NVGRE: Network Virtualization Using Generic Routing Encapsulation
RFC 7637
| Document | Type |
RFC - Informational
(September 2015; No errata)
Was draft-sridharan-virtualization-nvgre (individual)
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|---|---|---|---|
| Authors | Pankaj Garg , Yu-Shun Wang | ||
| Last updated | 2015-10-14 | ||
| Stream | ISE | ||
| Formats | plain text html pdf htmlized bibtex | ||
| IETF conflict review | conflict-review-sridharan-virtualization-nvgre | ||
| Stream | ISE state | Published RFC | |
| Consensus Boilerplate | Unknown | ||
| Document shepherd | Adrian Farrel | ||
| Shepherd write-up | Show (last changed 2015-04-21) | ||
| IESG | IESG state | RFC 7637 (Informational) | |
| Telechat date | |||
| Responsible AD | (None) | ||
| Send notices to | (None) | ||
| IANA | IANA review state | IANA OK - No Actions Needed | |
| IANA action state | No IANA Actions | ||
Independent Submission P. Garg, Ed. Request for Comments: 7637 Y. Wang, Ed. Category: Informational Microsoft ISSN: 2070-1721 September 2015 NVGRE: Network Virtualization Using Generic Routing Encapsulation Abstract This document describes the usage of the Generic Routing Encapsulation (GRE) header for Network Virtualization (NVGRE) in multi-tenant data centers. Network Virtualization decouples virtual networks and addresses from physical network infrastructure, providing isolation and concurrency between multiple virtual networks on the same physical network infrastructure. This document also introduces a Network Virtualization framework to illustrate the use cases, but the focus is on specifying the data-plane aspect of NVGRE. Status of This Memo This document is not an Internet Standards Track specification; it is published for informational purposes. This is a contribution to the RFC Series, independently of any other RFC stream. The RFC Editor has chosen to publish this document at its discretion and makes no statement about its value for implementation or deployment. Documents approved for publication by the RFC Editor are not a candidate for any level of Internet Standard; see Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7637. Copyright Notice Copyright (c) 2015 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. Garg & Wang Informational [Page 1] RFC 7637 NVGRE September 2015 Table of Contents 1. Introduction ....................................................2 1.1. Terminology ................................................4 2. Conventions Used in This Document ...............................4 3. Network Virtualization Using GRE (NVGRE) ........................4 3.1. NVGRE Endpoint .............................................5 3.2. NVGRE Frame Format .........................................5 3.3. Inner Tag as Defined by IEEE 802.1Q ........................8 3.4. Reserved VSID ..............................................8 4. NVGRE Deployment Considerations .................................9 4.1. ECMP Support ...............................................9 4.2. Broadcast and Multicast Traffic ............................9 4.3. Unicast Traffic ............................................9 4.4. IP Fragmentation ..........................................10 4.5. Address/Policy Management and Routing .....................10 4.6. Cross-Subnet, Cross-Premise Communication .................10 4.7. Internet Connectivity .....................................12 4.8. Management and Control Planes .............................12 4.9. NVGRE-Aware Devices .......................................12 4.10. Network Scalability with NVGRE ...........................13 5. Security Considerations ........................................14 6. Normative References ...........................................14 Contributors ......................................................16 Authors' Addresses ................................................17 1. Introduction Conventional data center network designs cater to largely static workloads and cause fragmentation of network and server capacity [6] [7]. There are several issues that limit dynamic allocation and consolidation of capacity. Layer 2 networks use the Rapid Spanning Tree Protocol (RSTP), which is designed to eliminate loops by blocking redundant paths. These eliminated paths translate to wasted capacity and a highly oversubscribed network. There are alternative approaches such as the Transparent Interconnection of Lots of Links (TRILL) that address this problem [13]. The network utilization inefficiencies are exacerbated by network fragmentation due to the use of VLANs for broadcast isolation. VLANs are used for traffic management and also as the mechanism for providing security and performance isolation among services belonging to different tenants. The Layer 2 network is carved into smaller- sized subnets (typically, one subnet per VLAN), with VLAN tags configured on all the Layer 2 switches connected to server racks thatShow full document text