idnits 2.17.1 draft-snr-bess-evpn-na-flags-06.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The abstract seems to contain references ([RFC4861], [RFC7432]), which it shouldn't. Please replace those with straight textual mentions of the documents in question. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (January 10, 2017) is 2634 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: 'RFC2119' is mentioned on line 173, but not defined Summary: 1 error (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 BESS Workgroup J. Rabadan, Ed. 3 Internet Draft S. Sathappan 4 K. Nagaraj 5 Intended status: Standards Track Nokia 7 Expires: July 14, 2017 January 10, 2017 9 Propagation of IPv6 Neighbor Advertisement Flags in EVPN 10 draft-snr-bess-evpn-na-flags-06 12 Abstract 14 The MAC/IP Advertisement route specified in [RFC7432] can optionally 15 carry IPv4 and IPv6 addresses associated with a MAC address. Remote 16 PEs can use this information to reply locally (act as proxy) to IPv4 17 ARP requests and IPv6 Neighbor Solicitation messages and 18 reduce/suppress the flooding produced by the Address Resolution 19 procedure. However, if the Neighbor information is learnt via EVPN, 20 the PE would not know if a particular IPv6->MAC pair belongs to a 21 host, a router or a host with an anycast address as this information 22 is not carried in the MAC/IP route advertisements. This document 23 proposes an OPTIONAL advertisement of the Flags defined in [RFC4861] 24 along with the EVPN MAC/IP Advertisement routes, so that an EVPN PE 25 implementing a proxy-ND function can reply to Neighbor Solicitations 26 with the correct Flag information in Neighbor Advertisements. 28 Status of this Memo 30 This Internet-Draft is submitted in full conformance with the 31 provisions of BCP 78 and BCP 79. 33 Internet-Drafts are working documents of the Internet Engineering 34 Task Force (IETF), its areas, and its working groups. Note that 35 other groups may also distribute working documents as Internet- 36 Drafts. 38 Internet-Drafts are draft documents valid for a maximum of six months 39 and may be updated, replaced, or obsoleted by other documents 40 at any time. It is inappropriate to use Internet-Drafts as reference 41 material or to cite them other than as "work in progress." 43 The list of current Internet-Drafts can be accessed at 44 http://www.ietf.org/ietf/1id-abstracts.txt 46 The list of Internet-Draft Shadow Directories can be accessed at 47 http://www.ietf.org/shadow.html 49 This Internet-Draft will expire on July 14, 2017. 51 Copyright Notice 53 Copyright (c) 2017 IETF Trust and the persons identified as the 54 document authors. All rights reserved. 56 This document is subject to BCP 78 and the IETF Trust's Legal 57 Provisions Relating to IETF Documents 58 (http://trustee.ietf.org/license-info) in effect on the date of 59 publication of this document. Please review these documents 60 carefully, as they describe your rights and restrictions with respect 61 to this document. Code Components extracted from this document must 62 include Simplified BSD License text as described in Section 4.e of 63 the Trust Legal Provisions and are provided without warranty as 64 described in the Simplified BSD License. 66 Table of Contents 68 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 69 2. The EVPN Neighbor Discovery (ND) Extended Community . . . . . . 3 70 3. Use of the EVPN ND Extended Community . . . . . . . . . . . . . 4 71 4. Conventions used in this document . . . . . . . . . . . . . . . 4 72 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 73 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 74 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 75 7.1. Normative References . . . . . . . . . . . . . . . . . . . 5 76 7.2. Informative References . . . . . . . . . . . . . . . . . . 5 77 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 5 78 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5 80 1. Introduction 82 The MAC/IP Advertisement route specified in [RFC7432] can optionally 83 carry IPv4 and IPv6 addresses associated with a MAC address. Remote 84 PEs can use this information to reply locally (act as proxy) to IPv4 85 ARP requests and IPv6 Neighbor Solicitation messages and 86 reduce/suppress the flooding produced by the Address Resolution 87 procedure. However, if the Neighbor information is learned via EVPN, 88 the PE would not know if a particular IPv6->MAC pair belongs to a 89 host or a router as this information is not carried in the MAC/IP 90 route advertisements. 92 This document proposes the OPTIONAL advertisement of the Flags 93 defined in [RFC4861] along with the EVPN MAC/IP Advertisement routes, 94 so that an EVPN PE implementing a proxy-ND function can issue 95 Neighbor Advertisement messages conveying the correct Flag 96 information. 98 The Flags are carried in the Neighbor Discovery (ND) EVPN Extended 99 Community, as described in the following sections. 101 2. The EVPN Neighbor Discovery (ND) Extended Community 103 This document defines a new EVPN Extended Community with a Type field 104 value of 0x06 and a Sub-Type TBD. It MAY be advertised along with 105 EVPN MAC/IP Advertisement routes that carry an IPv6 address. 107 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 1 108 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 109 | Type=0x06 | Sub-Type= TBD |Reserved=0 |O|R| Reserved=0 | 110 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 111 | Reserved=0 | 112 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 114 The following Flags are defined in the third octet of the Extended 115 Community: 117 R - Router flag. 119 The low-order bit of the third octet is defined as the "Router flag". 120 When set, the R-bit indicates that the IPv6->MAC pair advertised 121 along with the MAC/IP Advertisement route belongs to a router. If the 122 R-bit is zero, the IPv6-MAC pair belongs to a "host". The receiving 123 PE implementing the proxy-ND function will use this information in 124 Neighbor Advertisement messages for the associated IPv6 address. 126 O - Override flag 128 The second bit of the third octet is defined as the "Override flag". 129 An egress PE will normally advertise IPv6->MAC pairs with the O-bit 130 set, and only when IPv6 "anycast" is enabled in the EVI, the PE will 131 send an IPv6->MAC pair with the O-bit = 0. The ingress PE will 132 install the proxy-ND entry with the received O-bit and will use this 133 information when replying to a Neighbor Solicitation for the IPv6 134 address. 136 3. Use of the EVPN ND Extended Community 138 An EVPN PE supporting a proxy-ND function and implementing the 139 propagation of the Neighbor Advertisement Flags will follow this 140 procedure: 142 a) Transmission of the EVPN ND Extended Community 144 A PE may learn the IPv6->MAC pair and its associated ND Flags in 145 the management plane or snooping Neighbor Advertisement messages 146 coming from the CE. Either way, the PE SHOULD send a MAC/IP 147 Advertisement route including the learned IPv6->MAC pair and MAY 148 send the ND Extended Community carrying its associated "R" and "O" 149 Flags. This new Extended Community does not have any impact on the 150 rest of the procedures described in [RFC7432], including the 151 advertisement of the MAC Mobility Extended Community along with 152 the MAC/IP Advertisement route. 154 b) Reception of the EVPN ND Extended Community 156 In addition to the procedures specified in [RFC7432] a PE 157 receiving a MAC/IP Advertisement route containing an IPv6 address 158 and the ND Extended Community SHOULD add the R and O Flags to the 159 proxy-ND entry for the IPv6->MAC entry and use that information in 160 Neighbor Advertisements when replying to a Solicitation for the 161 IPv6 address. 163 A PE that implements the proxy-ND function SHOULD have an 164 administrative option to define the default Flag to be used in case 165 no EVPN ND Extended Community is received for a given IPv6->MAC 166 entry. 168 4. Conventions used in this document 170 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 171 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 172 document are to be interpreted as described in RFC-2119 [RFC2119]. 174 In this document, these words will appear with that interpretation 175 only when in ALL CAPS. Lower case uses of these words are not to be 176 interpreted as carrying RFC-2119 significance. 178 In this document, the characters ">>" preceding an indented line(s) 179 indicates a compliance requirement statement using the key words 180 listed above. This convention aids reviewers in quickly identifying 181 or finding the explicit compliance requirements of this RFC. 183 5. Security Considerations 185 The same security considerations described in [RFC7432] apply to this 186 document. 188 6. IANA Considerations 190 This document requests the registration of a new EVPN Extended 191 Community sub-type: 193 Sub-Type Name Reference 195 0x08 ND Extended Community [this document] 197 7. References 199 7.1. Normative References 201 [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, 202 "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, DOI 203 10.17487/RFC4861, September 2007, . 206 [RFC7432] Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A., 207 Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based Ethernet 208 VPN", RFC 7432, DOI 10.17487/RFC7432, February 2015, . 211 7.2. Informative References 213 8. Acknowledgments 215 Authors' Addresses 216 Jorge Rabadan (Editor) 217 Nokia 218 777 E. Middlefield Road 219 Mountain View, CA 94043 USA 220 Email: jorge.rabadan@nokia.com 222 Senthil Sathappan 223 Nokia 224 701 E. Middlefield Road 225 Mountain View, CA 94043 USA 226 Email: senthil.sathappan@nokia.com 228 Kiran Nagaraj 229 701 E. Middlefield Road 230 Nokia 231 Email: kiran.nagaraj@nokia.com