[Docs] [txt|pdf|xml|html] [Tracker] [Email] [Nits]

Versions: 00 draft-xiao-nvo3-bfd-geneve

BFD Working Group                                                 X. Min
Internet-Draft                                                 G. Mirsky
Intended status: Standards Track                                     ZTE
Expires: May 27, 2019                                  November 23, 2018


                             BFD for Geneve
                        draft-xiao-bfd-geneve-00

Abstract

   This document describes the use of the Bidirectional Forwarding
   Detection (BFD) protocol in Generic Network Virtualization
   Encapsulation (Geneve) overlay networks.

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 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 May 27, 2019.

Copyright Notice

   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.





Min & Mirsky              Expires May 27, 2019                  [Page 1]


Internet-Draft               BFD for Geneve                November 2018


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Conventions Used in This Document . . . . . . . . . . . .   2
       1.1.1.  Terminology . . . . . . . . . . . . . . . . . . . . .   2
       1.1.2.  Requirements Language . . . . . . . . . . . . . . . .   3
   2.  BFD Packet Transmission over Geneve Tunnel  . . . . . . . . .   3
     2.1.  BFD Packet Encapsulation in Geneve  . . . . . . . . . . .   3
       2.1.1.  BFD Encapsulation With IP/UDP Header  . . . . . . . .   3
       2.1.2.  BFD Encapsulation Without IP/UDP Header . . . . . . .   5
   3.  Reception of BFD packet from Geneve Tunnel  . . . . . . . . .   7
     3.1.  Demultiplexing of the BFD packet  . . . . . . . . . . . .   8
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   9
   7.  Normative References  . . . . . . . . . . . . . . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Introduction

   "Generic Network Virtualization Encapsulation" (Geneve)
   [I-D.ietf-nvo3-geneve] provides a generic tunneling protocol that is
   applicable to many scenarios, including an encapsulation scheme that
   allows virtual machines (VMs) to communicate in a data center
   network.

   This document describes the use of Bidirectional Forwarding Detection
   (BFD) protocol for Geneve to enable monitoring continuity of the path
   between Network Virtualization Edges (NVEs) and/or availability of a
   replicator service node using BFD.

   The use cases and the deployment of BFD for Geneve are consistent
   with what's described in Section 3 and Section 4 of
   [I-D.ietf-bfd-vxlan].  The main difference between Geneve and
   "Virtual eXtensible Local Area Network" (VXLAN) [RFC7348]
   encapsulation is that Geneve supports multi-protocol payload and
   variable length options.

1.1.  Conventions Used in This Document

1.1.1.  Terminology

   BFD: Bidirectional Forwarding Detection

   Geneve: Generic Network Virtualization Encapsulation

   NVE: Network Virtualization Edge




Min & Mirsky              Expires May 27, 2019                  [Page 2]


Internet-Draft               BFD for Geneve                November 2018


   VFI: Virtual Forwarding Instance

   VM: Virtual Machine

   VNI: Virtual Network Identifier

   VXLAN: Virtual eXtensible Local Area Network

1.1.2.  Requirements Language

   The key words "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] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

2.  BFD Packet Transmission over Geneve Tunnel

   BFD packet MUST be encapsulated and sent to a remote NVE using one of
   the options described in Section 2.1.  Implementations SHOULD ensure
   that the BFD packets follow the same lookup path as Geneve data
   packets within the sender system.

2.1.  BFD Packet Encapsulation in Geneve

   Concerning whether or not the Geneve data packets include an IP
   protocol data unit, this document defines three options of BFD packet
   encapsulation in Geneve.

2.1.1.  BFD Encapsulation With IP/UDP Header

   If the Protocol Type field (as defined in Section 3.4 of
   [I-D.ietf-nvo3-geneve]) of data packets indicates that there exists
   an inner IP header, i.e., the Protocol Type equals to 0x6558
   (Ethernet frame), or 0x0800 (IPv4), or 0x86DD (IPv6), or 0x8847
   (MPLS), or 0x8848 (MPLS with the upstream-assigned label), then BFD
   packets are encapsulated in Geneve as described below.  The Geneve
   packet format over IPv4 is defined in Section 3.1 of
   [I-D.ietf-nvo3-geneve].  The Geneve packet format over IPv6 is
   defined in Section 3.2 of [I-D.ietf-nvo3-geneve].  The Outer IP/UDP
   and Geneve headers MUST be encoded by the sender as defined in
   [I-D.ietf-nvo3-geneve].  Note that the outer IP header and the inner
   IP header may not be of the same address family, in other words,
   outer IPv6 header accompanied with inner IPv4 header and outer IPv4
   header accompanied with inner IPv6 header are both possible.






Min & Mirsky              Expires May 27, 2019                  [Page 3]


Internet-Draft               BFD for Geneve                November 2018


    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                      Outer Ethernet Header                    ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                        Outer IPvX Header                      ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                        Outer UDP Header                       ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                          Geneve Header                        ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                        Inner IPvX Header                      ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                         Inner UDP Header                      ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                       BFD Control Message                     ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                               FCS                             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Figure 1: Geneve Encapsulation of BFD Control Message With the Inner
                               IP/UDP Header

   When the BFD packets are encapsulated in Geneve in this way, the BFD
   packet MUST be carried inside the inner IP packet of the Geneve
   packet.  The inner IP packet carrying the BFD payload has the
   following format:

      IP header:

         Source IP: IP address of the originating NVE.

         Destination IP: IP address of the terminating NVE.



Min & Mirsky              Expires May 27, 2019                  [Page 4]


Internet-Draft               BFD for Geneve                November 2018


         TTL: MUST be set to 1 to ensure that the BFD packet is not
         routed within the L3 underlay network.

      The fields of the UDP header and the BFD control packet are
      encoded as specified in [RFC5881].

   When the BFD packets are encapsulated in Geneve in this way, the
   Geneve header SHOULD follow the value set below.


    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Ver|  Opt Len  |O|C|    Rsvd.  |          Protocol Type        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |        Virtual Network Identifier (VNI)       |    Reserved   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Variable Length Options                    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                          Figure 2: Geneve Header

   Opt Len field SHOULD be set to 0, which indicates there isn't any
   variable length option.

   [Ed.Note]: Use of O bit is still being discussed in the NVO3 WG, so
   the value is undetermined.

   C bit SHOULD be set to 0.

   Protocol Type field SHOULD be set to 0x0800 (IPv4) or 0x86DD (IPv6).

2.1.2.  BFD Encapsulation Without IP/UDP Header

   Alternatively to the use of the inner IP/UDP header to demultiplex
   BFD control packet by the value of the destination UDP port, BFD
   control packet MAY be encapsulated without the inner IP/UDP header.
   The BFD control packet MAY be identified directly in the Geneve
   header or through Geneve OAM shim.  In either case, the Outer IP/UDP
   and Geneve headers MUST be encoded by the sender as defined in
   [I-D.ietf-nvo3-geneve].

   Figure 3 displays the layout of the Ethernet frame with BFD control
   packet encapsulated in Geneve without the use of IP/UDP header and
   identified by the value TBA1 (to be assigned by IANA) of the Protocol
   Type field.




Min & Mirsky              Expires May 27, 2019                  [Page 5]


Internet-Draft               BFD for Geneve                November 2018


    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                      Outer Ethernet Header                    ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                        Outer IPvX Header                      ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                        Outer UDP Header                       ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                          Geneve Header                        ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                       BFD Control Message                     ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                               FCS                             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


     Figure 3: Geneve Encapsulation of BFD Control Message Without the
                            Inner IP/UDP Header

   When the BFD packets are encapsulated in Geneve in this way, the BFD
   packet MUST immediately follow the Geneve header, and the Geneve
   header SHOULD follow the value set below.

   Opt Len field SHOULD be set to 0, which indicates there isn't any
   variable length option.

   [Ed.Note]: Use of O bit is still being discussed in the NVO3 WG, so
   the value is undetermined.

   C bit SHOULD be set to 0.

   Also, if BFD control packet is encapsulated in Geneve without the use
   of IP/UDP header, the BFD control packet MAY be identified through
   the Geneve OAM shim.  The layout of the Ethernet frame is shown in
   Figure 4.  Protocol Type field MUST be set to the value TBA2 (to be
   assigned by IANA) which indicates a Geneve OAM shim that will have a
   field to indicate the inner BFD control packet.  Definition of the



Min & Mirsky              Expires May 27, 2019                  [Page 6]


Internet-Draft               BFD for Geneve                November 2018


   format of the Geneve OAM shim is outside the scope of this document.
   The Geneve OAM shim immediately follows the Geneve header, and the
   BFD control packet immediately follows the Geneve OAM shim.


    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                      Outer Ethernet Header                    ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                        Outer IPvX Header                      ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                        Outer UDP Header                       ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                          Geneve Header                        ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        Geneve OAM Shim                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                       BFD Control Message                     ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                               FCS                             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Figure 4: Geneve Encapsulation of BFD Control Message With Geneve OAM
                                   Shim

3.  Reception of BFD packet from Geneve Tunnel

   Once a packet is received, NVE MUST validate the packet as described
   in [I-D.ietf-nvo3-geneve].

   If the Protocol Type field equals 0x0800 (IPv4) or 0x86DD (IPv6), and
   the Destination IP of the inner IP packet matches the IP address of
   the NVE, the UDP destination port and the TTL of the inner IP packet
   MUST be validated to determine whether BFD can process the received
   packet.  BFD packet with inner IP set to NVE MUST NOT be forwarded to
   VMs.



Min & Mirsky              Expires May 27, 2019                  [Page 7]


Internet-Draft               BFD for Geneve                November 2018


   If the Protocol Type field equals the value TBA1 (to be assigned by
   IANA) which indicates an inner BFD control message, the received
   packet MUST be processed by BFD and MUST NOT be forwarded to VMs.

   If the Protocol Type field equals the value TBA2 (to be assigned by
   IANA) which indicates a Geneve OAM shim that will have a field to
   indicate the inner BFD control message, the received packet MUST be
   processed by BFD and MUST NOT be forwarded to VMs.  This case is for
   further study.

   To ensure BFD detects the proper configuration of Virtual Network
   Identifier (VNI) in a remote NVE, a lookup SHOULD be performed with
   the MAC-DA/IP-DA/MPLS-Label and VNI as key in the Virtual Forwarding
   Instance (VFI) table of the originating/terminating NVE to exercise
   the VFI associated with the VNI.

3.1.  Demultiplexing of the BFD packet

   If the Protocol Type field equals 0x0800 (IPv4) or 0x86DD (IPv6),
   demultiplexing of IP BFD packet has been defined in Section 3 of
   [RFC5881].  Since multiple BFD sessions may be running between two
   NVEs, there needs to be a mechanism for demultiplexing received BFD
   packets to the proper session.  The procedure for demultiplexing
   packets with Your Discriminator equal to 0 is different from
   [RFC5880].  For such packets, the BFD session MUST be identified
   using the inner headers, i.e., the source IP and the destination IP
   present in the IP header carried by the payload of the Geneve
   encapsulated packet.  The VNI of the packet SHOULD be used to derive
   interface-related information for demultiplexing the packet.  If BFD
   packet is received with non-zero Your Discriminator, then BFD session
   MUST be demultiplexed only with Your Discriminator as the key.

   If the Protocol Type field equals the value TBA1 (to be assigned by
   IANA) which indicates an inner BFD control message, or the value TBA2
   (to be assigned by IANA) which indicates a Geneve OAM shim that will
   have a field to indicate the inner BFD control message, the VNI of
   the packet SHOULD be used to derive interface-related information for
   demultiplexing the packet, demultiplexing of BFD packet MUST rely on
   non-zero Your Discriminator as the key.

4.  Security Considerations

   This document does not raise any additional security issues beyond
   those of the specifications referred to in the list of normative
   references.






Min & Mirsky              Expires May 27, 2019                  [Page 8]


Internet-Draft               BFD for Geneve                November 2018


5.  IANA Considerations

   In the Geneve Protocol Type registry defined in [ETYPES], a new BFD
   Control Message or Geneve OAM Shim is requested from IANA as follows:

   +----------------+-----------------+------------------+-------------+
   | Geneve         | Description     | Semantics        | Reference   |
   | Protocol Type  |                 | Definition       |             |
   +----------------+-----------------+------------------+-------------+
   | TBA1           | BFD Control     | Section 3.1      | This        |
   |                | Message         |                  | Document    |
   | TBA2           | Geneve OAM Shim | Section 3.1      | This        |
   |                |                 |                  | Document    |
   +----------------+-----------------+------------------+-------------+

       Table 1: New BFD Control Message or Geneve OAM shim Ethertype

6.  Acknowledgements

   To be added.

7.  Normative References

   [ETYPES]   The IEEE Registration Authority, "IEEE 802 Numbers", 2013,
              <http://www.iana.org/assignments/ieee-802-numbers/
              ieee-802-numbers.xml>.

   [I-D.ietf-bfd-vxlan]
              Networks, J., Paragiri, S., Govindan, V., Mudigonda, M.,
              and G. Mirsky, "BFD for VXLAN", draft-ietf-bfd-vxlan-03
              (work in progress), October 2018.

   [I-D.ietf-nvo3-geneve]
              Gross, J., Ganga, I., and T. Sridhar, "Geneve: Generic
              Network Virtualization Encapsulation", draft-ietf-
              nvo3-geneve-08 (work in progress), October 2018.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC5880]  Katz, D. and D. Ward, "Bidirectional Forwarding Detection
              (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010,
              <https://www.rfc-editor.org/info/rfc5880>.






Min & Mirsky              Expires May 27, 2019                  [Page 9]


Internet-Draft               BFD for Geneve                November 2018


   [RFC5881]  Katz, D. and D. Ward, "Bidirectional Forwarding Detection
              (BFD) for IPv4 and IPv6 (Single Hop)", RFC 5881,
              DOI 10.17487/RFC5881, June 2010,
              <https://www.rfc-editor.org/info/rfc5881>.

   [RFC7348]  Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
              L., Sridhar, T., Bursell, M., and C. Wright, "Virtual
              eXtensible Local Area Network (VXLAN): A Framework for
              Overlaying Virtualized Layer 2 Networks over Layer 3
              Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014,
              <https://www.rfc-editor.org/info/rfc7348>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

Authors' Addresses

   Xiao Min
   ZTE
   Nanjing
   China

   Phone: +86 25 88016574
   Email: xiao.min2@zte.com.cn


   Greg Mirsky
   ZTE
   USA

   Email: gregimirsky@gmail.com



















Min & Mirsky              Expires May 27, 2019                 [Page 10]


Html markup produced by rfcmarkup 1.129d, available from https://tools.ietf.org/tools/rfcmarkup/