Movatterモバイル変換

Internet Engineering Task Force (IETF)                         J. ArangoRequest for Comments: 8059                                     S. VenaasCategory: Experimental                                     Cisco SystemsISSN: 2070-1721                                              I. Kouvelas                                                    Arista Networks Inc.                                                            D. Farinacci                                                             lispers.net                                                            January 2017PIM Join Attributesfor Locator/ID Separation Protocol (LISP) EnvironmentsAbstract   This document defines two PIM Join/Prune attributes that support the   construction of multicast distribution trees where the root and   receivers are located in different Locator/ID Separation Protocol   (LISP) sites.  These attributes allow the receiver site to select   between unicast and multicast underlying transport and to convey the   RLOC (Routing Locator) address of the receiver ETR (Egress Tunnel   Router) to the control plane of the root ITR (Ingress Tunnel Router).Status of This Memo   This document is not an Internet Standards Track specification; it is   published for examination, experimental implementation, and   evaluation.   This document defines an Experimental Protocol for the Internet   community.  This document is a product of the Internet Engineering   Task Force (IETF).  It represents the consensus of the IETF   community.  It has received public review and has been approved for   publication by the Internet Engineering Steering Group (IESG).  Not   all documents approved by the IESG are a candidate for any level of   Internet Standard; seeSection 2 of RFC 7841.   Information about the current status of this document, any errata,   and how to provide feedback on it may be obtained athttp://www.rfc-editor.org/info/rfc8059.Arango, et al.                Experimental                      [Page 1]

RFC 8059        PIM Join Attributes for LISP Environments   January 2017Copyright Notice   Copyright (c) 2017 IETF Trust and the persons identified as the   document authors.  All rights reserved.   This document is subject toBCP 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.Table of Contents1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .22.  Requirements Notation . . . . . . . . . . . . . . . . . . . .33.  PIM Join/Prune Attributes . . . . . . . . . . . . . . . . . .34.  The Transport Attribute . . . . . . . . . . . . . . . . . . .44.1.  Transport Attribute Format  . . . . . . . . . . . . . . .44.2.  Using the Transport Attribute . . . . . . . . . . . . . .55.  Receiver ETR RLOC Attribute . . . . . . . . . . . . . . . . .55.1.  Receiver RLOC Attribute Format  . . . . . . . . . . . . .65.2.  Using the Receiver RLOC Attribute . . . . . . . . . . . .66.  Security Considerations . . . . . . . . . . . . . . . . . . .77.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .78.  References  . . . . . . . . . . . . . . . . . . . . . . . . .88.1.  Normative References  . . . . . . . . . . . . . . . . . .88.2.  Informative References  . . . . . . . . . . . . . . . . .8   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .91.  Introduction   The construction of multicast distribution trees where the root and   receivers are located in different LISP sites [RFC6830] is defined in   [RFC6831].  Creation of (root-EID,G) state in the root site requires   that unicast LISP-encapsulated Join/Prune messages be sent from an   ETR on the receiver site to an ITR on the root site.  The term "EID"   is short for "Endpoint ID".   [RFC6831] specifies that (root-EID,G) data packets are to be LISP-   encapsulated into (root-RLOC,G) multicast packets.  However, a wide   deployment of multicast connectivity between LISP sites is unlikely   to happen any time soon.  In fact, some implementations are initially   focusing on unicast transport with head-end replication between root   and receiver sites.Arango, et al.                Experimental                      [Page 2]

RFC 8059        PIM Join Attributes for LISP Environments   January 2017   The unicast LISP-encapsulated Join/Prune message specifies the   (root-EID,G) state that needs to be established in the root site, but   conveys nothing about the receiver's capability or desire to use   multicast as the underlying transport.  This document specifies a   Join/Prune attribute that allows the receiver ETR to select the   desired transport.   The term "transport" in this document is intentionally somewhat   vague.  Currently, it is used just to indicate whether multicast or   head-end replication is used; this means that the outer destination   address is either a unicast or multicast address.  Future documents   may specify how other types of delivery, encapsulation, or underlay   are used.   Knowledge of the receiver ETR's RLOC address is essential to the   control plane of the root ITR.  The RLOC address determines the   downstream destination for unicast head-end replication and   identifies the receiver ETR that needs to be notified should the root   ITR of the distribution tree move to another site.  The root ITR can   change when the source EID is roaming to another LISP site.   Service providers may implement unicast reverse path forwarding   (uRPF) policies requiring that the outer source address of the LISP-   encapsulated Join/Prune message be the address of the receiver ETR's   core-facing interface used to physically transmit the message.   However, due to policy and load-balancing considerations, the outer   source address may not be the RLOC on which the receiver site wishes   to receive a particular flow.  This document specifies a Join/Prune   attribute that conveys the appropriate receiver ETR's RLOC address to   the control plane of the root ITR.   This document uses terminology defined in [RFC6830], such as EID,   RLOC, ITR, and ETR.2.  Requirements Notation   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].3.  PIM Join/Prune Attributes   PIM Join/Prune attributes are defined in [RFC5384] by introducing a   new Encoded-Source type that, in addition to the Join/Prune source,   can carry multiple Type-Length-Value (TLV) attributes.  These   attributes apply to the individual Join/Prune sources on which they   are stored.Arango, et al.                Experimental                      [Page 3]

RFC 8059        PIM Join Attributes for LISP Environments   January 2017   The attributes defined in this document conform to the format of the   encoding type defined in [RFC5384].  The attributes would typically   be the same for all the sources in the Join/Prune message.  Hence, we   RECOMMEND using the hierarchical Join/Prune attribute scheme defined   in [RFC7887].  This hierarchical system allows attributes to be   conveyed in the Upstream Neighbor Address field, thus enabling the   efficient application of a single attribute instance to all the   sources in the Join/Prune message.   LISP Tunnel Routers (xTRs) do not exchange PIM Hello Messages, and   hence no Hello option is defined to negotiate support for these   attributes.  Systems that support unicast head-end replication are   assumed to support these attributes.4.  The Transport Attribute   It is essential that a mechanism be provided by which the desired   transport can be conveyed by receiver sites.  Root sites with   multicast connectivity will want to leverage multicast replication.   However, not all receiver sites can be expected to have multicast   connectivity.  It is thus desirable that root sites be prepared to   support (root-EID,G) state with a mixture of multicast and unicast   output state.  This document specifies a Join/Prune attribute that   allows the receiver to select the desired underlying transport.4.1.  Transport Attribute Format       0                   1                   2       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+      |F|E|  Type = 5 | Length = 1    |  Transport    |      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   F bit:   The Transitive bit.  Specifies whether the attribute is      transitive or non-transitive.  MUST be set to zero.  This      attribute is ALWAYS non-transitive.   E bit:   End-of-Attributes bit.  Specifies whether this attribute is      the last.  Set to zero if there are more attributes.  Set to 1 if      this is the last attribute.   Type:   The Transport Attribute type is 5.   Length:   The length of the Transport Attribute value.  MUST be set      to 1.Arango, et al.                Experimental                      [Page 4]

RFC 8059        PIM Join Attributes for LISP Environments   January 2017   Transport:   The type of transport being requested.  Set to zero for      multicast.  Set to 1 for unicast.  The values from 2 to 255 may be      assigned in the future.4.2.  Using the Transport Attribute   Hierarchical Join/Prune attribute instances [RFC7887] SHOULD be used   when the same Transport Attribute is to be applied to all the sources   within the Join/Prune message or all the sources within a group set.   The root ITR MUST accept Transport Attributes in the Upstream   Neighbor Encoded-Unicast address, Encoded-Group addresses, and   Encoded-Source addresses.   There MUST NOT be more than one Transport Attribute within the same   encoded address.  If an encoded address has more than one instance of   the attribute, the root ITR MUST discard all affected Join/Prune   sources.  The root ITR MUST also discard all affected Join/Prune   sources if the Transport Attribute value is unknown.5.  Receiver ETR RLOC Attribute   When a receiver ETR requests unicast head-end replication for a given   (root-EID,G) entry, the PIM control plane of the root ITR must   maintain an outgoing interface list ("oif-list") entry for the   receiver ETR and its corresponding RLOC address.  This allows the   root ITR to perform unicast LISP-encapsulation of multicast data   packets to each and every receiver ETR that has requested unicast   head-end replication.   The PIM control plane of the root ITR could potentially determine the   RLOC address of the receiver ETR from the outer source address field   of the LISP-encapsulated Join/Prune message.  However, receiver ETRs   are subject to uRPF checks by the network providers on each core-   facing interface.  The outer source address must therefore be the   RLOC of the core-facing interface used to physically transmit the   LISP-encapsulated Join/Prune message.  Due to policy and load-   balancing considerations, that may not be the RLOC on which the   receiver site wishes to receive a particular flow.  This document   specifies a Join/Prune attribute that conveys the appropriate   receiver RLOC address to the PIM control plane of the root ITR.   To support root-EID mobility, receiver ETRs must also be tracked by   the LISP control plane of the root ITR, regardless of the underlying   transport.  When the root-EID moves to a new root ITR in a different   LISP site, the receiver ETRs do not know the root-EID has moved and   therefore do not know the RLOC of the new root ITR.  This is true for   both unicast and multicast transport modes.  The new root ITR does   not have any receiver ETR state.  Therefore, it is the responsibilityArango, et al.                Experimental                      [Page 5]

RFC 8059        PIM Join Attributes for LISP Environments   January 2017   of the old root ITR to inform the receiver ETRs that the root-EID has   moved.  When the old root ITR detects that the root-EID has moved, it   sends a LISP Solicit-Map-Request (SMR) message to each receiver ETR.   The receiver ETRs do a mapping database lookup to retrieve the RLOC   of the new root ITR.  The old root ITR detects that the root-EID has   moved when it receives a Map-Notify from the Map-Server.  The   transmission of the Map-Notify is triggered when the new root ITR   registers the root-EID [EID-MOBILITY].  When a receiver ETR   determines that the root ITR has changed, it will send a LISP-   encapsulated PIM prune message to the old root xTR and a LISP-   encapsulated PIM join message to the new root xTR.5.1.  Receiver RLOC Attribute Format       0                   1                   2                   3       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+      |F|E|  Type = 6 |    Length     |  Addr Family  |  Receiver RLOC      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...   F bit:   The Transitive bit.  Specifies whether this attribute is      transitive or non-transitive.  MUST be set to zero.  This      attribute is ALWAYS non-transitive.   E bit:   End-of-Attributes bit.  Specifies whether this attribute is      the last.  Set to zero if there are more attributes.  Set to 1 if      this is the last attribute.   Type:   The Receiver RLOC Attribute type is 6.   Length:   The length in octets of the attribute value.  MUST be set      to the length in octets of the receiver RLOC address plus 1 octet      to account for the Address Family field.   Addr Family:   The PIM Address Family of the receiver RLOC as defined      in [RFC7761].   Receiver RLOC:   The RLOC address on which the receiver ETR wishes to      receiver the unicast-encapsulated flow.5.2.  Using the Receiver RLOC Attribute   Hierarchical Join/Prune attribute instances [RFC7887] SHOULD be used   when the same Receiver RLOC Attribute is to be applied to all the   sources within the message or all the sources within a group set.   The root ITR MUST accept Transport Attributes in the Upstream   Neighbor Encoded-Unicast address, Encoded-Group addresses, and   Encoded-Source addresses.Arango, et al.                Experimental                      [Page 6]

RFC 8059        PIM Join Attributes for LISP Environments   January 2017   There MUST NOT be more than one Receiver RLOC Attribute within the   same encoded address.  If an encoded address has more than one   instance of the attribute, the root ITR MUST discard all affected   Join/Prune sources.  The root ITR MUST also discard all affected   Join/Prune sources if the address family is unknown or the address   length is incorrect for the specified address family.6.  Security Considerations   Security of Join/Prune attributes is only guaranteed by the security   of the PIM packet.  The attributes specified herein do not enhance or   diminish the privacy or authenticity of a Join/Prune message.  A site   that legitimately or maliciously sends and delivers a Join/Prune   message to another site will equally be able to append these and any   other attributes it wishes.  See [RFC5384] for general security   considerations for Join/Prune attributes.7.  IANA Considerations   Two new PIM Join/Prune attribute types have been assigned: value 5   for the Transport Attribute and value 6 for the Receiver RLOC   Attribute.   The "PIM Join/Prune Transport Types" registry has been created for   the Join/Prune Transport attribute.  The registration policy is IETF   Review [RFC5226], and the values are in the range 0-255.  This   document assigns value 0 for multicast and value 1 for unicast.Arango, et al.                Experimental                      [Page 7]

RFC 8059        PIM Join Attributes for LISP Environments   January 20178.  References8.1.  Normative References   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate              Requirement Levels",BCP 14,RFC 2119,              DOI 10.17487/RFC2119, March 1997,              <http://www.rfc-editor.org/info/rfc2119>.   [RFC5384]  Boers, A., Wijnands, I., and E. Rosen, "The Protocol              Independent Multicast (PIM) Join Attribute Format",RFC 5384, DOI 10.17487/RFC5384, November 2008,              <http://www.rfc-editor.org/info/rfc5384>.   [RFC6830]  Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The              Locator/ID Separation Protocol (LISP)",RFC 6830,              DOI 10.17487/RFC6830, January 2013,              <http://www.rfc-editor.org/info/rfc6830>.   [RFC6831]  Farinacci, D., Meyer, D., Zwiebel, J., and S. Venaas, "The              Locator/ID Separation Protocol (LISP) for Multicast              Environments",RFC 6831, DOI 10.17487/RFC6831, January              2013, <http://www.rfc-editor.org/info/rfc6831>.   [RFC7761]  Fenner, B., Handley, M., Holbrook, H., Kouvelas, I.,              Parekh, R., Zhang, Z., and L. Zheng, "Protocol Independent              Multicast - Sparse Mode (PIM-SM): Protocol Specification              (Revised)", STD 83,RFC 7761, DOI 10.17487/RFC7761, March              2016, <http://www.rfc-editor.org/info/rfc7761>.   [RFC7887]  Venaas, S., Arango, J., and I. Kouvelas, "Hierarchical              Join/Prune Attributes",RFC 7887, DOI 10.17487/RFC7887,              June 2016, <http://www.rfc-editor.org/info/rfc7887>.8.2.  Informative References   [EID-MOBILITY]              Portoles-Comeras, M., Ashtaputre, V., Moreno, V., Maino,              F., and D. Farinacci, "LISP L2/L3 EID Mobility Using a              Unified Control Plane", Work in Progress,draft-portoles-lisp-eid-mobility-01, October 2016.   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an              IANA Considerations Section in RFCs",BCP 26,RFC 5226,              DOI 10.17487/RFC5226, May 2008,              <http://www.rfc-editor.org/info/rfc5226>.Arango, et al.                Experimental                      [Page 8]

RFC 8059        PIM Join Attributes for LISP Environments   January 2017Authors' Addresses   Jesus Arango   Cisco Systems   170 Tasman Drive   San Jose, CA  95134   United States of America   Email: jearango@cisco.com   Stig Venaas   Cisco Systems   170 Tasman Drive   San Jose, CA  95134   United States of America   Email: stig@cisco.com   Isidor Kouvelas   Arista Networks Inc.   5453 Great America Parkway   Santa Clara, CA  95054   United States of America   Email: kouvelas@arista.com   Dino Farinacci   lispers.net   San Jose, CA   United States of America   Email: farinacci@gmail.comArango, et al.                Experimental                      [Page 9]