Model for Layer 3 Topologies", I-D draft- ietf-i2rs-yang-l3-topology-04, September 2016. @@ -1047,22 +1012,26 @@ RFC 7950, DOI 10.17487/RFC7950, Auguest 2016. [RFC8040] Bierman, A., Bjorklund, B., and K. Watsen, "RESTCONF Protocol", Jan 2017, . 8.2. Informative References [I-D.draft-ietf-i2rs-usecase-reqs-summary] Hares, S. and M. Chen, "Summary of I2RS Use Case - Requirements", I-D draft-ietf-i2rs-usecase-reqs-summary- - 01, May 2015. + Requirements", I-D draft-ietf-netmod-yang-tree-diagrams, + May 2015. + + [I-D.draft-ietf-netmod-yang-tree-diagrams] + Bjorklund, M. and L. Berger, "YANG Tree Diagrams", I-D + draft-ietf-netmod-yang-tree-diagrams, October 2017. Appendix A. Non NMDA -state modules The YANG module ietf-fabric-toplogy defined in this document augments two modules, ietf-network and ietf-network-topology, that are designed to be used in conjunction with implementations that support the Network Management Datastore Architecture (NMDA) defined in [I- D.draft-ietf-netmod-revised-datastores]. In order to allow implementations to use the model even in case when NMDA is not supported, a set of companion modules have been defined that