NVO3 WG T. Ao Internet-Draft ZTE Corporation Intended status: Standards Track G. Mirsky Expires: August 31, 2018 ZTE Corp. Y. Fan China Telecom February 27, 2018 Multi-encapsulation interconnection for Overlay Virtual Network draft-ao-nvo3-multi-encap-interconnect-00 Abstract For an virtualized overlay network, there are many encapsulations that may be used. Different customer have their own preference. So if some of these different encapsulation can be interconnected together, the virtualized overlay network would be more compatible and have loose strict on access. This document is going to provide an architecture of different overlay encapsulation interconnection and an tranformer gateway for these end station connected to the virtual network. 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 August 31, 2018. 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 Ao, et al. Expires August 31, 2018 [Page 1] Internet-Draft multiple encapsulation interconnect February 2018 publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions used in this document . . . . . . . . . . . . . . 3 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 3. Multi-encapsulation NVO architecture . . . . . . . . . . . . 3 3.1. Transformer NVE . . . . . . . . . . . . . . . . . . . . . 5 4. Control Plane . . . . . . . . . . . . . . . . . . . . . . . . 6 4.1. NVE to NVA . . . . . . . . . . . . . . . . . . . . . . . 6 4.2. NVA to NVE . . . . . . . . . . . . . . . . . . . . . . . 7 4.3. NVA to NVA . . . . . . . . . . . . . . . . . . . . . . . 7 5. Security Considerations . . . . . . . . . . . . . . . . . . . 7 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 7.1. Normative References . . . . . . . . . . . . . . . . . . 7 7.2. Informational References . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 1. Introduction Network virtualization using Overlays over Layer 3 (NVO3) is a technology that is used to address issues that arise in building large, multi-tenant data centers that make extensive use of server virtualization. With the progress in NVO3 WG, some of the data plane encapsulations have been put forward, some are outstanding dataplane for overlay network, such as VxLAN-GPE [I-D.ietf-nvo3-vxlan-gpe], GENEVE [I-D.ietf-nvo3-geneve] and GUE [I-D.ietf-nvo3-encap], etc. The consideration about these overlay encapsulations has been analysised in [I-D.ietf-nvo3-encap]. The fact is that each of them have its custmers, and furthermore, some of them have been provisioned in the network. So that a problem arises: for a virtual network, all the hosts that connect to the same VN and want to communicate with each other are required to have the same data plane encapsulation. This problem limite the network scalability and capacity. Especially, when the NVE is located on the vSwitch, the encapsulation method on the NVE is not predictable. Allowing as many kinds of accession as possible is more attractive for a virtualized overlay network. Ao, et al. Expires August 31, 2018 [Page 2] Internet-Draft multiple encapsulation interconnect February 2018 To improve the scalability and capacity of the virtualized overlay network, we propose a multi-encapsulation access allowed interconnect NVO3 architecture, and a gateway in the network to perform the transformation for different encapsulation in this document, by which these hosts with different encapsulations can be interconnected. Here we call the gateway as Transformer Gateway in the following descrption. 2. Conventions used in this document 2.1. Terminology NVO3: Network Virtualization using Overlay over Layer 3 NVA: Network Virtualization Authority TS: Tenant System VxLAN-GPE: Virtual extension LAN with Generic Protocol Extension GENEVE: Generic Network Virtualization Encapsulation GUE: Generic UDP Encapsulation Multi-encapsulation NVO: an virtualized overlay network that allow multiple different encapsulations interconnection. t-GW: Tranformation Gateway. A gateway that do the transformer for different encapsulation to make them can communicate with each other. tNVE: A NVE that complete the functionn of a tranformer gateway. 2.2. 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. 3. Multi-encapsulation NVO architecture In the multi-encapsulation interconnection allowed NVO, different NVE may support different encapsulation data plane. As we have know that any two of the TS in the same VN should communicate with each other, but it is required that both of overaly encapsulation they are using to access to the virtual network have to be same. In order to relieve the limitation and to support these encapsulation would Ao, et al. Expires August 31, 2018 [Page 3] Internet-Draft multiple encapsulation interconnect February 2018 interconnect together, a multi-encapsulation architecture is introdueced. Figure 1 dipcts a reference architecture in VN. +--------+ | Tenant +--+ | System4| | +--------+ | .................. | +---+ +---------------+ +--|NVE|---+ +---|Transformer NVE| +---+ | | | (tNVE) | /. | | +---------------+ / . +-----+ . / . +--| NVA |--+ . / . | +-----+ \ . | . | \ . | . | Overlay +--+--++--------+ +--------+ | . | Network | NVE || Tenant | | Tenant +--+ . | | || System5| | System3| . \ +---+ +--+--++--------+ +--------+ .....|NVE|......... +---+ | | ===================== | | +--------+ +--------+ | Tenant | | Tenant | | System1| | System2| +--------+ +--------+ Figure 1 Multi-encapsulation VN architecture Figure 1: Multi-encapsulation interconnection architecture In this figure, a Transformer Gateway component is introduced. Generally, the gateway is located on a NVE, so we call it as tNVE. For the TSs in the same virtual network, if the NVE they connecting have different encapsulation, want to communicate with each other, Transformer NVE(tNVE) will take over as a gateway to provide a "bridge" for the communication. That is, when different NVEs want to set up tunnel, if they can't connect each other directly because of different encapsulation, they can set up a tunnel with tNVE seperately, so that the tNVE connects the two tunnels as a transfer. There could be more than one tNVE in a network. Ao, et al. Expires August 31, 2018 [Page 4] Internet-Draft multiple encapsulation interconnect February 2018 3.1. Transformer NVE Transformer NVE(tNVE) is a certain kind of NVE that maybe appointed by NVA or by manager. As a very important component in the multi- encapsulation NVO, one requirement for NVE being a Transfomer NVE is that the NVE should support at least two kinds of encapsulations. With reference to the [RFC8014], the Transformer NVE has a reference model as showed in Figure 2. | | | Data-Center Network (IP) | +-----------------------------------------------------------+ | | | | | Tunnel Overlay | | Tunnel Overlay | +---------+----+ +--+----------+----+ +-----+--------+ | +----------+ | | +--------------+ | | +----------+ | | | Overlay | | | | Overlay | | | | Overlay | | | | Module | | | | Module | | | | Module | | | +----+-----+ | | +---+----------+ | | +----------+ | | | | | | | | | | | | NVE1 | | | tNVE| | | | NVE3 | | | +---+----+ | | +---+-+ +--+--+ | | +--------+ | | | VNI1 | | | |VNI1 | |VNI1 | | | | VNI1 | | | +-+------+ | | +-+---+ +-----+ | | +-+------+ | | | VAP1 | | |VAP1 |VAP2| | | VAP1 | +----+---------+ | +---------+ | +----+---------+ | +------------------+ | |\ | -----+-\------------------------------------------------------+------- TSI1 |TSI2\ Tenant TSI1 | +---+ +---+ +---+ |TS1| |TS2| |TS3| +---+ +---+ +---+ Figure 2 tNVE Reference Model Figure 2: tNVE reference model tNVE is a key component for the connection between NVE1 and NVE2. It can be a dedicated device and be a NVE that also provide the overlay network for the TSs. When the NVE takes the role of transform different encapsulation for different TSs, it will not forward the traffic to TS, but to another VAP that support the encapsulation the destination NVE owned. Take the Figure 2 as an example to illustrate how does tNVE work. NVE1 only support VxLAN-GPE, and NVE2 only support GENEVE. For the two communiting TSs: TS1 wants to send packets to TS3, and TS3 also Ao, et al. Expires August 31, 2018 [Page 5] Internet-Draft multiple encapsulation interconnect February 2018 wants to reply to TS1. They are in the same VNID1, but the NVE they are connecting using different encapsulation. So if the two TS communicate with each other, packets have to transfer at tNVE. For NVE1, it has no sense that TS3 is connecting to NVE3, instead assuming that TS3 is connecting to tNVE. In the same way, for NVE3, it has no sense that TS1 is connecting to NVE1, instead of assuming that TS1 is connecting to tNVE. So because of the existence of the tNVE, no matter TS1/TS3 or NVE1/NVE3, they never perceive that they are in different data plane. NVE1 getting the packets from TS1 encapsulates them in Vxlan-GPE and then send the packets to tNVE. The tNVE gets the packets from the Vxlan-GPE tunnel and then de- encapsulate the vxLAN-GPE to VAP1. Next the tNVE forward packets to the Overlay Module from VAP2 to have another encapsulation GENEVE on the packets. At last tNVE forward the packet in the GENEVE tunnel to NVE3. From the above, tNVE is like a tranformer between TS1 and TS2. And owning to tNVE, even though NVE1 and NVE2 which TS1 and TS2 connecting seperately have different encapsulation, as long as they are in the same virtual network, they would communicate each other and no need to have knowledge that they are in different data plane. 4. Control Plane As stated in [RFC8014], an NVA is the entity that provides address mapping and other information to NVEs. In addition, information flows between NVEs and NVAs in both directions. The NVA maintains information about all VNs in the NV Domain so that NVEs do not need to do so themselves. NVEs obtain information from the NVA about where a given remote TS destination resides. NVAs, in turn, obtain information from NVEs about the individual TSs attached to those NVEs. Therefore, in order to make the tNVE works properly and to make sure that all the other network entities except tNVE don't detect the difference, NVA should detect the role of tNVE and take the coordination role among tNVE and other NVEs, maintain the information about the tNVEs and other NVEs, compute the tunnel connection, and notify tNVEs and NVEs about remote TS information. 4.1. NVE to NVA NVE and tNVE should not only notify the NVA the address mapping between NVE and TSs, but also notify the NVA which encapsulation tunnel does this mapping use, so that NVA be able to decide which connection need tNVE participation. Information from tNVE to NVA: Ao, et al. Expires August 31, 2018 [Page 6] Internet-Draft multiple encapsulation interconnect February 2018 1. Encapsulations the tNVE support. Information from NVE to NVA: 1. The address mapping between NVE and its attached TSs. 2. The encapsulation tunnel the address mapping will use. 3. The mandate metadata the address mapping must use. 4.2. NVA to NVE NVA notify the NVE and tNVE the mapping information after computing and coordination. Information from NVA to NVE: 1. The address mapping information between remote NVE and TS. The NVE here may not be the NVE that the TS is connecting. It may be a tNVE. Information from NVA to tNVE: 1. The address mapping information between remote NVE and its connecting TS. 4.3. NVA to NVA For NVA federate scenario. To be added in the future updates. 5. Security Considerations Will be added in the future updates. 6. IANA Considerations TBD. 7. References 7.1. Normative References [I-D.ietf-intarea-gue] Herbert, T., Yong, L., and O. Zia, "Generic UDP Encapsulation", draft-ietf-intarea-gue-05 (work in progress), December 2017. Ao, et al. Expires August 31, 2018 [Page 7] Internet-Draft multiple encapsulation interconnect February 2018 [I-D.ietf-nvo3-geneve] Gross, J., Ganga, I., and T. Sridhar, "Geneve: Generic Network Virtualization Encapsulation", draft-ietf- nvo3-geneve-05 (work in progress), September 2017. [I-D.ietf-nvo3-vxlan-gpe] Maino, F., Kreeger, L., and U. Elzur, "Generic Protocol Extension for VXLAN", draft-ietf-nvo3-vxlan-gpe-05 (work in progress), October 2017. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC7365] Lasserre, M., Balus, F., Morin, T., Bitar, N., and Y. Rekhter, "Framework for Data Center (DC) Network Virtualization", RFC 7365, DOI 10.17487/RFC7365, October 2014, . [RFC8014] Black, D., Hudson, J., Kreeger, L., Lasserre, M., and T. Narten, "An Architecture for Data-Center Network Virtualization over Layer 3 (NVO3)", RFC 8014, DOI 10.17487/RFC8014, December 2016, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 7.2. Informational References [I-D.ietf-nvo3-encap] Boutros, S., Ganga, I., Garg, P., Manur, R., Mizrahi, T., Mozes, D., Nordmark, E., Smith, M., Aldrin, S., and I. Bagdonas, "NVO3 Encapsulation Considerations", draft-ietf- nvo3-encap-01 (work in progress), October 2017. [RFC7364] Narten, T., Ed., Gray, E., Ed., Black, D., Fang, L., Kreeger, L., and M. Napierala, "Problem Statement: Overlays for Network Virtualization", RFC 7364, DOI 10.17487/RFC7364, October 2014, . Ao, et al. Expires August 31, 2018 [Page 8] Internet-Draft multiple encapsulation interconnect February 2018 Authors' Addresses Ting Ao ZTE Corporation No.889, BiBo Road Shanghai 201203 China Phone: +86 21 68897642 Email: ao.ting@zte.com.cn Greg Mirsky ZTE Corp. 1900 McCarthy Blvd. #205 Milpitas, CA 95035 USA Email: gregimirsky@gmail.com Yongbin China Telecom No.109, Zhongshan Avenue Guangzhou 510630 China Email: fanyb@gsta.com Ao, et al. Expires August 31, 2018 [Page 9]