Network Working Group M. Bjorklund Internet-Draft Tail-f Systems Intended status: Standards Track February 6, 2013 Expires: August 10, 2013 A YANG Data Model for Interface Management draft-ietf-netmod-interfaces-cfg-09 Abstract This document defines a YANG data model for the management of network interfaces. It is expected that interface type specific data models augment the generic interfaces data model defined in this document. 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 10, 2013. Copyright Notice Copyright (c) 2013 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 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Bjorklund Expires August 10, 2013 [Page 1] Internet-Draft YANG Interface Management February 2013 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2. Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Interfaces Data Model . . . . . . . . . . . . . . . . . . . . 5 3.1. The interface List . . . . . . . . . . . . . . . . . . . . 5 3.2. Interface References . . . . . . . . . . . . . . . . . . . 6 3.3. Interface Layering . . . . . . . . . . . . . . . . . . . . 6 4. Relationship to the IF-MIB . . . . . . . . . . . . . . . . . . 8 5. Interfaces YANG Module . . . . . . . . . . . . . . . . . . . . 10 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23 7. Security Considerations . . . . . . . . . . . . . . . . . . . 24 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 25 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 26 9.1. Normative References . . . . . . . . . . . . . . . . . . . 26 9.2. Informative References . . . . . . . . . . . . . . . . . . 26 Appendix A. Example: Ethernet Interface Module . . . . . . . . . 27 Appendix B. Example: Ethernet Bonding Interface Module . . . . . 29 Appendix C. Example: VLAN Interface Module . . . . . . . . . . . 30 Appendix D. Example: NETCONF reply . . . . . . . . . . . . 31 Appendix E. Examples: Interface Naming Schemes . . . . . . . . . 32 E.1. Router with Restricted Interface Names . . . . . . . . . . 32 E.2. Router with Arbitrary Interface Names . . . . . . . . . . 33 E.3. Ethernet Switch with Restricted Interface Names . . . . . 33 E.4. Generic Host with Restricted Interface Names . . . . . . . 34 E.5. Generic Host with Arbitrary Interface Names . . . . . . . 35 Appendix F. ChangeLog . . . . . . . . . . . . . . . . . . . . . . 36 F.1. Version -08 . . . . . . . . . . . . . . . . . . . . . . . 36 F.2. Version -07 . . . . . . . . . . . . . . . . . . . . . . . 36 F.3. Version -06 . . . . . . . . . . . . . . . . . . . . . . . 36 F.4. Version -05 . . . . . . . . . . . . . . . . . . . . . . . 36 F.5. Version -04 . . . . . . . . . . . . . . . . . . . . . . . 36 F.6. Version -03 . . . . . . . . . . . . . . . . . . . . . . . 36 F.7. Version -02 . . . . . . . . . . . . . . . . . . . . . . . 37 F.8. Version -01 . . . . . . . . . . . . . . . . . . . . . . . 37 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 38 Bjorklund Expires August 10, 2013 [Page 2] Internet-Draft YANG Interface Management February 2013 1. Introduction This document defines a YANG [RFC6020] data model for the management of network interfaces. It is expected that interface type specific data models augment the generic interfaces data model defined in this document. Network interfaces are central to the management of many Internet protocols. Thus, it is important to establish a common data model for how interfaces are identified and configured. 1.1. Terminology The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14, [RFC2119]. The following terms are defined in [RFC6241] and are not redefined here: o client o server The following terms are defined in [RFC6020] and are not redefined here: o augment o data model o data node Bjorklund Expires August 10, 2013 [Page 3] Internet-Draft YANG Interface Management February 2013 2. Objectives This section describes some of the design objectives for the model presented in Section 5. o It is recognized that existing implementations will have to map the interface data model defined in this memo to their proprietary native data model. The new data model should be simple to facilitate such mappings. o The data model should be suitable for new implementations to use as-is, without requiring a mapping to a different native model. o References to interfaces should be as simple as possible, preferably by using a single leafref. o The mapping to ifIndex [RFC2863] used by SNMP to identify interfaces must be clear. o The model must support interface layering, both simple layering where one interface is layered on top of exactly one other interface, and more complex scenarios where one interface is aggregated over N other interfaces, or when N interfaces are multiplexed over one other interface. o The data model should support the pre-provisioning of interface configuration, i.e., it should be possible to configure an interface whose physical interface hardware is not present on the device. It is recommended that devices that support dynamic addition and removal of physical interfaces also support pre- provisioning. Bjorklund Expires August 10, 2013 [Page 4] Internet-Draft YANG Interface Management February 2013 3. Interfaces Data Model The data model in the module "ietf-interfaces" has the following structure, where square brackets are used to enclose a list's keys, "?" means that the leaf is optional, and "*" denotes a leaf-list: +--rw interfaces +--rw interface [name] +--rw name string +--rw description? string +--rw type ianaift:iana-if-type +--rw location? string +--rw enabled? boolean +--ro oper-status? enumeration +--ro last-change? yang:date-and-time +--ro if-index? int32 +--rw link-up-down-trap-enable? enumeration +--ro phys-address? yang:phys-address +--ro higher-layer-if* interface-ref +--ro lower-layer-if* interface-ref +--ro speed? yang:gauge64 +--ro statistics +--ro discontinuity-time? yang:date-and-time +--ro in-octets? yang:counter64 +--ro in-unicast-pkts? yang:counter64 +--ro in-broadcast-pkts? yang:counter64 +--ro in-multicast-pkts? yang:counter64 +--ro in-discards? yang:counter32 +--ro in-errors? yang:counter32 +--ro in-unknown-protos? yang:counter32 +--ro out-octets? yang:counter64 +--ro out-unicast-pkts? yang:counter64 +--ro out-broadcast-pkts? yang:counter64 +--ro out-multicast-pkts? yang:counter64 +--ro out-discards? yang:counter32 +--ro out-errors? yang:counter32 3.1. The interface List The data model for interfaces presented in this document uses a flat list of interfaces. Each interface in the list is identified by its name. Furthermore, each interface has a mandatory "type" leaf, and a "location" leaf. The combination of "type" and "location" is unique within the interface list. It is expected that interface type specific data models augment the interface list, and use the "type" leaf to make the augmentation conditional. Bjorklund Expires August 10, 2013 [Page 5] Internet-Draft YANG Interface Management February 2013 As an example of such an interface type specific augmentation, consider this YANG snippet. For a more complete example, see Appendix A. import interfaces { prefix "if"; } augment "/if:interfaces/if:interface" { when "if:type = 'ethernetCsmacd'"; container ethernet { leaf duplex { ... } } } The "location" leaf is a string. It is optional in the data model, but if the type represents a physical interface, it is mandatory. The format of this string is device- and type-dependent. The device uses the location string to identify the physical or logical entity that the configuration applies to. For example, if a device has a single array of 8 ethernet ports, the location can be one of the strings "1" to "8". As another example, if a device has N cards of M ports, the location can be on the form "n/m", such as "1/0". How a client can learn which types and locations are present on a certain device is outside the scope of this document. 3.2. Interface References An interface is identified by its name, which is unique within the server. This property is captured in the "interface-ref" typedef, which other YANG modules SHOULD use when they need to reference an existing interface. 3.3. Interface Layering There is no generic mechanism for how an interface is configured to be layered on top of some other interface. It is expected that interface type specific models define their own data nodes for interface layering, by using "interface-ref" types to reference lower layers. Below is an example of a model with such nodes. For a more complete example, see Appendix B. Bjorklund Expires August 10, 2013 [Page 6] Internet-Draft YANG Interface Management February 2013 import interfaces { prefix "if"; } augment "/if:interfaces/if:interface" { when "if:type = 'ieee8023adLag'"; leaf-list slave-if { type if:interface-ref; must "/if:interfaces/if:interface[if:name = current()]" + "/if:type = 'ethernetCsmacd'" { description "The type of a slave interface must be ethernet"; } } // other bonding config params, failover times etc. } Two state data leaf-lists, "higher-layer-if" and "lower-layer-if", represent a read-only view of the interface layering hierarchy. Bjorklund Expires August 10, 2013 [Page 7] Internet-Draft YANG Interface Management February 2013 4. Relationship to the IF-MIB If the device implements IF-MIB [RFC2863], each entry in the "interface" list is typically mapped to one ifEntry. The "if-index" leaf contains the value of the corresponding ifEntry's ifIndex. In most cases, the "name" of an "interface" entry is mapped to ifName. ifName is defined as an DisplayString [RFC2579] which uses a 7-bit ASCII character set. An implementation MAY restrict the allowed values for "name" to match the restrictions of ifName. The IF-MIB allows two different ifEntries to have the same ifName. Devices that support this feature, and also support the configuration of these interfaces using the "interface" list, cannot have a 1-1 mapping between the "name" leaf and ifName. The IF-MIB also defines the writable object ifPromiscuousMode. Since this object typically is not a configuration object, it is not mapped to the "ietf-interfaces" module. The following table lists the YANG data nodes with corresponding objects in the IF-MIB. Bjorklund Expires August 10, 2013 [Page 8] Internet-Draft YANG Interface Management February 2013 +----------------------------------+------------------------+ | YANG data node | IF-MIB object | +----------------------------------+------------------------+ | interface | ifEntry | | name | ifName | | description | ifAlias | | type | ifType | | enabled | ifAdminStatus | | oper-status | ifOperStatus | | last-change | ifLastChange | | if-index | ifIndex | | link-up-down-trap-enable | ifLinkUpDownTrapEnable | | phys-address | ifPhysAddress | | higher-layer-if / lower-layer-if | ifStackTable | | speed | ifSpeed | | in-octets | ifHCInOctets | | in-unicast-pkts | ifHCInUcastPkts | | in-broadcast-pkts | ifHCInBroadcastPkts | | in-multicast-pkts | ifHCInMulticastPkts | | in-discards | ifInDiscards | | in-errors | ifInErrors | | in-unknown-protos | ifInUnknownProtos | | out-octets | ifHCOutOctets | | out-unicast-pkts | ifHCOutUcastPkts | | out-broadcast-pkts | ifHCOutBroadcastPkts | | out-multicast-pkts | ifHCOutMulticastPkts | | out-discards | ifOutDiscards | | out-errors | ifOutErrors | +----------------------------------+------------------------+ Mapping of YANG data nodes to IF-MIB objects Bjorklund Expires August 10, 2013 [Page 9] Internet-Draft YANG Interface Management February 2013 5. Interfaces YANG Module This YANG module imports a typedef from [I-D.ietf-netmod-iana-if-type]. RFC Ed.: update the date below with the date of RFC publication and remove this note. file "ietf-interfaces@2013-02-06.yang" module ietf-interfaces { namespace "urn:ietf:params:xml:ns:yang:ietf-interfaces"; prefix if; import ietf-yang-types { prefix yang; } import iana-if-type { prefix ianaift; } organization "IETF NETMOD (NETCONF Data Modeling Language) Working Group"; contact "WG Web: WG List: WG Chair: David Kessens WG Chair: Juergen Schoenwaelder Editor: Martin Bjorklund "; description "This module contains a collection of YANG definitions for managing network interfaces. Copyright (c) 2012 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License Bjorklund Expires August 10, 2013 [Page 10] Internet-Draft YANG Interface Management February 2013 set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; // RFC Ed.: replace XXXX with actual RFC number and remove this // note. // RFC Ed.: update the date below with the date of RFC publication // and remove this note. revision 2013-02-06 { description "Initial revision."; reference "RFC XXXX: A YANG Data Model for Interface Management"; } /* Typedefs */ typedef interface-ref { type leafref { path "/if:interfaces/if:interface/if:name"; } description "This type is used by data models that need to reference interfaces."; } /* Features */ feature arbitrary-names { description "This feature indicates that the server allows interfaces to be named arbitrarily."; } feature if-mib { description "This feature indicates that the server implements IF-MIB."; reference "RFC 2863: The Interfaces Group MIB"; } /* Data nodes */ container interfaces { Bjorklund Expires August 10, 2013 [Page 11] Internet-Draft YANG Interface Management February 2013 description "Interface parameters."; list interface { key "name"; unique "type location"; description "The list of interfaces on the device."; leaf name { type string; description "The name of the interface. A device MAY restrict the allowed values for this leaf, possibly depending on the type and location. If the device allows arbitrarily named interfaces, the feature 'arbitrary-names' is advertised. This leaf MAY be mapped to ifName by an implementation. Such an implementation MAY restrict the allowed values for this leaf so that it matches the restrictions of ifName. If a NETCONF server that implements this restriction is sent a value that doesn't match the restriction, it MUST reply with an rpc-error with the error-tag 'invalid-value'."; reference "RFC 2863: The Interfaces Group MIB - ifName"; } leaf description { type string; description "A textual description of the interface. This leaf MAY be mapped to ifAlias by an implementation. Such an implementation MAY restrict the allowed values for this leaf so that it matches the restrictions of ifAlias. If a NETCONF server that implements this restriction is sent a value that doesn't match the restriction, it MUST reply with an rpc-error with the error-tag 'invalid-value'."; reference "RFC 2863: The Interfaces Group MIB - ifAlias"; } Bjorklund Expires August 10, 2013 [Page 12] Internet-Draft YANG Interface Management February 2013 leaf type { type ianaift:iana-if-type; mandatory true; description "The type of the interface. When an interface entry is created, a server MAY initialize the type leaf with a valid value, e.g., if it is possible to derive the type from the name of the interface."; reference "RFC 2863: The Interfaces Group MIB - ifType"; } leaf location { type string; description "The device-specific location of the interface of a particular type. The format of the location string depends on the interface type and the device. If a NETCONF server is sent a value that doesn't match this format, it MUST reply with an rpc-error with the error-tag 'invalid-value'. If the interface's type represents a physical interface, this leaf MUST be set. When an interface entry is created, a server MAY initialize the location leaf with a valid value, e.g., if it is possible to derive the location from the name of the interface."; } leaf enabled { type boolean; default "true"; description "The desired state of the interface. This leaf contains the configured, desired state of the interface. Systems that implement the IF-MIB use the value of this leaf to set IF-MIB.ifAdminStatus to 'up' or 'down' after an ifEntry has been initialized, as described in RFC 2863."; reference "RFC 2863: The Interfaces Group MIB - ifAdminStatus"; } Bjorklund Expires August 10, 2013 [Page 13] Internet-Draft YANG Interface Management February 2013 leaf oper-status { type enumeration { enum up { value 1; description "Ready to pass packets."; } enum down { value 2; description "The interface does not pass any packets."; } enum testing { value 3; description "In some test mode. No operational packets can be passed."; } enum unknown { value 4; description "Status cannot be determined for some reason."; } enum dormant { value 5; description "Waiting for some external event."; } enum not-present { value 6; description "Some component (typically hardware) is missing."; } enum lower-layer-down { value 7; description "Down due to state of lower-layer interface(s)."; } } config false; description "The current operational state of the interface. If 'enabled' is 'false' then 'oper-status' should be 'down'. If 'enabled' is changed to 'true' then 'oper-status' should change to 'up' if the interface is ready to transmit and receive network traffic; it should change to 'dormant' if the interface is waiting for Bjorklund Expires August 10, 2013 [Page 14] Internet-Draft YANG Interface Management February 2013 external actions (such as a serial line waiting for an incoming connection); it should remain in the 'down' state if and only if there is a fault that prevents it from going to the 'up' state; it should remain in the 'not-present' state if the interface has missing (typically, hardware) components."; reference "RFC 2863: The Interfaces Group MIB - ifOperStatus"; } leaf last-change { type yang:date-and-time; config false; description "The time the interface entered its current operational state. If the current state was entered prior to the last re-initialization of the local network management subsystem, then this node is not present."; reference "RFC 2863: The Interfaces Group MIB - ifLastChange"; } leaf if-index { if-feature if-mib; type int32 { range "1..2147483647"; } config false; description "The ifIndex value for the ifEntry represented by this interface. Media-specific modules must specify how the type is mapped to entries in the ifTable."; reference "RFC 2863: The Interfaces Group MIB - ifIndex"; } leaf link-up-down-trap-enable { if-feature if-mib; type enumeration { enum enabled { value 1; } enum disabled { value 2; } } Bjorklund Expires August 10, 2013 [Page 15] Internet-Draft YANG Interface Management February 2013 description "Indicates whether linkUp/linkDown SNMP notifications should be generated for this interface. If this node is not configured, the value 'enabled' is operationally used by the server for interfaces which do not operate on top of any other interface (i.e., there are no 'lower-layer-if' entries), and 'disabled' otherwise."; reference "RFC 2863: The Interfaces Group MIB - ifLinkUpDownTrapEnable"; } leaf phys-address { type yang:phys-address; config false; description "The interface's address at its protocol sub-layer. For example, for an 802.x interface, this object normally contains a MAC address. The interface's media-specific modules must define the bit and byte ordering and the format of the value of this object. For interfaces that do not have such an address (e.g., a serial line), this node is not present."; reference "RFC 2863: The Interfaces Group MIB - ifPhysAddress"; } leaf-list higher-layer-if { type interface-ref; config false; description "A list of references to interfaces layered on top of this interface."; reference "RFC 2863: The Interfaces Group MIB - ifStackTable"; } leaf-list lower-layer-if { type interface-ref; config false; description "A list of references to interfaces layered underneath this interface."; reference "RFC 2863: The Interfaces Group MIB - ifStackTable"; } Bjorklund Expires August 10, 2013 [Page 16] Internet-Draft YANG Interface Management February 2013 leaf speed { type yang:gauge64; units "bits / second"; config false; description "An estimate of the interface's current bandwidth in bits per second. For interfaces which do not vary in bandwidth or for those where no accurate estimation can be made, this node should contain the nominal bandwidth. For interfaces that has no concept of bandwidth, this node is not present."; reference "RFC 2863: The Interfaces Group MIB - ifSpeed, ifHighSpeed"; } container statistics { config false; description "A collection of interface-related statistics objects."; leaf discontinuity-time { type yang:date-and-time; description "The time on the most recent occasion at which any one or more of this interface's counters suffered a discontinuity. If no such discontinuities have occurred since the last re-initialization of the local management subsystem, then this node contains the time the local management subsystem re-initialized itself."; } leaf in-octets { type yang:counter64; description "The total number of octets received on the interface, including framing characters. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of 'discontinuity-time'."; reference "RFC 2863: The Interfaces Group MIB - ifHCInOctets"; } leaf in-unicast-pkts { type yang:counter64; description Bjorklund Expires August 10, 2013 [Page 17] Internet-Draft YANG Interface Management February 2013 "The number of packets, delivered by this sub-layer to a higher (sub-)layer, which were not addressed to a multicast or broadcast address at this sub-layer. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of 'discontinuity-time'."; reference "RFC 2863: The Interfaces Group MIB - ifHCInUcastPkts"; } leaf in-broadcast-pkts { type yang:counter64; description "The number of packets, delivered by this sub-layer to a higher (sub-)layer, which were addressed to a broadcast address at this sub-layer. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of 'discontinuity-time'."; reference "RFC 2863: The Interfaces Group MIB - ifHCInBroadcastPkts"; } leaf in-multicast-pkts { type yang:counter64; description "The number of packets, delivered by this sub-layer to a higher (sub-)layer, which were addressed to a multicast address at this sub-layer. For a MAC layer protocol, this includes both Group and Functional addresses. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of 'discontinuity-time'."; reference "RFC 2863: The Interfaces Group MIB - ifHCInMulticastPkts"; } leaf in-discards { type yang:counter32; description "The number of inbound packets which were chosen to be discarded even though no errors had been detected to prevent their being deliverable to a higher-layer Bjorklund Expires August 10, 2013 [Page 18] Internet-Draft YANG Interface Management February 2013 protocol. One possible reason for discarding such a packet could be to free up buffer space. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of 'discontinuity-time'."; reference "RFC 2863: The Interfaces Group MIB - ifInDiscards"; } leaf in-errors { type yang:counter32; description "For packet-oriented interfaces, the number of inbound packets that contained errors preventing them from being deliverable to a higher-layer protocol. For character- oriented or fixed-length interfaces, the number of inbound transmission units that contained errors preventing them from being deliverable to a higher-layer protocol. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of 'discontinuity-time'."; reference "RFC 2863: The Interfaces Group MIB - ifInErrors"; } leaf in-unknown-protos { type yang:counter32; description "For packet-oriented interfaces, the number of packets received via the interface which were discarded because of an unknown or unsupported protocol. For character-oriented or fixed-length interfaces that support protocol multiplexing the number of transmission units received via the interface which were discarded because of an unknown or unsupported protocol. For any interface that does not support protocol multiplexing, this counter is not present. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of 'discontinuity-time'."; reference "RFC 2863: The Interfaces Group MIB - ifInUnknownProtos"; } Bjorklund Expires August 10, 2013 [Page 19] Internet-Draft YANG Interface Management February 2013 leaf out-octets { type yang:counter64; description "The total number of octets transmitted out of the interface, including framing characters. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of 'discontinuity-time'."; reference "RFC 2863: The Interfaces Group MIB - ifHCOutOctets"; } leaf out-unicast-pkts { type yang:counter64; description "The total number of packets that higher-level protocols requested be transmitted, and which were not addressed to a multicast or broadcast address at this sub-layer, including those that were discarded or not sent. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of 'discontinuity-time'."; reference "RFC 2863: The Interfaces Group MIB - ifHCOutUcastPkts"; } leaf out-broadcast-pkts { type yang:counter64; description "The total number of packets that higher-level protocols requested be transmitted, and which were addressed to a broadcast address at this sub-layer, including those that were discarded or not sent. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of 'discontinuity-time'."; reference "RFC 2863: The Interfaces Group MIB - ifHCOutBroadcastPkts"; } leaf out-multicast-pkts { type yang:counter64; description "The total number of packets that higher-level protocols Bjorklund Expires August 10, 2013 [Page 20] Internet-Draft YANG Interface Management February 2013 requested be transmitted, and which were addressed to a multicast address at this sub-layer, including those that were discarded or not sent. For a MAC layer protocol, this includes both Group and Functional addresses. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of 'discontinuity-time'."; reference "RFC 2863: The Interfaces Group MIB - ifHCOutMulticastPkts"; } leaf out-discards { type yang:counter32; description "The number of outbound packets which were chosen to be discarded even though no errors had been detected to prevent their being transmitted. One possible reason for discarding such a packet could be to free up buffer space. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of 'discontinuity-time'."; reference "RFC 2863: The Interfaces Group MIB - ifOutDiscards"; } leaf out-errors { type yang:counter32; description "For packet-oriented interfaces, the number of outbound packets that could not be transmitted because of errors. For character-oriented or fixed-length interfaces, the number of outbound transmission units that could not be transmitted because of errors. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of 'discontinuity-time'."; reference "RFC 2863: The Interfaces Group MIB - ifOutErrors"; } } } Bjorklund Expires August 10, 2013 [Page 21] Internet-Draft YANG Interface Management February 2013 } } Bjorklund Expires August 10, 2013 [Page 22] Internet-Draft YANG Interface Management February 2013 6. IANA Considerations This document registers a URI in the IETF XML registry [RFC3688]. Following the format in RFC 3688, the following registration is requested to be made. URI: urn:ietf:params:xml:ns:yang:ietf-interfaces Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. This document registers a YANG module in the YANG Module Names registry [RFC6020]. name: ietf-interfaces namespace: urn:ietf:params:xml:ns:yang:ietf-interfaces prefix: if reference: RFC XXXX Bjorklund Expires August 10, 2013 [Page 23] Internet-Draft YANG Interface Management February 2013 7. Security Considerations The YANG module defined in this memo is designed to be accessed via the NETCONF protocol [RFC6241]. The lowest NETCONF layer is the secure transport layer and the mandatory-to-implement secure transport is SSH [RFC6242]. There are a number of data nodes defined in the YANG module which are writable/creatable/deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g., ) to these data nodes without proper protection can have a negative effect on network operations. These are the subtrees and data nodes and their sensitivity/vulnerability: /interfaces/interface: This list specifies the configured interfaces on a device. Unauthorized access to this list could cause the device to ignore packets it should receive and process. /interfaces/interface/enabled: This leaf controls if an interface is enabled or not. Unauthorized access to this leaf could cause the device to ignore packets it should receive and process. Bjorklund Expires August 10, 2013 [Page 24] Internet-Draft YANG Interface Management February 2013 8. Acknowledgments The author wishes to thank Alexander Clemm, Per Hedeland, Ladislav Lhotka, and Juergen Schoenwaelder for their helpful comments. Bjorklund Expires August 10, 2013 [Page 25] Internet-Draft YANG Interface Management February 2013 9. References 9.1. Normative References [I-D.ietf-netmod-iana-if-type] Bjorklund, M., "IANA Interface Type and Address Family YANG Modules", draft-ietf-netmod-iana-if-type-02 (work in progress), April 2012. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2863] McCloghrie, K. and F. Kastenholz, "The Interfaces Group MIB", RFC 2863, June 2000. [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, January 2004. [RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, October 2010. 9.2. Informative References [RFC2579] McCloghrie, K., Ed., Perkins, D., Ed., and J. Schoenwaelder, Ed., "Textual Conventions for SMIv2", STD 58, RFC 2579, April 1999. [RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J., and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, June 2011. [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, June 2011. Bjorklund Expires August 10, 2013 [Page 26] Internet-Draft YANG Interface Management February 2013 Appendix A. Example: Ethernet Interface Module This section gives a simple example of how an Ethernet interface module could be defined. It demonstrates how media-specific configuration parameters can be conditionally augmented to the generic interface list. It is not intended as a complete module for ethernet configuration. Bjorklund Expires August 10, 2013 [Page 27] Internet-Draft YANG Interface Management February 2013 module ex-ethernet { namespace "http://example.com/ethernet"; prefix "eth"; import ietf-interfaces { prefix if; } augment "/if:interfaces/if:interface" { when "if:type = 'ethernetCsmacd'"; container ethernet { must "../if:location" { description "An ethernet interface must specify the physical location of the ethernet hardware."; } choice transmission-params { case auto { leaf auto-negotiate { type empty; } } case manual { leaf duplex { type enumeration { enum "half"; enum "full"; } } leaf speed { type enumeration { enum "10Mb"; enum "100Mb"; enum "1Gb"; enum "10Gb"; } } } } // other ethernet specific params... } } } Bjorklund Expires August 10, 2013 [Page 28] Internet-Draft YANG Interface Management February 2013 Appendix B. Example: Ethernet Bonding Interface Module This section gives an example of how interface layering can be defined. An ethernet bonding interface is defined, which bonds several ethernet interfaces into one logical interface. module ex-ethernet-bonding { namespace "http://example.com/ethernet-bonding"; prefix "bond"; import ietf-interfaces { prefix if; } augment "/if:interfaces/if:interface" { when "if:type = 'ieee8023adLag'"; leaf-list slave-if { type if:interface-ref; must "/if:interfaces/if:interface[if:name = current()]" + "/if:type = 'ethernetCsmacd'" { description "The type of a slave interface must be ethernet."; } } leaf bonding-mode { type enumeration { enum round-robin; enum active-backup; enum broadcast; } } // other bonding config params, failover times etc. } } Bjorklund Expires August 10, 2013 [Page 29] Internet-Draft YANG Interface Management February 2013 Appendix C. Example: VLAN Interface Module This section gives an example of how a vlan interface module can be defined. module ex-vlan { namespace "http://example.com/vlan"; prefix "vlan"; import ietf-interfaces { prefix if; } augment "/if:interfaces/if:interface" { when "if:type = 'ethernetCsmacd' or if:type = 'ieee8023adLag'"; leaf vlan-tagging { type boolean; default false; } } augment "/if:interfaces/if:interface" { when "if:type = 'l2vlan'"; leaf base-interface { type if:interface-ref; must "/if:interfaces/if:interface[if:name = current()]" + "/vlan:vlan-tagging = true" { description "The base interface must have vlan tagging enabled."; } } leaf vlan-id { type uint16 { range "1..4094"; } must "../base-interface" { description "If a vlan-id is defined, a base-interface must be specified."; } } } } Bjorklund Expires August 10, 2013 [Page 30] Internet-Draft YANG Interface Management February 2013 Appendix D. Example: NETCONF reply This section gives an example of a reply to the NETCONF request for a device that implements the example data models above. eth0 ethernetCsmacd 0 true 2 eth1 ethernetCsmacd 1 true 7 true Bjorklund Expires August 10, 2013 [Page 31] Internet-Draft YANG Interface Management February 2013 Appendix E. Examples: Interface Naming Schemes This section gives examples of some implementation strategies. E.1. Router with Restricted Interface Names In this example, a router has support for 4 line cards, each with 8 ports. The slots for the cards are physically numbered from 0 to 3, and the ports on each card from 0 to 7. Each card has fast- or gigabit-ethernet ports. The implementation restricts the names of the interfaces to one of "fastethernet-N/M" or "gigabitethernet-N/M". The "location" of an interface is a string on the form "N/M". The implementation auto- initializes the values for "type" and "location" based on the interface name. An operator can configure a new interface by sending an containing: fastethernet-1/0 When the server processes this request, it will set the leaf "type" to "ethernetCsmacd" and "location" to "1/0". Thus, if the client performs a right after the above, it will get: fastethernet-1/0 ethernetCsmacd 1/0 If the client tries to change the location of this interface with an containing: fastethernet-1/0 1/1 then the server will reply with an "invalid-value" error, since the new location does not match the name. Bjorklund Expires August 10, 2013 [Page 32] Internet-Draft YANG Interface Management February 2013 E.2. Router with Arbitrary Interface Names In this example, a router has support for 4 line cards, each with 8 ports. The slots for the cards are physically numbered from 0 to 3, and the ports on each card from 0 to 7. Each card has fast- or gigabit-ethernet ports. The implementation does not restrict the interface names. This allows to more easily apply the interface configuration to a different physical interface. However, the additional level of indirection also makes it a bit more complex to map interface names found in other protocols to configuration entries. The "location" of an interface is a string on the form "N/M". An operator can configure a new interface by sending an containing: acme-interface ethernetCsmacd 1/0 If necessary, the operator can move the configuration named "acme-interface" over to a different physical interface with an containing: acme-interface 2/4 E.3. Ethernet Switch with Restricted Interface Names In this example, an ethernet switch has a number of ports, each port identified by a simple port number. The implementation restricts the interface names to numbers that match the physical port number. An operator can configure a new interface by sending an containing: 6 When the server processes this request, it will set the leaf "type" Bjorklund Expires August 10, 2013 [Page 33] Internet-Draft YANG Interface Management February 2013 to "ethernetCsmacd" and "location" to "6". Thus, if the client performs a right after the above, it will get: 6 ethernetCsmacd 6 If the client tries to change the location of this interface with an containing: 6 5 then the server will reply with an "invalid-value" error, since the new location does not match the name. E.4. Generic Host with Restricted Interface Names In this example, a generic host has interfaces named by the kernel and without easily usable location information. The system identifies the physical interface by the name assigned by the operating system to the interface. The implementation restricts the interface name to the operating system level name of the physical interface. An operator can configure a new interface by sending an containing: eth8 When the server processes this request, it will set the leaf "type" to "ethernetCsmacd" and "location" to "eth8". Thus, if the client performs a right after the above, it will get: eth8 ethernetCsmacd eth8 Bjorklund Expires August 10, 2013 [Page 34] Internet-Draft YANG Interface Management February 2013 If the client tries to change the location of this interface with an containing: eth8 eth7 then the server will reply with an "invalid-value" error, since the new location does not match the name. E.5. Generic Host with Arbitrary Interface Names In this example, a generic host has interfaces named by the kernel and without easily usable location information. The system identifies the physical interface by the name assigned by the operating system to the interface. The implementation does not restrict the interface name to the operating system level name of the physical interface. This allows to more easily apply the interface configuration to a different physical interface. However, the additional level of indirection also makes it a bit more complex to map interface names found in other protocols to configuration entries. An operator can configure a new interface by sending an containing: acme-interface ethernetCsmacd eth4 If necessary, the operator can move the configuration named "acme-interface" over to a different physical interface with an containing: acme-interface eth3 Bjorklund Expires August 10, 2013 [Page 35] Internet-Draft YANG Interface Management February 2013 Appendix F. ChangeLog RFC Editor: remove this section upon publication as an RFC. F.1. Version -08 o Removed the mtu leaf. o Added examples of different interface naming schemes. F.2. Version -07 o Made leaf speed config false. F.3. Version -06 o Added oper-status leaf. o Added leaf-lists higher-layer-if and lower-layer-if, that show the interface layering. o Added container statistics with counters. F.4. Version -05 o Added an Informative References section. o Updated the Security Considerations section. o Clarified the behavior of an NETCONF server when invalid values are received. F.5. Version -04 o Clarified why ifPromiscuousMode is not part of this data model. o Added a table that shows the mapping between this YANG data model and IF-MIB. F.6. Version -03 o Added the section Relationship to the IF-MIB. o Changed if-index to be a leaf instead of leaf-list. o Explained the notation used in the data model tree picture. Bjorklund Expires August 10, 2013 [Page 36] Internet-Draft YANG Interface Management February 2013 F.7. Version -02 o Editorial fixes F.8. Version -01 o Changed leaf "if-admin-status" to leaf "enabled". o Added Security Considerations Bjorklund Expires August 10, 2013 [Page 37] Internet-Draft YANG Interface Management February 2013 Author's Address Martin Bjorklund Tail-f Systems Email: mbj@tail-f.com Bjorklund Expires August 10, 2013 [Page 38]