I2RS working group S. Hares Internet-Draft Huawei Intended status: Standards Track R. White Expires: October 6, 2016 LinkedIn April 4, 2016 Filter-Based RIB Data Model draft-hares-rtgwg-fb-rib-01 Abstract This document defines a yang data model for a Filter-based Routing Information Base (RIB) Yang data model. A routing system uses the Filter-based RIB to program FIB entries that process incoming packets by matching on multiple fields (n-tuple) within the packet and then performing a specified action on it. The FB-RIB can also specify an action to forward the packet according to the FIB entries programmed using the RIBs of its routing instance. 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 October 6, 2016. Copyright Notice Copyright (c) 2016 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 Hares & White Expires October 6, 2016 [Page 1] Internet-Draft Filter-Base RIB DM April 2016 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 1.1. Definition of I2RS Filter Based RIB . . . . . . . . . . . 2 1.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 1.3. Definitions and Acronyms . . . . . . . . . . . . . . . . 3 1.4. Yang High Level (YHL) graphical form . . . . . . . . . . 4 2. Where Filter-Based RIB Fits in Global RIBs . . . . . . . . . 5 3. Proposed Structure for Filter-Based RIBs . . . . . . . . . . 7 4. Yang High Level Structure for FB-RIBs . . . . . . . . . . . . 8 4.1. Top Level Yang Structure for ietf-fb-rib . . . . . . . . 9 4.2. Filter-Based RIB structures . . . . . . . . . . . . . . . 10 5. yang models . . . . . . . . . . . . . . . . . . . . . . . . . 11 5.1. Filter-Based RIB types . . . . . . . . . . . . . . . . . 11 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 7. Security Considerations . . . . . . . . . . . . . . . . . . . 11 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 8.1. Normative References: . . . . . . . . . . . . . . . . . . 12 8.2. Informative References . . . . . . . . . . . . . . . . . 12 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 1. Introduction This document provides a yang module for flow filter n-tuple policy that is locally configured. This flow filter policy has also been called Policy routing in some implementations. This document defines a yang data model for a Filter-based Routing Information Base (RIB) Yang data model. A routing system uses the Filter-based RIB to program FIB entries that process incoming packets by matching on multiple fields within the packet and then performing a specified action on it. The FB-RIB can also specify an action to forward the packet according to the FIB entries programmed using the RIBs of its routing instance. 1.1. Definition of I2RS Filter Based RIB Filter-based routing is a technique used to make packet forwarding decisions based on a n-tuple filter that is matched to the incoming packets and the specified action. It should be noted that that this is distinct from the static routes in the following RIBS: o configured RIB created using static routes in [I-D.ietf-netmod-routing-cfg] Hares & White Expires October 6, 2016 [Page 2] Internet-Draft Filter-Base RIB DM April 2016 o Extended static RIB defined in [I-D.acee-rtgwg-yang-rib-extend], o Ephmeral Protocol Independent RIB defined in [I-D.ietf-i2rs-rib-info-model], or A Filter-Based RIB (Routing Information Base) is contained in a routing instance. It contains a list of filters (match-action conditions), a list of interface the filter-based forwarding operates on. Filter-based RIBs (FB-RIBs) operate only on the interface the FB-RIB are configured on. A Filter Based RIB uses packet forwarding policy. If packet reception is considered an event, then the I2RS Filter-based RIB uses a minimalistic Event-Condition-Action policy. A Filter-based RIB entry specifies matche filters for the fields in a packet (which may include layer 1 to layer 3 header fields, transport or application fields) or size of the packet or interface received on. The matches are contained in an ordered list of filters which contain pairs of match condition-action (aka event-condition-action). If all matches fail, the default action is to forward the packet using FIB entries that were programmed by the default Routing Informational Base (RIB) manager configured in the Filter-Based RIB (FB-RB) Actions in the condition-action pair may impact forwarding or set something in the packet that will impact forwarding. Policy actions are typically applied before applying QoS constraints since policy actions may override QoS constraint. The Filter-Based RIB resides in ephemeral state as does the I2RS RIB and I2RS topology models. 1.2. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [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. 1.3. Definitions and Acronyms CLI Command Line Interface Hares & White Expires October 6, 2016 [Page 3] Internet-Draft Filter-Base RIB DM April 2016 FB-RIB Filter-Based Routing Information Base FB-Route The policy rules in the filter-based RIB are prescriptive of the Event-Condition-Action form which is often represented by if Condition then action. All policy in the filter-based RIB are in a ordered list, ordered by "order-number". Order number is similar to some CLI concepts of line number. Policy Group Policy Groups are groups of policy rules that are set-up for the convenience of operators who wish to link the rules connected to a particular client. * Groups do not affect the order of policy rulies. * The policy groups in the basic network policy [I-D.hares-i2rs-pkt-eca-data-model] allow grouping of policy by name. This name allow easier management of customer-based or provider based filters. This policy group is a second way to access certain policy rules on the policy rule list. RIB IM RIB Informational Model (RIB IM) [I-D.ietf-i2rs-rib-info-model] Routing instance A routing instance, in the context of the FB-FIB is a collection of RIBs, interfaces, and routing parameters. A routing instance creates a logical slice of the router and allows different logical slices; across a set of routers; to communicate with each other. 1.4. Yang High Level (YHL) graphical form The High-level Yang graphical representation uses the following symbols: Brackets "[" and "]" enclose list keys. Curly braces "{" and "}" contain names of optional features that make the corresponding node conditional. Hares & White Expires October 6, 2016 [Page 4] Internet-Draft Filter-Base RIB DM April 2016 Abbreviations before data node names: "rw" means configuration (read-write), "ro" state data (read-only), "-x" RPC operations, and "-n" notifications. Symbols after data node names: "?" means an optional node, "!" a container with presence, and "*" denotes a "list" or "leaf-list". Parentheses enclose choice and case nodes, and case nodes are also marked with a colon (":"). Ellipsis ("...") stands for contents of subtrees that are not shown. 2. Where Filter-Based RIB Fits in Global RIBs The Top-level Yang structure for a global FB-RIB types (similar to acl) is not defined. The Filter-Based RIB should be defined under this structure under a routing instance. The two things under this RIB would be: configured Filter-Based RIB (aka Policy routing), I2RS reboot Ephemeral Filter-Based RIB. ACLs [I-D.ietf-netmod-acl-model] have the potential to be augmented to be included, but this version of this document does address that issue. The purpose of this section is illustrate why the flow specification policy installed in yang modules loaded into intended configuration needs to be able to be compared. After demonstrating why this is needed, this section suggests a structure for filter-based RIBS. BGP's Flow Specification (BGP-FS) configures filter-based policy in the local BGP configuration, and passes this information in BGP packets (in NLRI and Extended Communities). The BGP-FS YANG model [I-D.wu-idr-flowspec-yang-cfg] specifies the locally configuration, and the derived state that includes the BGP Flow Specifications received. BGP-FS processing may install the locally configured BGP Flow specification in the local FB-RIB. If it does, this policy is like any other locally configured policy. The BGP-FS may installed the flow policy received from a remote BGP peer and stored in derived state. This policy has a different characteristics as it will disappear if the peer connection between the two peers drops, or if the peer changes the BGP-FS policy. Due to the ephemeral nature of the BGP-FS, it should be installed unique. Otherwise, If the local configuration state changes, it cannot differentiate between the true configured state and the ephemeral states (I2RS ephemeral and BGP-session ephemeral). Both I2RS ephemeral and BGP-session ephemeral policy will disappear upon a reboot. Hares & White Expires October 6, 2016 [Page 5] Internet-Draft Filter-Base RIB DM April 2016 ietf-fb-rib module +--rw routing-instance +--rw ietf-fb-rib +--rw default-instance-name string +--rw default-router-id rt:router-id +--rw config-fb-rib // config state uses fb-ribs +--rw I2rs-fb-rib // ephemeral state uses fb-ribs +--rw BGP-FB-RIB // Install derived uses fb-ribs // BGP-FS policy state Figure 6: Global FB RIB Yang Structure I2RS architecture [I-D.ietf-i2rs-architecture] specifies that by default the Local configuration will win if the local configuration changes. In the NETCONF/NETMOD language, the "last write wins". An example will help illustrate this: local configuration installs filter for IP-Dest=128.2/16, IP- SRC=192.5.7/24 DPORT=ALL drop in the running configuration, and then synchronously loads it to the intended configuration and applied configuration. I2RS installs an ephemeral filter for IP-Dest=128.2/16, IP- SRC=192.5.7/24 DPORT=125 forward intended configuration synchronously. BGP-FS processing installs BGP-FS policy for IP-Dest=128.2/16, IP- SRC=192.5.7/24 DPORT=125 forward, traffic-rate by bytes. local configuration install a filter for IP-Dest=128.2/16, IP- SRC=192.5.7/24, DPort=125, drop. This local configuration policy would win over the I2RS policy and the BGP-FS. The I2RS process is required to receive an event indicating the overwrite. The BGP-FS process should also receive an event indicating an overwrite. The I2RS [I-D.ietf-i2rs-architecture] also allows that the preference between local-configuration and I2RS ephemeral state can be determined by operator-applied policy. However, illustrations of this are out of scope for this version of this document. Hares & White Expires October 6, 2016 [Page 6] Internet-Draft Filter-Base RIB DM April 2016 3. Proposed Structure for Filter-Based RIBs There are three levels in the Filter-Based RIBs (FB-RIB) structure: o a global FB-RIB structures, o the common structure of the FB-RIB, and o the groupings that make up the FB-RIB All structures have two types: configuration/ephemeral state and operational state. This yang model describes three types of FB-RIBS: configuration, I2RS, and BGP Flow Specification. The configuration FB-RIB yang module is config state ("config true" and "ephemeral false") and survives a reboot. The I2RS FB-RB yang model is reboot ephemeral ("config true" and "ephemeral true"). The BGP Flow Specification Filter-Based RIB stores policy which is received by the BGP peers, and can be considered policy configured as part of BGP infrastructure ("config true" and "peer-ephemeral true;") Hares & White Expires October 6, 2016 [Page 7] Internet-Draft Filter-Base RIB DM April 2016 Configuration RIBS bgp-fs-fb-rib - is the BGP processes installation of the BGP Flow Specification (BGP-FS) policy rules from remote peers. Locally configured BGP-FS rules are configured in the BGP peer structure. +-----------------------------------------+ | routing instance | +-------|-------------|----------------|--+ | | | | | | +---------|----+ +-----|-----+ +--------|-----+ |config-fb-rib | |i2rs-fb-rib| |bgp-fs-fb-rib | +------|-------+ +-----|------+ +------|------+ |............:....|...............| : (uses common structures : in separate lists of FB-RIBs) +--------|----+ |fb-ribs* | | | +--|----------+ | Figure 3: Routing instance with three types of Filter-FIB lists 4. Yang High Level Structure for FB-RIBs The following section provides the high level yang structure diagrams for the following levels of structures for both config/ephemeral state and operationa. o ietf-fb-rib - contains filter-based RIBS for config, I2RS FB-RIB, and BGP Flow Specification. o fb-rib - that contains the structures for the filter-based grouping o fb-rib-types - that contains the structures for groupings within the filter-based RIBS These structures are contained within the yang section in this draft. The packet-reception ECA policy yang module is contained in the draft [I-D.hares-i2rs-pkt-eca-data-model]. Hares & White Expires October 6, 2016 [Page 8] Internet-Draft Filter-Base RIB DM April 2016 For those who desire more information regarding the logic behind the I2RS Filter-Based RIB, please see the Informational Model at: [I-D.kini-i2rs-fb-rib-info-model]. 4.1. Top Level Yang Structure for ietf-fb-rib The Top-level Yang structure for a global FB-RIB types (similar to acl) is not defined for filter-based RIBS. The I2RS Filter-Based RIB should be defined under this structure under a routing instance. The three things under this RIB would be: configured Filter-Based RIB (aka Policy routing), I2RS reboot Ephemeral Filter-Based RIB, and BGP Flow Specification's Filter-Based RIB. All of these RIBs have similar actions. There are two types top-level structures for ietf-fb-ribs: config and operational state. The Top-level Yang structure for a global configuration of Filter- Based RIBs are: Augments rt:logical-network-elements:\ :logical-network-element:network-instances: \ network-instance ietf-fb-rib module +--rw ietf-fb-rib +--rw default-instance-name string +--rw default-router-id rt:router-id +--rw config-fb-ribs if-feature "config-filter-based-RIB"; uses fb-ribs; +--rw i2rs-fb-ribs if-feature "I2RS-filter-based-RIB"; uses fb-rib-t:fb-ribs; +--rw bgp-fs-fb-ribs if-feature "BGP-FS-filter-based-RIB"; uses fb-rib-t:fb-ribs; Figure 5: configuration state The Top-level Yang structure for a global operational state of Filter-Based RIBs are: Hares & White Expires October 6, 2016 [Page 9] Internet-Draft Filter-Base RIB DM April 2016 Augments rt:logical-network-elements:\ :logical-network-element:network-instances: \ network-instance ietf-fb-rib module +--rw ietf-fb-rib-opstate +--rw default-instance-name string +--rw default-router-id rt:router-id +--rw config-fb-rib-opstate if-feature "config-filter-based-RIB"; uses fb-rib-t:fb-ribs-oper-status; +--rw i2rs-fb-rib-opstate { if-feature "I2RS-filter-based-RIB"; uses fb-rib-t:fb-ribs-oper-status; +--rw bgp-fs-fb-rib-opstate if-feature "BGP-FS-filter-based-RIB"; uses fb-rib-t:fb-ribs-oper-status; Figure 5: operational state 4.2. Filter-Based RIB structures The Top-level yang structures at the Filter-Based RIB level have two types: configuration and operational state. The Top-level Yang structure for the FB-RIB types is: Hares & White Expires October 6, 2016 [Page 10] Internet-Draft Filter-Base RIB DM April 2016 module: fb-rib-types: +--rw fb-ribs +--rw fb-rib* [rib-name] | +--rw rib-name string | | rw fb-type identityref / ephemeral or not | +--rw rib-afi rt:address-family | +--rw fb-rib-intf* [name] | | +--rw name string | | +--rw intf if:interface | +--rw default-rib | | +--rw rt-rib rt:routing:routing-instance:name | | +--rw config-rib string; // config rib name | | +--rw i2rs-rib:routing-instance:name | | +--rw i2rs-rib string; //ephemeral rib name | | +--rw bgp-instance-name string | | +--rw bgp-rib string //session ephemeral | +--rw fb-rib-refs | | +--rw fb-rib-update-ref uint32 /count of writes | +--rw instance-using* | | device:networking-instance:networking-instance-name | +--use pkt-eca:pkt-eca-policy-set Figure 6: FB RIB Type Structure HIgh Level Yang +--rw fb-ribs-oper-status +--rw fb-rib-oper-status* [fb-rib-name] uses pkt-eca:pkt-eca-opstate 5. yang models 5.1. Filter-Based RIB types Yang model is contained in draft-hares-i2rs-fb-rib-data-model-01.txt Please see this draft for the data model. 6. IANA Considerations TBD 7. Security Considerations A I2RS RIB is ephemeral data store that will dyanamically change traffic paths set by the routing configuration. An I2RS FB-RIB provides dynamic Event-Condition-Action policy that will further change the operation of forwarding by allow dyanmic policy and Hares & White Expires October 6, 2016 [Page 11] Internet-Draft Filter-Base RIB DM April 2016 ephemeral RIBs to alter the traffic paths set by routing configuration. Care must be taken in deployments to use the appropriate security and operational control to make use of the tools the I2RS RIB and I2RS FB-RIB provide. 8. References 8.1. Normative References: [I-D.acee-rtgwg-yang-rib-extend] Lindem, A. and Y. Qu, "RIB YANG Data Model", draft-acee- rtgwg-yang-rib-extend-01 (work in progress), March 2016. [I-D.hares-i2rs-fb-rib-data-model] Hares, S., Kini, S., Dunbar, L., Krishnan, R., Bogdanovic, D., and R. White, "Filter-Based RIB Data Model", draft- hares-i2rs-fb-rib-data-model-03 (work in progress), March 2016. [I-D.hares-i2rs-pkt-eca-data-model] Hares, S., Wu, Q., and R. White, "Filter-Based Packet Forwarding ECA Policy", draft-hares-i2rs-pkt-eca-data- model-02 (work in progress), February 2016. [I-D.ietf-i2rs-rib-data-model] Wang, L., Ananthakrishnan, H., Chen, M., amit.dass@ericsson.com, a., Kini, S., and N. Bahadur, "A YANG Data Model for Routing Information Base (RIB)", draft-ietf-i2rs-rib-data-model-05 (work in progress), March 2016. [I-D.ietf-netmod-routing-cfg] Lhotka, L. and A. Lindem, "A YANG Data Model for Routing Management", draft-ietf-netmod-routing-cfg-21 (work in progress), March 2016. [I-D.wu-idr-flowspec-yang-cfg] Wu, N., Zhuang, S., and A. Choudhary, "A YANG Data Model for Flow Specification", draft-wu-idr-flowspec-yang-cfg-02 (work in progress), October 2015. 8.2. Informative References [I-D.ietf-i2rs-architecture] Atlas, A., Halpern, J., Hares, S., Ward, D., and T. Nadeau, "An Architecture for the Interface to the Routing System", draft-ietf-i2rs-architecture-13 (work in progress), February 2016. Hares & White Expires October 6, 2016 [Page 12] Internet-Draft Filter-Base RIB DM April 2016 [I-D.ietf-i2rs-rib-info-model] Bahadur, N., Kini, S., and J. Medved, "Routing Information Base Info Model", draft-ietf-i2rs-rib-info-model-08 (work in progress), October 2015. [I-D.ietf-i2rs-usecase-reqs-summary] Hares, S. and M. Chen, "Summary of I2RS Use Case Requirements", draft-ietf-i2rs-usecase-reqs-summary-02 (work in progress), March 2016. [I-D.ietf-netmod-acl-model] Bogdanovic, D., Koushik, K., Huang, L., and D. Blair, "Network Access Control List (ACL) YANG Data Model", draft-ietf-netmod-acl-model-07 (work in progress), March 2016. [I-D.kini-i2rs-fb-rib-info-model] Kini, S., Hares, S., Dunbar, L., Ghanwani, A., Krishnan, R., Bogdanovic, D., and R. White, "Filter-Based RIB Information Model", draft-kini-i2rs-fb-rib-info-model-03 (work in progress), February 2016. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . Authors' Addresses Susan Hares Huawei 7453 Hickory Hill Saline, MI 48176 USA Email: shares@ndzh.com Russ White LinkedIn Email: russ@riw.us Hares & White Expires October 6, 2016 [Page 13]