idnits 2.17.1 draft-rabadan-l2vpn-evpn-prefix-advertisement-02.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 : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (July 4, 2014) is 3585 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: 'RFC4364' is mentioned on line 309, but not defined == Missing Reference: 'RFC2119' is mentioned on line 1087, but not defined == Outdated reference: A later version (-11) exists of draft-ietf-l2vpn-evpn-03 == Outdated reference: A later version (-05) exists of draft-sajassi-l2vpn-evpn-inter-subnet-forwarding-04 Summary: 0 errors (**), 0 flaws (~~), 5 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 L2VPN Workgroup J. Rabadan 3 Internet Draft W. Henderickx 4 S. Palislamovic 5 Intended status: Standards Track Alcatel-Lucent 7 J. Drake F. Balus 8 Juniper Nuage Networks 10 A. Sajassi A. Isaac 11 Cisco Bloomberg 13 Expires: January 5, 2015 July 4, 2014 15 IP Prefix Advertisement in EVPN 16 draft-rabadan-l2vpn-evpn-prefix-advertisement-02 18 Abstract 20 EVPN provides a flexible control plane that allows intra-subnet 21 connectivity in an IP/MPLS and/or an NVO-based network. In NVO 22 networks, there is also a need for a dynamic and efficient inter- 23 subnet connectivity across Tenant Systems and End Devices that can be 24 physical or virtual and may not support their own routing protocols. 25 This document defines a new EVPN route type for the advertisement of 26 IP Prefixes and explains some use-case examples where this new route- 27 type is used. 29 Status of this Memo 31 This Internet-Draft is submitted in full conformance with the 32 provisions of BCP 78 and BCP 79. 34 Internet-Drafts are working documents of the Internet Engineering 35 Task Force (IETF), its areas, and its working groups. Note that 36 other groups may also distribute working documents as Internet- 37 Drafts. 39 Internet-Drafts are draft documents valid for a maximum of six months 40 and may be updated, replaced, or obsoleted by other documents at any 41 time. It is inappropriate to use Internet-Drafts as reference 42 material or to cite them other than as "work in progress." 44 The list of current Internet-Drafts can be accessed at 45 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 January 5, 2015. 51 Copyright Notice 53 Copyright (c) 2014 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. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 69 2. Introduction and problem statement . . . . . . . . . . . . . . 3 70 2.1 Inter-subnet connectivity requirements in Data Centers . . . 4 71 2.2 The requirement for advertising IP prefixes in EVPN . . . . 6 72 2.3 The requirement for a new EVPN route type . . . . . . . . . 7 73 3. The BGP EVPN IP Prefix route . . . . . . . . . . . . . . . . . 9 74 3.1 IP Prefix Route encoding . . . . . . . . . . . . . . . . . . 9 75 4. Benefits of using the EVPN IP Prefix route . . . . . . . . . . 11 76 5. IP Prefix next-hop use-cases . . . . . . . . . . . . . . . . . 12 77 5.1 TS IP address next-hop use-case . . . . . . . . . . . . . . 12 78 5.2 Floating IP next-hop use-case . . . . . . . . . . . . . . . 15 79 5.3 IRB IP next-hop use-case . . . . . . . . . . . . . . . . . . 16 80 5.4 ESI next-hop ("Bump in the wire") use-case . . . . . . . . . 18 81 5.5 IRB forwarding without core-facing IRB use-case 82 (VRF-to-VRF) . . . . . . . . . . . . . . . . . . . . . . . . 20 83 6. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . 23 84 7. Conventions used in this document . . . . . . . . . . . . . . . 24 85 8. Security Considerations . . . . . . . . . . . . . . . . . . . . 24 86 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 24 87 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 24 88 10.1 Normative References . . . . . . . . . . . . . . . . . . . 24 89 10.2 Informative References . . . . . . . . . . . . . . . . . . 24 90 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 24 91 12. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 24 93 1. Terminology 95 GW IP: Gateway IP Address 97 IPL: IP address length 99 IRB: Integrated Routing and Bridging interface 101 ML: MAC address length 103 NVE: Network Virtualization Edge 105 TS: Tenant System 107 VA: Virtual Appliance 109 RT-2: EVPN route type 2, i.e. MAC/IP advertisement route 111 RT-5: EVPN route type 5, i.e. IP Prefix route 113 Overlay next-hop: object used in the IP Prefix route, as described in 114 this document. It can be an IP address in the tenant space or an ESI, 115 and identifies the next-hop to be used in IP lookups for a given IP 116 Prefix at the routing context importing the route. 118 Underlay next-hop: IP address sent by BGP along with any EVPN route, 119 i.e. BGP next-hop. It identifies the NVE sending the route and it is 120 used at the receiving NVE as the VXLAN destination VTEP or NVGRE 121 destination end-point. 123 2. Introduction and problem statement 125 Inter-subnet connectivity is required for certain tenants within the 126 Data Center. [EVPN-INTERSUBNET] defines some fairly common inter- 127 subnet forwarding scenarios where TSes can exchange packets with TSes 128 located in remote subnets. In order to meet this requirement, [EVPN- 129 INTERSUBNET] describes how MAC/IPs encoded in TS RT-2 routes are not 130 only used to populate MAC-VRF and overlay ARP tables, but also IP-VRF 131 tables with the encoded TS host routes (/32 or /128). In some cases, 132 EVPN may advertise IP Prefixes and therefore provide aggregation in 133 the IP-VRF tables, as opposed to program individual host routes. This 134 document complements the scenarios described in [EVPN-INTERSUBNET] 135 and defines how EVPN may be used to advertise IP Prefixes. 137 Section 2.1 describes the inter-subnet connectivity requirements in 138 Data Centers. Section 2.2 and 2.3 explain why neither IP-VPN nor the 139 existing EVPN route types meet the requirements for IP Prefix 140 advertisements. Once the need for a new EVPN route type is justified, 141 sections 2 and 3 will describe this route type and how it is used in 142 some specific use cases. 144 2.1 Inter-subnet connectivity requirements in Data Centers 146 [EVPN] is used as the control plane for a Network Virtualization 147 Overlay (NVO3) solution in Data Centers (DC), where Network 148 Virtualization Edge (NVE) devices can be located in Hypervisors or 149 TORs, as described in [EVPN-OVERLAYS]. 151 If we use the term Tenant System (TS) to designate a physical or 152 virtual system identified by MAC and IP addresses, and connected to 153 an EVPN instance, the following considerations apply: 155 o The Tenant Systems may be Virtual Machines (VMs) that generate 156 traffic from their own MAC and IP. 158 o The Tenant Systems may be Virtual Appliance entities (VAs) that 159 forward traffic to/from IP addresses of different End Devices 160 seating behind them. 162 o These VAs can be firewalls, load balancers, NAT devices, other 163 appliances or virtual gateways with virtual routing instances. 165 o These VAs do not have their own routing protocols and hence 166 rely on the EVPN NVEs to advertise the routes on their behalf. 168 o In all these cases, the VA will forward traffic to the Data 169 Center using its own source MAC but the source IP will be the 170 one associated to the End Device seating behind or a 171 translated IP address (part of a public NAT pool) if the VA is 172 performing NAT. 174 o Note that the same IP address could exist behind two of these 175 TS. One example of this would be certain appliance resiliency 176 mechanisms, where a virtual IP or floating IP can be owned by 177 one of the two VAs running the resiliency protocol (the master 178 VA). VRRP is one particular example of this. Another example 179 is multi-homed subnets, i.e. the same subnet is connected to 180 two VAs. 182 o Although these VAs provide IP connectivity to VMs and subnets 183 behind them, they do not always have their own IP interface 184 connected to the EVPN NVE, e.g. layer-2 firewalls are examples 185 of VAs not supporting IP interfaces. 187 The following figure illustrates some of the examples described 188 above. 190 NVE1 191 +--------+ 192 TS1(VM)--|(EVI-10)|---------+ 193 IP1/M1 +--------+ | DGW1 194 +---------+ +-------------+ 195 | |----|(EVI-10) | 196 SN1---+ NVE2 | | | IRB1 | 197 | +--------+ | | | (VRF)|---+ 198 SN2---TS2(VA)--|(EVI-10)|----| | +-------------+ _|_ 199 | IP2/M2 +--------+ | VXLAN/ | ( ) 200 IP4---+ <-+ | nvGRE | DGW2 ( WAN ) 201 | | | +-------------+ (___) 202 vIP23 (floating) | |----|(EVI-10) | | 203 | +---------+ | IRB2 | | 204 SN1---+ <-+ NVE3 | | | | (VRF)|---+ 205 | IP3/M3 +--------+ | | | +-------------+ 206 SN3---TS3(VA)--|(EVI-10)|------+ | | 207 | +--------+ | | 208 IP5---+ | | 209 | | 210 NVE4 | | NVE5 +--SN5 211 +---------------------+ | | +--------+ | 212 IP6------|(EVI-1) | | +----|(EVI-10)|--TS4(VA)--SN6 213 | \ IRB3 | | +--------+ | 214 | (VRF)-(EVI-10)|--+ ESI4 +--SN7 215 | / | 216 |---|(EVI-2) | 217 SN4| +---------------------+ 219 Figure 1 DC inter-subnet use-cases 221 Where: 223 NVE1, NVE2, NVE3, NVE4, NVE5, DGW1 and DGW2 share the same EVI for a 224 particular tenant. EVI-10 is the corresponding EVPN MAC-VRF for the 225 shared EVI on each element, i.e. core-facing EVI, and all the hosts 226 connected to that instance belong to the same IP subnet. The hosts 227 connected to EVI-10 are listed below: 229 o TS1 is a VM that generates/receives traffic from/to IP1, where 230 IP1 belongs to the EVI-10 subnet. 232 o TS2 and TS3 are Virtual Appliances (VA) that generate/receive 233 traffic from/to the subnets and hosts seating behind them 234 (SN1, SN2, SN3, IP4 and IP5). Their IP addresses (IP2 and IP3) 235 belong to the EVI-10 subnet and they can also generate/receive 236 traffic. When these VAs receive packets destined to their own 237 MAC addresses (M2 and M3) they will route the packets to the 238 proper subnet or host. These VAs do not support routing 239 protocols to advertise the subnets connected to them and can 240 move to a different server and NVE when the Cloud Management 241 System decides to do so. These VAs may also support redundancy 242 mechanisms for some subnets, similar to VRRP, where a floating 243 IP is owned by the master VA and only the master VA forwards 244 traffic to a given subnet. E.g.: vIP23 in figure 1 is a 245 floating IP that can be owned by TS2 or TS3 depending on who 246 the master is. Only the master will forward traffic to SN1. 248 o Integrated Routing and Bridging interfaces IRB1, IRB2 and IRB3 249 have their own IP addresses that belong to the EVI-10 subnet 250 too. These IRB interfaces connect the EVI-10 subnet to Virtual 251 Routing and Forwarding (VRF) instances that can route the 252 traffic to other connected subnets for the same tenant (within 253 the DC or at the other end of the WAN). 255 o TS4 is a layer-2 VA that provides connectivity to subnets SN5, 256 SN6 and SN7, but does not have an IP address itself in the 257 EVI-10. TS4 is connected to a physical port on NVE5 assigned 258 to Ethernet Segment Identifier 4. 260 All the above DC use cases require inter-subnet forwarding and 261 therefore the individual host routes and subnets MUST be advertised: 263 a) From the NVEs (since VAs and VMs do not run routing protocols) and 264 b) Associated to an overlay next-hop that can be a VA IP address, a 265 floating IP address, and IRB IP address or an ESI. 267 2.2 The requirement for advertising IP prefixes in EVPN 269 In all the inter-subnet connectivity cases discussed in section 2.1 270 there is a need to advertise IP prefixes in the control plane. The 271 advertisement of such prefixes must meet certain requirements, 272 specific to NVO-based Data Centers: 274 o The data plane in NVO-based Data Centers is not based on IP 275 over a GRE or MPLS tunnel as required by [RFC4364], but 276 Ethernet over an IP tunnel, such as VXLAN or NVGRE. 278 o The IP prefixes in the DC must be advertised with a 279 flexibility that does not exist in IP-VPNs today. For 280 instance: 282 a) The advertised overlay next-hop for a given IP prefix can 283 be an IRB IP address (see section 5.3), a floating IP 284 address (see section 5.2) or even an ESI (see section 5.4). 286 b) VXLAN or NVGRE virtual identifiers can have a global or a 287 local scope. The implementation MUST support the flexibility 288 to advertise IP Prefixes associated to a global identifier 289 (32-bit value encoded in the EVPN Ethernet Tag ID) or a 290 locally significant identifier (20-bit value encoded in the 291 MPLS label field). At the moment, [RFC4364] can only 292 advertise Prefixes associated to a locally significant 293 identifier (MPLS label). 295 c) Since an NVE can potentially advertise many Prefixes with 296 different overlay next-hops and different VXLAN/NVGRE 297 identifiers, it is highly desirable to be able to advertise 298 those prefixes with their corresponding overlay next-hops 299 and VXLAN/NVGRE identifiers as attributes within the same 300 NLRI, for a better BGP update packing. [RFC4364] does not 301 have the capability of advertising a flexible overlay next- 302 hop together with a prefix in the same NLRI. 304 o IP prefixes must be advertised by NVE devices that have no VRF 305 instances defined and no capability to process IP-VPN 306 prefixes. These NVE devices just support EVPN and advertise IP 307 Prefixes on behalf of some connected Tenant Systems. In other 308 words: any attempt to solve this problem by simply using 309 [RFC4364] routes requires that any EVPN deployment must be 310 accompanied with a concurrent IP-VPN topology, which is not 311 possible in most of the cases. 313 o Finally, Data Center providers want to use a single BGP 314 Subsequent Address Family (AFI/SAFI) for the advertisement of 315 addresses within the Data Center, i.e. BGP EVPN only, as 316 opposed to using EVPN and IP-VPN in a concurrent topology. 317 This minimizes the control plane overhead in TORs and 318 Hypervisors and simplifies the operations. 320 EVPN is extended - as described in this document - to advertise IP 321 prefixes with the flexibility required by the current and future Data 322 Center applications. 324 2.3 The requirement for a new EVPN route type 326 [EVPN] defines a MAC/IP route (or RT-2) where a MAC address can be 327 advertised together with an IP address length (IPL) and IP address 328 (IP). While a variable IPL might be used to indicate the presence of 329 an IP prefix in a route type 2, there are several specific use cases 330 in which using this route type to deliver IP Prefixes is not 331 suitable. 333 One example of such use cases is the "floating IP" example described 334 in section 2.1. In this example we need to decouple the advertisement 335 of the prefixes from the advertisement of the floating IP (vIP23 in 336 figure 1) and MAC associated to it, otherwise the solution gets 337 highly inefficient and does not scale. 339 E.g.: if we are advertising 1k prefixes from M2 (using route type 2) 340 and the floating IP owner changes from M2 to M3, we would need to 341 withdraw 1k routes from M2 and re-advertise 1k routes from M3. 342 However if we use a separate route type, we can advertise the 1k 343 routes associated to the floating IP address (vIP23) and only one 344 route type 2 for advertising the ownership of the floating IP, i.e. 345 vIP23 and M2 in the route type 2. When the floating IP owner changes 346 from M2 to M3, a single route type 2 withdraw/update is required to 347 indicate the change. The remote DGW will not change any of the 1k 348 prefixes associated to vIP23, but will only update the ARP resolution 349 entry for vIP23 (now pointing at M3). 351 Other reasons to decouple the IP Prefix advertisement from the MAC 352 route are listed below: 354 o Clean identification, operation of troubleshooting of IP 355 Prefixes, not subject to interpretation and independent of the 356 IPL and the IP value. E.g.: a default IP route 0.0.0.0/0 must 357 always be easily and clearly distinguished from the absence of 358 IP information. 360 o MAC address information must not be compared by BGP when 361 selecting two IP Prefix routes. If IP Prefixes are to be 362 advertised using MAC routes, the MAC information is always 363 present and part of the route key. 365 o IP Prefix routes must not be subject to MAC route procedures 366 such as MAC Mobility or aliasing. Prefixes advertised from two 367 different ESIs do not mean mobility; MACs advertised from two 368 different ESIs do mean mobility. Similarly load balancing for 369 IP prefixes is achieved through IP mechanisms such as ECMP, 370 and not through MAC route mechanisms such as aliasing. 372 o NVEs that do not require processing IP Prefixes must have an 373 easy way to identify an update with an IP Prefix and ignore 374 it, rather than processing the MAC route only to find out 375 later that it carries a Prefix that must be ignored. 377 The following sections describe how EVPN is extended with a new route 378 type for the advertisement of prefixes and how this route is used to 379 address the current and future inter-subnet connectivity requirements 380 existing in the Data Center. 382 3. The BGP EVPN IP Prefix route 384 The current BGP EVPN NLRI as defined in [EVPN] is shown below: 386 +-----------------------------------+ 387 | Route Type (1 octet) | 388 +-----------------------------------+ 389 | Length (1 octet) | 390 +-----------------------------------+ 391 | Route Type specific (variable) | 392 +-----------------------------------+ 394 Where the route type field can contain one of the following specific 395 values: 397 + 1 - Ethernet Auto-Discovery (A-D) route 399 + 2 - MAC advertisement route 401 + 3 - Inclusive Multicast Route 403 + 4 - Ethernet Segment Route 405 This document defines an additional route type that will be used for 406 the advertisement of IP Prefixes: 408 + 5 - IP Prefix Route 410 The support for this new route type is OPTIONAL. 412 Since this new route type is OPTIONAL, an implementation not 413 supporting it MUST ignore the route, based on the unknown route type 414 value. 416 The detailed encoding of this route and associated procedures are 417 described in the following sections. 419 3.1 IP Prefix Route encoding 421 An IP Prefix advertisement route type specific EVPN NLRI consists of 422 the following fields: 424 +---------------------------------------+ 425 | RD (8 octets) | 426 +---------------------------------------+ 427 |Ethernet Segment Identifier (10 octets)| 428 +---------------------------------------+ 429 | Ethernet Tag ID (4 octets) | 430 +---------------------------------------+ 431 | IP Address Length (1 octet) | 432 +---------------------------------------+ 433 | IP Address (4 or 16 octets) | 434 +---------------------------------------+ 435 | GW IP Address (4 or 16 octets) | 436 +---------------------------------------+ 437 | MPLS Label (3 octets) | 438 +---------------------------------------+ 440 Where: 442 o RD, Ethernet Tag ID and MPLS Label fields will be used as 443 defined in [EVPN] and [EVPN-OVERLAYS]. 445 o The Ethernet Segment Identifier will be a non-zero 10-byte 446 identifier if the ESI is used as an overlay next-hop. It will 447 be zero otherwise. 449 o The IP address length can be set to a value between 0 and 32 450 (bits) for ipv4 and between 0 and 128 for ipv6. 452 o The IP address will be a 32 or 128-bit field (ipv4 or ipv6). 454 o The GW IP (Gateway IP Address) will be a 32 or 128-bit field 455 (ipv4 or ipv6), and will encode the overlay IP next-hop for 456 the IP Prefixes. The GW IP field can be zero if it is not used 457 as an overlay next-hop. 459 o The total route length will indicate the type of prefix (ipv4 460 or ipv6) and the type of GW IP address (ipv4 or ipv6). Note 461 that the IP Address + the GW IP should have a length of either 462 64 or 256 bits, but never 160 bits (ipv4 and ipv6 mixed values 463 are not allowed). 465 The Eth-Tag ID, IP address length and IP address will be part of the 466 route key used by BGP to compare routes. The rest of the fields will 467 be out of the route key. 469 The route will contain a single overlay next-hop, i.e. if the ESI 470 field is zero, the GW IP field will not, and vice versa. The 471 following table shows the different inter-subnet use-cases described 472 in this document and the corresponding coding of the overlay next-hop 473 in the route-type 5 (RT-5). 475 +----------------------------+----------------------------------+ 476 | Overlay next-hop use-case | Field in the RT-5 | 477 +----------------------------+----------------------------------+ 478 | TS IP address | GW IP Address | 479 | Floating IP address | GW IP Address | 480 | IRB IP address | GW IP Address | 481 | "Bump in the wire" | ESI | 482 | VRF-to-VRF | GW MAC Address (Tunnel Attribute)| 483 +----------------------------+----------------------------------+ 485 4. Benefits of using the EVPN IP Prefix route 487 This section clarifies the different functions accomplished by the 488 EVPN RT-2 and RT-5 routes, and provides a list of benefits derived 489 from using a separate route type for the advertisement of IP Prefixes 490 in EVPN. 492 [EVPN] describes the content of the BGP EVPN route type 2 specific 493 NLRI, i.e. MAC/IP Advertisement Route, where the IP address length 494 (IPL) and IP address (IP) of a specific advertised MAC are encoded. 495 The subject of the MAC advertisement route is the MAC address (M) and 496 MAC address length (ML) encoded in the route. The MAC mobility and 497 other complex procedures are defined around that MAC address. The IP 498 address information carries the host IP address required for the ARP 499 resolution of the MAC according to [EVPN] and and the host route to 500 be programmed in the IP-VRF [EVPN-INTERSUBNET]. 502 The BGP EVPN route type 5 defined in this document, i.e. IP Prefix 503 Advertisement route, decouples the advertisement of IP prefixes from 504 the advertisement of any MAC address related to it. This brings some 505 major benefits to NVO-based networks where certain inter-subnet 506 forwarding scenarios are required. Some of those benefits are: 508 a) Upon receiving a route type 2 or type 5, an egress NVE can easily 509 distinguish MACs and IPs from IP Prefixes. E.g. an IP prefix with 510 IPL=32 being advertised from two different ingress NVEs (as RT-5) 511 can be identified as such and be imported in the designated 512 routing context as two ECMP routes, as opposed to two MACs 513 competing for the same IP. 515 b) Similarly, upon receiving a route, an egress NVE not supporting 516 processing IP Prefixes can easily ignore the update, based on the 517 route type. 519 c) A MAC route includes the ML, M, IPL and IP in the route key that 520 is used by BGP to compare routes, whereas for IP Prefix routes, 521 only IPL and IP (as well as Ethernet Tag ID) are part of the route 522 key. Advertised IP Prefixes are imported into the designated 523 routing context, where there is no MAC information associated to 524 IP routes. In the example illustrated in figure 1, subnet SN1 525 should be advertised by NVE2 and NVE3 and interpreted by DGW1 as 526 the same route coming from two different next-hops, regardless of 527 the MAC address associated to TS2 or TS3. This is easily 528 accomplished in the route type 5 by including only the IP 529 information in the route key. 531 d) By decoupling the MAC from the IP Prefix advertisement procedures, 532 we can leave the IP prefix advertisements out of the MAC mobility 533 procedures defined in [EVPN] for MACs. In addition, this allows us 534 to have an indirection mechanism for IP prefixes advertised from a 535 MAC/IP that can move between hypervisors. E.g. if there are 1,000 536 prefixes seating behind TS2 (figure 1), NVE2 will advertise all 537 those prefixes in RT-5 routes associated to the next-hop IP2. 538 Should TS2 move to a different NVE, a single MAC advertisement 539 route withdraw for the M2/IP2 route from NVE2 will invalidate the 540 1,000 prefixes, as opposed to have to wait for each individual 541 prefix to be withdrawn. This may be easily accomplished by using 542 IP Prefix routes that are not tied to a MAC address, and use a 543 different MAC route to advertise the location and resolution of 544 the overlay next-hop to a MAC address. 546 5. IP Prefix next-hop use-cases 548 The IP Prefix route can use a GW IP, an ESI or a GW MAC as an overlay 549 next-hop. This section describes some use-cases for these next-hop 550 types. 552 5.1 TS IP address next-hop use-case 554 The following figure illustrates an example of inter-subnet 555 forwarding for subnets seating behind Virtual Appliances (on TS2 and 556 TS3). 558 SN1---+ NVE2 DGW1 559 | +--------+ +---------+ +-------------+ 560 SN2---TS2(VA)--|(EVI-10)|----| |----|(EVI-10) | 561 | IP2/M2 +--------+ | | | IRB1\ | 562 IP4---+ | | | (VRF)|---+ 563 | | +-------------+ _|_ 564 | VXLAN/ | ( ) 565 | nvGRE | DGW2 ( WAN ) 566 SN1---+ NVE3 | | +-------------+ (___) 567 | IP3/M3 +--------+ | |----|(EVI-10) | | 568 SN3---TS3(VA)--|(EVI-10)|----| | | IRB2\ | | 569 | +--------+ +---------+ | (VRF)|---+ 570 IP5---+ +-------------+ 572 Figure 2 TS IP address use-case 574 An example of inter-subnet forwarding between subnet SN1/24 and a 575 subnet seating in the WAN is described below. NVE2, NVE3, DGW1 and 576 DGW2 are running BGP EVPN. TS2 and TS3 do not support routing 577 protocols, only a static route to forward the traffic to the WAN. 579 (1) NVE2 advertises the following BGP routes on behalf of TS2: 581 o Route type 2 (MAC route) containing: ML=48, M=M2, IPL=32, 582 IP=IP2 584 o Route type 5 (IP Prefix route) containing: IPL=24, IP=SN1, 585 ESI=0, GW IP address=IP2 587 (2) NVE3 advertises the following BGP routes on behalf of TS3: 589 o Route type 2 (MAC route) containing: ML=48, M=M3, IPL=32, 590 IP=IP3 592 o Route type 5 (IP Prefix route) containing: IPL=24, IP=SN1, 593 ESI=0, GW IP address=IP3 595 (3) DGW1 and DGW2 import both received routes based on the RT: 597 o Based on the EVI-10 route-target in DGW1 and DGW2, the MAC 598 route is imported and M2 is added to the EVI-10 MAC-VRF along 599 with its corresponding tunnel information. For the VXLAN use 600 case, the VTEP will be derived from the MAC route BGP next-hop 601 (underlay next-hop) and VNI from the Ethernet Tag or MPLS 602 fields. IP2 - M2 is added to the ARP table. 604 o Based on the EVI-10 route-target in DGW1 and DGW2, the IP 605 Prefix route is also imported and SN1/24 is added to the 606 designated routing context with next-hop IP2 pointing at the 607 local EVI-10. Should ECMP be enabled in the routing context, 608 SN1/24 would also be added to the routing table with next-hop 609 IP3. 611 (4) When DGW1 receives a packet from the WAN with destination IPx, 612 where IPx belongs to SN1/24: 614 o A destination IP lookup is performed on the DGW1 VRF routing 615 table and next-hop=IP2 is found. The tunnel information to 616 encapsulate the packet will be derived from the route-type 2 617 (MAC route) received for M2/IP2. 619 o IP2 is resolved to M2 in the ARP table, and M2 is resolved to 620 the tunnel information given by the MAC FIB (remote VTEP and 621 VNI for the VXLAN case). 623 o The IP packet destined to IPx is encapsulated with: 625 . Source inner MAC = IRB1 MAC 627 . Destination inner MAC = M2 629 . Tunnel information provided by the MAC-VRF (VNI, VTEP IPs 630 and MACs for the VXLAN case) 632 (5) When the packet arrives at NVE2: 634 o Based on the tunnel information (VNI for the VXLAN case), the 635 EVI-10 context is identified for a MAC lookup. 637 o Encapsulation is stripped-off and based on a MAC lookup 638 (assuming MAC forwarding on the egress NVE), the packet is 639 forwarded to TS2, where it will be properly routed. 641 (6) Should TS2 move from NVE2 to NVE3, MAC Mobility procedures will 642 be applied to the MAC route IP2/M2, as defined in [EVPN]. Route type 643 5 prefixes are not subject to MAC mobility procedures, hence no 644 changes in the DGW VRF routing table will occur for TS2 mobility, 645 i.e. all the prefixes will still be pointing at IP2 as next-hop. 646 There is an indirection for e.g. SN1/24, which still points at 647 next-hop IP2 in the routing table, but IP2 will be simply resolved to 648 a different tunnel, based on the outcome of the MAC mobility 649 procedures for the MAC route IP2/M2. 651 Note that in the opposite direction, TS2 will send traffic based on 652 its static-route next-hop information (IRB1 and/or IRB2), and regular 653 EVPN procedures will be applied. 655 5.2 Floating IP next-hop use-case 657 Sometimes Tenant Systems (TS) work in active/standby mode where an 658 upstream floating IP - owned by the active TS - is used as the next- 659 hop to get to some subnets behind. This redundancy mode, already 660 introduced in section 2.1 and 2.3, is illustrated in Figure 3. 662 NVE2 DGW1 663 +--------+ +---------+ +-------------+ 664 +---TS2(VA)--|(EVI-10)|----| |----|(EVI-10) | 665 | IP2/M2 +--------+ | | | IRB1\ | 666 | <-+ | | | (VRF)|---+ 667 | | | | +-------------+ _|_ 668 SN1 vIP23 (floating) | VXLAN/ | ( ) 669 | | | nvGRE | DGW2 ( WAN ) 670 | <-+ NVE3 | | +-------------+ (___) 671 | IP3/M3 +--------+ | |----|(EVI-10) | | 672 +---TS3(VA)--|(EVI-10)|----| | | IRB2\ | | 673 +--------+ +---------+ | (VRF)|---+ 674 +-------------+ 675 Figure 3 Floating IP next-hop for redundant TS 677 In this example, assuming TS2 is the active TS and owns IP23: 679 (1) NVE2 advertises the following BGP routes for TS2: 681 o Route type 2 (MAC route) containing: ML=48, M=M2, IPL=32, 682 IP=IP23 684 o Route type 5 (IP Prefix route) containing: IPL=24, IP=SN1, 685 ESI=0, GW IP address=IP23 687 (2) NVE3 advertises the following BGP routes for TS3: 689 o Route type 5 (IP Prefix route) containing: IPL=24, IP=SN1, 690 ESI=0, GW IP address=IP23 692 (3) DGW1 and DGW2 import both received routes based on the RT: 694 o M2 is added to the EVI-10 MAC FIB along with its corresponding 695 tunnel information. For the VXLAN use case, the VTEP will be 696 derived from the MAC route BGP next-hop and VNI from the 697 Ethernet Tag or MPLS fields. IP23 - M2 is added to the ARP 698 table. 700 o SN1/24 is added to the designated routing context in DGW1 and 701 DGW2 with next-hop IP23 pointing at the local EVI-10. 703 (4) When DGW1 receives a packet from the WAN with destination IPx, 704 where IPx belongs to SN1/24: 706 o A destination IP lookup is performed on the DGW1 IP-VRF 707 routing table and next-hop=IP23 is found. The tunnel 708 information to encapsulate the packet will be derived from the 709 route-type 2 (MAC route) received for M2/IP23. 711 o IP23 is resolved to M2 in the ARP table, and M2 is resolved to 712 the tunnel information given by the MAC-VRF (remote VTEP and 713 VNI for the VXLAN case). 715 o The IP packet destined to IPx is encapsulated with: 717 . Source inner MAC = IRB1 MAC 719 . Destination inner MAC = M2 721 . Tunnel information provided by the MAC FIB (VNI, VTEP IPs 722 and MACs for the VXLAN case) 724 (5) When the packet arrives at NVE2: 726 o Based on the tunnel information (VNI for the VXLAN case), the 727 EVI-10 context is identified for a MAC lookup. 729 o Encapsulation is stripped-off and based on a MAC lookup 730 (assuming MAC forwarding on the egress NVE), the packet is 731 forwarded to TS2, where it will be properly routed. 733 (6) When the redundancy protocol running between TS2 and TS3 appoints 734 TS3 as the new active TS for SN1, TS3 will now own the floating IP23 735 and will signal this new ownership (GARP message or similar). Upon 736 receiving the new owner's notification, NVE3 will issue a route type 737 2 for M3-IP23. DGW1 and DGW2 will update their ARP tables with the 738 new MAC resolving the floating IP. No changes are carried out in the 739 VRF routing table. 741 In the DGW1/2 BGP RIB, there will be two route type 5 routes for SN1 742 (from NVE2 and NVE3) but only the one with the same BGP next-hop as 743 the IP23 route type 2 BGP next-hop will be valid. 745 5.3 IRB IP next-hop use-case 747 In some other cases, the NVEs and DGWs will have just IRB interfaces 748 as hosts in the EVPN instance. This use-case is referred as "IRB 749 forwarding on NVEs with core-facing IRB Interface" in [EVPN- 750 INTERSUBNET], however the new requirement here is the advertisement 751 of IP Prefixes as opposed to only host routes. Figure 4 illustrates 752 an example. 754 NVE1 755 +---------------------+ DGW1 756 IP1---|(EVI-1) | +-------------+ 757 | \ IRB3 | +---------+ |(EVI-10) | 758 | (VRF)-(EVI-10)|--| |--| IRB1\ | 759 | / | | | | (VRF)|---+ 760 |-|(EVI-2) | | | +-------------+ _|_ 761 SN1| +---------------------+ | | ( ) 762 | +---------------------+ | VXLAN/ | DGW2 ( WAN ) 763 |-|(EVI-2) | | nvGRE | +-------------+ (___) 764 | \ IRB4 | | | |(EVI-10) | | 765 | (VRF)-(EVI-10)|--| |--| IRB2\ | | 766 | / | +---------+ | (VRF)|---+ 767 SN2---|(EVI-3) | +-------------+ 768 +---------------------+ 769 NVE2 771 Figure 4 IRB IP next-hop use-case 773 In this case: 775 (1) NVE1 advertises the following BGP routes for SN1 resolution: 777 o Route type 2 (MAC route) containing: ML=48, M=IRB3-MAC, 778 IPL=32, IP=IRB3-IP 780 o Route type 5 (IP Prefix route) containing: IPL=24, IP=SN1, 781 ESI=0, GW IP address=IRB3-IP 783 (2) NVE2 advertises the following BGP routes for SN1 resolution: 785 o Route type 2 (MAC route) containing: ML=48, M=IRB4-MAC, 786 IPL=32, IP=IRB4-IP 788 o Route type 5 (IP Prefix route) containing: IPL=24, IP=SN1, 789 ESI=0, GW IP address=IRB4-IP 791 (3) DGW1 and DGW2 import both received routes based on the RT: 793 o IRB3-MAC and IRB4-MAC are added to the EVI-10 MAC-VRF along 794 with their corresponding tunnel information. For the VXLAN use 795 case, the VTEP will be derived from the MAC route BGP next-hop 796 and VNI from the Ethernet Tag or MPLS fields. IRB3-MAC - IRB3- 797 IP and IRB4-MAC - IRB4-IP are added to the ARP table. 799 o SN1/24 is added to the designated routing context in DGW1 and 800 DGW2 with next-hop IRB3-IP (and/or IRB4-IP) pointing at the 801 local EVI-10. 803 Similar forwarding procedures as the ones described in the previous 804 use-cases are followed. 806 5.4 ESI next-hop ("Bump in the wire") use-case 808 The following figure illustrates and example of inter-subnet 809 forwarding for a subnet route that uses an ESI as an overlay next- 810 hop. In this use-case, TS2 and TS3 are layer-2 VA devices without any 811 IP address that can be included as an overlay next-hop in the GW IP 812 field of the IP Prefix route. 814 NVE2 DGW1 815 +--------+ +---------+ +-------------+ 816 +---TS2(VA)--|(EVI-10)|----| |----|(EVI-10) | 817 | ESI23 +--------+ | | | IRB1 | 818 | + | | | (VRF)|---+ 819 | | | | +-------------+ _|_ 820 SN1 | | VXLAN/ | ( ) 821 | | | nvGRE | DGW2 ( WAN ) 822 | + NVE3 | | +-------------+ (___) 823 | ESI23 +--------+ | |----|(EVI-10) | | 824 +---TS3(VA)--|(EVI-10)|----| | | IRB2 | | 825 +--------+ +---------+ | (VRF)|---+ 826 +-------------+ 828 Figure 5 ESI next-hop use-case 830 Since neither TS2 nor TS3 can run any routing protocol and have no IP 831 address assigned, an ESI, i.e. ESI23, will be provisioned on the 832 attachment ports of NVE2 and NVE3. This model supports VA redundancy 833 in a similar way as the one described in section 4.2 for the floating 834 IP next-hop use-case, only using the EVPN A-D route instead of the 835 MAC advertisement route to advertise the location of the overlay 836 next-hop. The procedure is explained below: 838 (1) NVE2 advertises the following BGP routes for TS2: 840 o Route type 1 (A-D route for EVI-10) containing: ESI=ESI23 and 841 the corresponding tunnel information (Ethernet Tag and/or MPLS 842 label). Assuming the ESI is active on NVE2, NVE2 will 843 advertise this route. 845 o Route type 5 (IP Prefix route) containing: IPL=24, IP=SN1, 846 ESI=ESI23, GW IP address=0. 848 (2) NVE3 advertises the following BGP routes for TS3: 850 o Route type 1 (A-D route for EVI-10) containing: ESI=ESI23 and 851 the corresponding tunnel information (Ethernet Tag and/or MPLS 852 label). NVE3 will advertise this route assuming the ESI is 853 active on NVE2. Note that if the resiliency mechanism for TS2 854 and TS3 is in active-active mode, both NVE2 and NVE3 will send 855 the A-D route. Otherwise, that is, the resiliency is active- 856 standby, only the NVE owning the active ESI will advertise the 857 A-D route for ESI23. 859 o Route type 5 (IP Prefix route) containing: IPL=24, IP=SN1, 860 ESI=23, GW IP address=0. 862 (3) DGW1 and DGW2 import the received routes based on the RT: 864 o The tunnel information to get to ESI23 is installed in DGW1 865 and DGW2. For the VXLAN use case, the VTEP will be derived 866 from the A-D route BGP next-hop and VNI from the Ethernet Tag 867 or MPLS fields (see [EVPN-OVERLAYS]). 869 o SN1/24 is added to the designated routing context in DGW1 and 870 DGW2 with next-hop ESI23 pointing at the local EVI-10. 872 (4) When DGW1 receives a packet from the WAN with destination IPx, 873 where IPx belongs to SN1/24: 875 o A destination IP lookup is performed on the DGW1 VRF routing 876 table and next-hop=ESI23 is found. The tunnel information to 877 encapsulate the packet will be derived from the route-type 1 878 (A-D route) received for ESI23. 880 o The IP packet destined to IPx is encapsulated with: 882 . Source inner MAC = IRB1 MAC 884 . Destination inner MAC = M2 (this MAC will be obtained 885 after a looked up in the VRF ARP table or in the EVI-10 886 FDB table associated to ESI23). 888 . Tunnel information provided by the A-D route for ESI23 889 (VNI, VTEP IP and MACs for the VXLAN case). 891 (5) When the packet arrives at NVE2: 893 o Based on the tunnel information (VNI for the VXLAN case), the 894 EVI-10 context is identified for a MAC lookup (assuming MAC 895 disposition model). 897 o Encapsulation is stripped-off and based on a MAC lookup 898 (assuming MAC forwarding on the egress NVE), the packet is 899 forwarded to TS2, where it will be properly forwarded. 901 (6) If the redundancy protocol running between TS2 and TS3 follows an 902 active/standby model and there is a failure, appointing TS3 as the 903 new active TS for SN1, TS3 will now own the connectivity to SN1 and 904 will signal this new ownership (GARP message or similar). Upon 905 receiving the new owner's notification, NVE3 will issue a route type 906 1 for ESI23, whereas NVE2 will withdraw it's A-D route for ESI23. 907 DGW1 and DGW2 will update their tunnel information to resolve ESI23. 908 No changes are carried out in the VRF routing table. 910 In the DGW1/2 BGP RIB, there will be two route type 5 routes for SN1 911 (from NVE2 and NVE3) but only the one with the same BGP next-hop as 912 the ESI23 route type 1 BGP next-hop will be valid. 914 5.5 IRB forwarding without core-facing IRB use-case (VRF-to-VRF) 916 This use-case is referred as "IRB forwarding on NVEs without core- 917 facing IRB Interface" in [EVPN-INTERSUBNET], however the new 918 requirement here is the advertisement of IP Prefixes as opposed to 919 only host routes. In the previous examples, the EVI instance can 920 connect IRB interfaces and any other Tenant Systems connected to it. 921 EVPN provides connectivity for: 923 a) Traffic destined to the IRB IP interfaces as well as 925 b) Traffic destined to IP subnets seating behind the IRB interfaces, 926 e.g. SN1 or SN2. 928 In order to provide connectivity for (a) we need MAC/IP routes (RT-2) 929 distributing IRB MACs and IPs. Connectivity type (b) is accomplished 930 by the exchange of IP Prefix routes (route type 5) for IPs and 931 subnets seating behind IRBs. 933 In some cases, connectivity type (a) (see above) is not required and 934 the EVI instance is connecting only IRB interfaces, which are never 935 the final destination of any packet. This use case is depicted in the 936 diagram below and we refer to it as the "IRB forwarding on NVEs 937 without core-facing IRB Interface" use-case: 939 NVE1 940 +------------+ 941 IP1-----|(EVI-1) | DGW1 942 | \ | +---------+ +-----+ 943 | (VRF)|----| |----|(VRF)|----+ 944 | / | | | +-----+ | 945 |---|(EVI-2) | | | _|_ 946 | +------------+ | | ( ) 947 SN1| | VXLAN/ | ( WAN ) 948 | NVE2 | nvGRE | (___) 949 | +------------+ | | | 950 |---|(EVI-2) | | | DGW2 | 951 | \ | | | +-----+ | 952 | (VRF)|----| |----|(VRF)|----+ 953 | / | +---------+ +-----+ 954 SN2-----|(EVI-3) | 955 +------------+ 957 Figure 6 Inter-subnet forwarding without core-facing IRB interfaces 959 In this case, we need to provide connectivity from/to IP hosts in 960 SN1, SN2, IP1 and hosts seating at the other end of the WAN. The EVI 961 in the core just connects all the IRBs in NVE1, NVE2, DGW1 and DGW2 962 but there will not be any IP host in this core EVI that is the final 963 destination of any IP packet. 965 Therefore there is no need to define IRB interfaces (IRBs are not 966 represented in the diagram). This is the reason why we refer to this 967 solution as "Inter-subnet forwarding without core-facing IRB 968 interfaces" or "VRF-to-VRF" solution. 970 In this case, the proposal is to use EVPN type 5 routes and a BGP 971 tunnel encapsulation attribute as in [EVPN-INTERSUBNET], where the 972 following information is carried: 974 o Route type 5 Eth-Tag ID can contain the core instance VNI (if 975 the VNI is global, otherwise, for local significant VNIs, an 976 MPLS label field may be added with a 20-bit VNI encoded in the 977 label space). 979 o Route type 5 IP address length and IP address, as explained in 980 the previous sections. 982 o Route type 5 GW IP address=0 and ESI=0. 984 o Tunnel Encapsulation Attribute as per [EVPN-INTERSUBNET] 985 containing the following fields and including the GW MAC to be 986 used in the overlay encapsulation: 988 o Tunnel Type (2 octets) is: 990 + TBD - VXLAN Encapsulation 991 + TBD - NVGRE Encapsulation 993 o Length (2 octets): the total number of octets of the value 994 field. 996 o Address Length= 6 bytes (for MAC address) 998 o Address= GW MAC Address, a MAC address associated to the 999 system advertising the route. This MAC address identifies 1000 the NVE/DGW and can be re-used for all the IP-VRFs in the 1001 node. 1003 Example of prefix advertisement for the ipv4 prefix SN1/24 advertised 1004 from NVE1: 1006 (1) NVE1 advertises the following BGP route for SN1: 1008 o Route type 5 (IP Prefix route) containing: Eth-Tag=VNI=10 1009 (assuming global VNI), IPL=24, IP=SN1. In addition to that, a 1010 Tunnel Encapsulation Attribute will be sent, where: Tunnel-type= 1011 VXLAN or NVGRE, and the address value will contain a GW MAC 1012 address= NVE1 MAC. 1014 (2) DGW1 imports the received route from NVE1 and SN1/24 is added to 1015 the designated routing context. The next-hop for SN1/24 will be given 1016 by the route type 5 BGP next-hop (NVE1), which is resolved to a 1017 tunnel. For instance: if the tunnel is VXLAN based, the BGP next-hop 1018 will be resolved to a VXLAN tunnel where: destination-VTEP= NVE1 IP, 1019 VNI=10, inner destination MAC = NVE1 MAC (derived from the GW MAC 1020 value in the Tunnel Encapsulation attribute). 1022 (3) When DGW1 receives a packet from the WAN with destination IPx, 1023 where IPx belongs to SN1/24: 1025 o A destination IP lookup is performed on the DGW1 VRF routing table 1026 and next-hop= "NVE1 IP" is found. The tunnel information to 1027 encapsulate the packet will be derived from the route-type 5 1028 received for SN1. 1030 o The IP packet destined to IPx is encapsulated with: Source inner 1031 MAC = DGW1 MAC, Destination inner MAC = NVE1 MAC, Source outer IP 1032 (source VTEP) = DGW1 IP, Destination outer IP (destination VTEP) = 1033 NVE1 IP 1035 (4) When the packet arrives at NVE1: 1037 o Based on the tunnel information (VNI for the VXLAN case), the 1038 routing context is identified for an IP lookup. 1040 o An IP lookup is performed in the routing context, where SN1 turns 1041 out to be a local subnet associated to EVI-2. A subsequent lookup 1042 in the ARP table and the EVI-2 MAC-VRF will return the forwarding 1043 information for the packet in EVI-2. 1045 6. Conclusions 1047 A new EVPN route type 5 for the advertisement of IP Prefixes is 1048 proposed in this document. This new route type will have a 1049 differentiated role from the RT-2 route and will address all the Data 1050 Center (or NVO-based networks in general) inter-subnet connectivity 1051 scenarios in which IP Prefix advertisement is required. Using this 1052 new RT-5 route, an IP Prefix will be advertised along with an overlay 1053 next-hop that can be a GW IP address, an ESI or a GW MAC address. As 1054 discussed throughout the document, IP-VPN cannot address all the 1055 inter-subnet use-cases in an NVO-based DC and the existing EVPN RT-2 1056 does not meet the requirements for all the DC use cases, therefore a 1057 new EVPN route type is required. 1059 This new EVPN route type 5 decouples the IP Prefix advertisements 1060 from the MAC route advertisements in EVPN, hence: 1062 a) Allows the clean and clear announcements of ipv4 or ipv6 prefixes 1063 in an NLRI with no MAC addresses in the route key, so that only IP 1064 information is used in BGP route comparisons. 1066 b) Since the route type is different from the MAC/IP advertisement 1067 route, the advertisement of prefixes will be excluded from all the 1068 procedures defined for the advertisement of VM MACs, e.g. MAC 1069 Mobility or aliasing. As a result of that, the current EVPN 1070 procedures do not need to be modified. 1072 c) Allows a flexible implementation where the prefix can be linked to 1073 different types of next-hops: MAC address, IP address, IRB IP 1074 address, ESI, etc. and these MAC or IP addresses do not need to 1075 reside in the advertising NVE. 1077 d) An EVPN implementation not requiring IP Prefixes can simply 1078 discard them by looking at the route type value. An unknown route 1079 type MUST be ignored by the receiving NVE/PE. 1081 7. Conventions used in this document 1083 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL 1084 NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" 1085 in this document are to be interpreted as described in RFC-2119 1086 [RFC2119]. 1088 8. Security Considerations 1090 9. IANA Considerations 1092 10. References 1094 10.1 Normative References 1096 [RFC4364]Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private 1097 Networks (VPNs)", RFC 4364, February 2006. 1099 10.2 Informative References 1101 [EVPN] Sajassi et al., "BGP MPLS Based Ethernet VPN", draft-ietf- 1102 l2vpn-evpn-03.txt, work in progress, February, 2013 1104 [EVPN-OVERLAYS] Sajassi-Drake et al., "A Network Virtualization 1105 Overlay Solution using EVPN", draft-sd-l2vpn-evpn-overlay-03.txt, 1106 work in progress, June, 2014 1108 [EVPN-INTERSUBNET] Sajassi et al., "IP Inter-Subnet Forwarding in 1109 EVPN", draft-sajassi-l2vpn-evpn-inter-subnet-forwarding-04.txt, 1110 work in progress, July, 2014 1112 11. Acknowledgments 1114 The authors would like to thank Mukul Katiyar and Senthil 1115 Sathappan for their valuable feedback and contributions. 1117 12. Authors' Addresses 1119 Jorge Rabadan 1120 Alcatel-Lucent 1121 777 E. Middlefield Road 1122 Mountain View, CA 94043 USA 1123 Email: jorge.rabadan@alcatel-lucent.com 1125 Wim Henderickx 1126 Alcatel-Lucent 1127 Email: wim.henderickx@alcatel-lucent.com 1129 Florin Balus 1130 Nuage Networks 1131 Email: florin@nuagenetworks.net 1133 Aldrin Isaac 1134 Bloomberg 1135 Email: aisaac71@bloomberg.net 1137 Senad Palislamovic 1138 Alcatel-Lucent 1139 Email: senad.palislamovic@alcatel-lucent.com 1141 John E. Drake 1142 Juniper Networks 1143 Email: jdrake@juniper.net 1145 Ali Sajassi 1146 Cisco 1147 Email: sajassi@cisco.com