BESS WG Y. Wang Internet-Draft Z. Zhang Intended status: Standards Track ZTE Corporation Expires: September 17, 2020 March 16, 2020 ARP/ND Synching And IP Aliasing without IRB draft-wang-bess-evpn-arp-nd-synch-without-irb-03 Abstract This draft proposes an extension to [RFC7432] to do ARP synchronizing and IP aliasing for Layer 3 routes that is needed for EVPN signalled L3VPN to build a complete IP ECMP. The phrase "EVPN signalled L3VPN" means that there may be no MAC-VRF or IRB interface in the use case. When there are no MAC-VRF or IRB interface, EVPN signalled L3VPN is also called as pure L3VPN instance. 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 September 17, 2020. Copyright Notice Copyright (c) 2020 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 Wang & Zhang Expires September 17, 2020 [Page 1] Internet-Draft EVPN ARP/ND Synch no IRB March 2020 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 2. ARP/ND Synching and IP Aliasing . . . . . . . . . . . . . . . 4 2.1. Constructing MAC/IP Advertisement Route . . . . . . . . . 5 2.2. Constructing EAD/IP-VRF Route . . . . . . . . . . . . . . 6 2.3. Constructing EAD/ES Route . . . . . . . . . . . . . . . . 6 3. Fast Convergence for Routed Traffic . . . . . . . . . . . . . 7 4. Determining Reach-ability to Unicast IP Addresses . . . . . . 7 5. Forwarding Unicast Packets . . . . . . . . . . . . . . . . . 7 6. EVPN signalled L3VPN . . . . . . . . . . . . . . . . . . . . 8 6.1. RT-5E Advertisement on Distributed L3 GW . . . . . . . . 8 6.2. Centerlized RT-5G Advertisement for Distributed L3 Forwarding . . . . . . . . . . . . . . . . . . . . . . . 8 6.2.1. Centerlized CE-BGP . . . . . . . . . . . . . . . . . 9 6.2.2. RT-2E Advertisement from PE1/PE2 to PE3 . . . . . . . 10 6.2.3. RT-5G Advertisement from PE3 to PE1/PE2 . . . . . . . 10 6.2.4. RT-2E Advertisement between PE1 and PE2 . . . . . . . 11 6.2.5. Egress ESI Link Protection between PE1 and PE2 . . . 11 6.2.6. Comparing with Distributed RT-5G Advertisement . . . 11 6.2.7. Mass-Withdraw by EAD/ES Route . . . . . . . . . . . . 11 6.3. RT-5L Advertisement . . . . . . . . . . . . . . . . . . . 12 7. Load Balancing of Unicast Packets . . . . . . . . . . . . . . 12 8. Security Considerations . . . . . . . . . . . . . . . . . . . 12 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 10. Normative References . . . . . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 1. Introduction [I-D.sajassi-bess-evpn-ip-aliasing] proposes an extension to [RFC7432] to do aliasing for Layer 3 routes that is needed for symmetric IRB to build a complete IP ECMP. But typically there may be both IRB interfaces(to do EVPN IRB per-MAC-VRF basis) and VRF- interfaces in the same IP-VRF instance. It is necessary to apply the EVPN control-plane to the VRF-interfaces in order to support both such situations and the EVPN signalled L3VPN use case where maybe no IRB interfaces will be found in the IP-VRF instances. Wang & Zhang Expires September 17, 2020 [Page 2] Internet-Draft EVPN ARP/ND Synch no IRB March 2020 +---------+ +-------------+ | | | | | | /| PE1 |----| | +-------------+ / | | | MPLS/ | | | LAG / +-------------+ | VxLAN/ | | PE3 |---N3 N1---SW1===== | NVGRE/ | | | / \ +-------------+ | SRv6 |---| | N2 \ | | | | +-------------+ \| PE2 |----| | | | | | +-------------+ | | | | | | +---------+ Figure 1: ARP/ND Synchronizing and IP Aliasing without IRB There three CE node named N1/N2/N3 in the above network. N1/N2/N3 may be a host or a IP router. When N1/N2/N3 is a host, it is also called H1/H2/H3 in this document. When N1/N2/N3 is a router, it is also called R1/R2/R3 in this document. Consider a pair of multi-homed PEs PE1 and PE2. Let there be two hosts H1 and H2 attached to them via a L2 switch SW1. Consider another PE PE3 and a host H3 attached to it. The H1 and H2 represent subnet SN1 and the H3 represents subnet SN2. Note that it is different from [I-D.sajassi-bess-evpn-ip-aliasing] in the following aspects: There is no MAC-VRF or IRB interface on PE1/PE2/PE3. And it is the IP-VRFs that are called as EVPN instance instead. Such EVPN instance can be called pure L3 EVPN instance or L3 EVI for short. The anycast gateway of H1/H2 is configured on a sub-interface on PE1/PE2. Note that the communication between H1 and H2 won't pass through any of the multi-homed PEs. So it is not necessary for PE1/PE2 keeping a Broadcast domain and its IRB for SN1. Note that the SW1 multi-homing PE1 and PE2 via a LAG interface which maybe load-balance traffic to the PEs. This draft proposes an extension to do ARP/ND synchronizing and IP aliasing for Layer 3 routes that is needed for L3 EVI to build a complete IP ECMP. Wang & Zhang Expires September 17, 2020 [Page 3] Internet-Draft EVPN ARP/ND Synch no IRB March 2020 1.1. Terminology Most of the terminology used in this documents comes from [RFC7432] and [I-D.sajassi-bess-evpn-ip-aliasing] except for the following: VRF Interface: A interface that connects to a CE for an IP-VRF but is not an IRB interface. L3 EVI: An EVPN instance spanning the Provider Edge (PE) devices participating in that EVPN which contains VRF Interfaces and maybe contains IRB interfaces. EAD/IP-VRF: Ethernet Auto-Discovery route per IP-VRF, which differentiates itself from IP-EAD/EVI route by the MPLS label field. CE-BGP: The BGP session between PE and CE. Note that CE-BGP route doesn't have a RD or Route-Target. RMAC: Router's MAC, which is signaled in the Router's MAC extended community. RT-2E: A MAC/IP Advertisement Route with a non-reserved ESI. RT-5E: An EVPN Prefix Advertisement Route with a non-reserved ESI. RT-5G: An EVPN Prefix Advertisement Route with a zero ESI and a non- zero GW-IP. RT-5L: An EVPN Prefix Advertisement Route with both zero ESI and zero GW-IP. 2. ARP/ND Synching and IP Aliasing Host IP and MAC routes are learnt by PEs on the access side via a control plane protocol like ARP. In case where a CE is multihomed to multiple PE nodes using a LAG and is running in All-Active Redundancy Mode, the Host IP will be learnt and advertised in the MAC/IP Advertisement only by the PE that receives the ARP packet. The MAC/ IP Advertisement with non-zero ESI will be received by both PE2 and PE3. As a result, after PE2 receives the MAC/IP Advertisement and imports it to the L3 EVI, PE2 installs an ARP entry to the VRF interface whose subnet matches the IP Address from the MAC/IP Advertisement. Such ARP entry is called remote synched ARP Entry in this document. Wang & Zhang Expires September 17, 2020 [Page 4] Internet-Draft EVPN ARP/ND Synch no IRB March 2020 Note that the PEs follow [I-D.sajassi-bess-evpn-ip-aliasing] to achieve the ESI load balance except for the constructing of MAC/IP Advertisement Route and IP-EAD/EVI route. When PE3 load balance the traffic towards the multihomed Ethernet Segment, both PE1 and PE2 would have been prepared with corresponding ARP entry yet because of the ARP synching procedures. It is important to explain that typically there may be both IRB interface and VRF interface in an IP-VRF instance, which is called as the "VRF interface in EVPN IRB" use-case in this document. But each IRB/VRF interface is independent to each other in EVPN control plane. So the use-case here is constrained to a pure L3 EVPN schema, Because it is enough to describe all the control-plane updates for both the pure L3 EVPN use-case and the "VRF interface in EVPN IRB" use-case. In current EVPN control-plane for "VRF interface in EVPN IRB" use- case, the VRF interface is considered as "external link" and it just inter-operates with the EVPN control-plane. But in this document it is assumed to be better if the EVPN control-plane directly applied to the VRF interface. 2.1. Constructing MAC/IP Advertisement Route This draft introduces a new usage/construction of MAC/IP Advertisement route to enable Aliasing for IP addresses in pure L3 EVPN use-cases. The usage/construction of this route remains similar to that described in RFC 7432 with a few notable exceptions as below. * The Route-Distinguisher should be set to the corresponding L3VPN context. * The Ethernet Tag should be set to 0. * The MAC/IP Advertisement SHOULD carry one or more IP VRF Route- Target (RT) attributes. * The ESI SHOULD be set to the ESI of the VRF interface from which the ARP entry is learned. Note that the ESI is not used to install remote synched ARP entries to corresponding VRF interfaces on PE1/PE2. It is only used to load balance traffic on PE3. * The MPLS Label1 should be set to implicit-null in MPLS/SRv6 encapsulation. For VXLAN encapsulation, the MPLS label1 should be set to 0 instead. Wang & Zhang Expires September 17, 2020 [Page 5] Internet-Draft EVPN ARP/ND Synch no IRB March 2020 Note that there may be no MAC-VRF here, and this is outside the scope of RFC 7432. * The MPLS Label2 should be set to the local label of the IP-VRF in MPLS or VXLAN EVPN. But it should be set to implicit-null in SRv6 EVPN. Note that the label may be VNI label or MPLS label. Note that in SRv6 EVPN an SRv6 L3 Service TLV MAY also be advertised along with the route following [I-D.dawra-bess-srv6-services]. But SRv6 L2 Service TLV won't be advertiseed along with the route. Because that no MAC-VRF exists in the use case. * The RMAC Extended Community attribute SHOULD be carried in VXLAN EVPN. 2.2. Constructing EAD/IP-VRF Route Note that the MAC/IP Advertisement is used for two reasons. It is used between PE1 and PE2 to synch the ARP entries to each other. It is used between PE1/PE2 and PE3 to achieve the load balance to ES adjacent PEs. The usage/construction of this route is similar to the IP-EAD/EVI route described in [I-D.sajassi-bess-evpn-ip-aliasing] with a few notable exceptions as below. * The MPLS Label should be set to the local label of the IP-VRF in MPLS EVPN or VXLAN EVPN. But it should be set to implicit-null in SRv6 EVPN. Note that there may be no MAC-VRF here, and this is outside the scope of [RFC7432] . Note that in SRv6 EVPN an L3 Service SID MAY also be advertised along with the route following [I-D.dawra-bess-srv6-services]. Such Ethernet Auto-Discovery route is called Ethernet Auto-Discvoery route per IP-VRF which is abbreviated as EAD/IP-VRF in this document. 2.3. Constructing EAD/ES Route The usage/construction of this route remains similar to that described in section 3.1.1. of [I-D.sajassi-bess-evpn-ip-aliasing] with a few notable exceptions as explained as below. There may be no MAC-VRF RTs in the EAD/ES Route. Wang & Zhang Expires September 17, 2020 [Page 6] Internet-Draft EVPN ARP/ND Synch no IRB March 2020 3. Fast Convergence for Routed Traffic The procedures for Fast Convergence do not change from [I-D.sajassi-bess-evpn-ip-aliasing] except for a few notable exceptions as explained as below. The local ARP entries and remote synced ARP entries is installed/ learned on a VRF interface rather than an IRB interface. There is no MAC entry. 4. Determining Reach-ability to Unicast IP Addresses The procedures for local/remote host learning and MAC/IP Advertisement route constructing are described above. The procedures for Route Resolution do not change from [I-D.sajassi-bess-evpn-ip- aliasing]. 5. Forwarding Unicast Packets Because of the nature of the MPLS label or SRv6 SID for IP-VRF instance, when these EAD/IP-VRF routes are referred in IP-VRF routing and forwarding procedures, the inner ethernet headers are absent on the corresponding packets transported following these EAD/IP-VRF routes. Note that in [I-D.sajassi-bess-evpn-ip-aliasing] the inner ethernet header need to be included in the packets which are sent from IP-VRF following IP-EAD/EVI routes, becuase that the MPLS label of such IP- EAD/EVI route is for MAC-VRF, not for IP-VRF. and the inner destination MAC of these packets is following the "Router's MAC" extended community of MAC/IP advertisement routes with non-zero ESI. But in many use cases, the RMAC is not the same as the IRB interface's own MAC and the RMAC is not the same among different PEs. For example, the MAC address of the two IRB interfaces with anycast GW-IP address will be the same, but these two IRB interfaces lies on two different GW node and their "Router's MAC" is typically not the same. In these use cases, it is recommanded to use EAD/IP-VRF route instead, even if there is indeed a MAC-VRF instance. Note that [I-D.sajassi-bess-evpn-ip-aliasing] suggests to carry RMAC in the Ethernet A-D per EVI routes in its version 01. This can be used to solve the problem. Note that in EVPN IRB use cases, the EAD/IP-VRF route is more accordant with the symmetric IRB concept in the sense of data-plane behavior for unicast packets than the IP-EAD/EVI route of [I-D.sajassi-bess-evpn-ip-aliasing]. Wang & Zhang Expires September 17, 2020 [Page 7] Internet-Draft EVPN ARP/ND Synch no IRB March 2020 Note that from the viewpoint of the route receiver It is impossible to distinguish the EAD/IP-VRF route from the IP-EAD/EVI route. So the receiver has to configure how to interprete the remote EAD/EVI route. If it is interpreted as EAD/IP-VRF route, the corresponding transported unicast packets will not be inserted with an ethernet header. But if it is interpreted as IP-EAD/EVI route, they will. Note that we will rely on such configuration only in MPLS/SRv6 EVPN, it is not needed in VXLAN EVPN. 6. EVPN signalled L3VPN EVPN signalled L3VPN can be deployed without EVPN IRB like what MPLS/ BGP VPNs have done for a long time, but it is optional for it to be combined with EVPN IRB. The EVPN siganlled L3VPN without EVPN IRB is not well defined yet, so we take the non-IRB usecase as an example. But the following routes and procedures can be used in EVPN IRB usecase too. Note that in EVPN IRB usecase, the IRB interfaces are VRF-interface too. 6.1. RT-5E Advertisement on Distributed L3 GW Given that PE1/PE2 can receive remote synced ARP entries from each other by RT-2 route following section 2.1. So it is not necessary for PE1/PE2 to advertise per-host IP prefixes by RT-2 routes. It is recommended that PE1/PE2 advertise an RT-5 route per subnet to PE3 instead. The ESI of these RT-5E routes can be set to the ESI of the corresponding VRF interface. If the VRF interface fails, these subnets will achieve more faster convergency on PE3 by the withdraw of the corresponding EAD/IP-VRF route. Note that N1/N2 may be a host or a router, when it is a router, those subnets will be the subnets behind it. When N1 and N2 are hosts, those subnets will be the subnets of N1 and N2 which are from different subnets. 6.2. Centerlized RT-5G Advertisement for Distributed L3 Forwarding When N1/N2/N3 is a router, it is called R1/R2/R3 in the following figure. Note that figure 1 only illustrates the physical ethernet links, but figure 2 illustrates the logical L3 adjacencies betweent PE and CE as the following. Wang & Zhang Expires September 17, 2020 [Page 8] Internet-Draft EVPN ARP/ND Synch no IRB March 2020 PE2 +----+ +---------------+ | | 20.2 | 20.1 +------+ | ------> | R2 |===+------------| | | RT-2E | | | | |IPVRF1| | 20.2 PE3 +----+ | +---------| | | ESI1 +---------------+ Prefix2 | | | 10.1 +------+ | | | | | +---------------+ | +-----------+ | | | ^ | | IPVRF1 | | | | | RT-2E <-------- | | |----R3 | | ESI1 | 10.2 RT-5E | | 3.3.3.3 | | | | | ESI1 Prefix1 | +-----------+ | | | | ESI1 | ^ | | | +---------------+ | | | Prefix1 | | | 20.1 +------+ | +---|-----------+ +----+ +--|---------| | | | | | | | |IPVRF1| | | | R1 |======+---------| | | ------> | | | 10.2 | 10.1 +------+ | RT-2E | +----+ +---------------+ 10.2 | CE-BGP | PE1 ESI1 | Prefix1 | | NH=10.2 | CE-BGP | +------------------------>------------------------+ Figure 2: Centerlized RT-5G Advertisement Note that R1/R2 should establish CE-BGP session with both PE1 and PE2 in case of one of them fails, PE1 and PE2 will advertise RT-5E route to PE3 for their prefixes learned from CE-BGP independently. If R1/ R2 prefers to establish a single CE-BGP session, it can establish the CE-BGP session with PE3 instead. This CE-BGP session can be called the centerlized CE-BGP session. But when we use centerlized CE-BGP session, we should use RT-5G route instead. Note that we just use centerlized CE-BGP session to do route advertisement, but we still expect a distributed Layer 3 forwarding framework. 6.2.1. Centerlized CE-BGP The CE-BGP session between R1 and PE3 is established between 10.2 and 3.3.3.3. The CE-BGP session between R2 and PE3 is established between 20.2 and 3.3.3.3. The IP address 10.2/20.2 is called the uplink interface address of R1/R2 in this document. The IP address 3.3.3.3 is called the centerlized loopback address of IPVRF1 in this document. The IP address 10.1/20.1 is called the downlink interface address of PE1/PE2 in this document. Wang & Zhang Expires September 17, 2020 [Page 9] Internet-Draft EVPN ARP/ND Synch no IRB March 2020 Note that the downlink interface is a Layer 3 link and it needn't attach an BD. R1 advertises a BGP route for a prefix (say "Prefix1") behind it to PE3 via that CE-BGP session. The nexthop for Prefix1 is R1's uplink interface address (say 10.2). The route advertisement of R2 is similar to the above advertisement. Note that the packets from R1/R2 to the centerlized loopback address may be routed following the default route on R1/R2. 6.2.2. RT-2E Advertisement from PE1/PE2 to PE3 When PE1 learns the ARP entry of 10.2, it advertises a RT-2E route to PE3. The ESI value of the RT-2E route is ESI1, which is the ESI of PE1's downlink interface. The RT-2E route is constructed following section 2.1. Note that in [RFC7432], when the ESI is single-active, the MAC forwarding only use the label and MPLS nexthop of the RT-2E route. But in IP forwarding we assume that the ESI is preferred even if the ESI is single-active. This is similar to [I-D.ietf-bess-evpn-prefix-advertisement]. The ESI usage in IP forwarding is out of the [RFC7432]'s scope. The RT-2E route advertisement of PE2 is similar to the above advertisement. 6.2.3. RT-5G Advertisement from PE3 to PE1/PE2 When PE3 receives the prefix1 from the CE-BGP session. The nexthop for Prefix1 is 10.2, and the ESI for 10.2 is ESI1. So PE3 advertises a RT-5G route to PE1/PE2 for Prefix1. The GW-IP value of the RT-5G route for Prefix1 is 10.2. Note that PE3 can load-balance packets for Prefix1 via the EAD/IP-VRF routes from PE1/PE2. Because ESI1 is the ESI for Prefix1's GW-IP. The RT-5 route advertisement and packet forwarding for Prefix2 is similar to the above. Note that the centerlized loopback address is advertised by PE3 via RT-5L route. The nexthop of the RT-5L route is PE3, and the GW-IP value of the RT-5L route is zero. The label of the RT-5L route is IPVRF1's label on PE3. The RMAC of the RT-5L route is PE3's MAC when the encapsulation is VXLAN. Wang & Zhang Expires September 17, 2020 [Page 10] Internet-Draft EVPN ARP/ND Synch no IRB March 2020 6.2.4. RT-2E Advertisement between PE1 and PE2 The RT-2E routes advertisement between PE1 and PE2 is used to sync these ARP entries to each other in order to avoid ARP missing. The ESI Value of these two RT-2E routes is ESI1. Note that the ARP entry for 10.2 will be learned on PE1 only, and 20.2 will be learned on PE2 only. Note that the two downlink interfaces on PE1/PE2 are sub-interfaces of the same physical interface. So they have the same ESI. 6.2.5. Egress ESI Link Protection between PE1 and PE2 The EAD/IP-VRF routes between PE1 and PE2 is used to do egress link protection. The egress link protection follows the second approach of the [RFC8679] section 6. Note that although the ARP entry for 10.2 on PE2 is synced from PE1 via RT-2E route. The ARP entry on PE2 is installed to forward packets directly to the corresponding downlink interface primarily. The bypass tunnel following the EAD/IP-VRF route is only activated when the downlink interface fails. 6.2.6. Comparing with Distributed RT-5G Advertisement When R1/R2 establish CE-BGP sessions with both PE1 and PE2, The RT-5G routes can be used by PE1/PE2. But when R1 only establish just a single CE-BGP session with PE1, there will be some trouble when PE1 fails. Even if PE2/PE3 applies a delayed deletion when PE1 fails, the delay cann't be long enough when PE1 never comes up again. Note that when there is only a single CE-BGP session, the RT-5E advertisement will face the same fact. In fact it is even worse when R1 uses different subnets to connect to PE1 and PE2 as described in [I-D.sajassi-bess-evpn-ip-aliasing]. Because that RT-5E can only sync the prefixes, it can't sync the nexthops, so the ARP entry for the other uplink interface that connects PE2 and R1 will not be resolved. Note that when R1 uses different subnets to connect to PE1 and PE2 , it is not necessary to configure a BD for the two subnets connecting PE and CE as described in [I-D.sajassi-bess-evpn-ip-aliasing]. 6.2.7. Mass-Withdraw by EAD/ES Route We can assume that R1 and R2 are attached to different IP-VRFs(say IPVRF1 and IPVRF2 respectively), and the physical interface of the downlink interfaces on PE1 fails, PE1 will withdraw the EAD/ES route Wang & Zhang Expires September 17, 2020 [Page 11] Internet-Draft EVPN ARP/ND Synch no IRB March 2020 of ESI1, so PE3 will re-route 10.2 for Prefix1 and 20.2 for Prefix2. Then data packets for Prefix1 and Prefix2 will be sent to PE2 instead. 6.3. RT-5L Advertisement When R1/R2 establish CE-BGP sessions with both PE1 and PE2, it is enough for PE1/PE2 to advertise RT-5L routes to PE3. There is no need for RT-5G or RT-5E advertisement on PE1/PE2 in that usecase. Note that when R1/R2 establish CE-BGP sessions with both PE1 and PE2, the downlink interface addresses on PE1 and PE2 may be different IP addresses of the same subnet. Note that when centerlized CE-BGP session is used, the prefixes from R3 and the local loopback addresses on PE3 are advertised to PE1/PE2 using RT-5L too. 7. Load Balancing of Unicast Packets It is similar to [I-D.sajassi-bess-evpn-ip-aliasing] except for a few notable exceptions as explained in section 6.1.3 and the following. Note that when the encapsulation is VXLAN, PE3 will encapsulate the RMAC of the RT-2E route for corresponding GW-IP address. And the RMAC of PE1 should have the same value with the RMAC of PE2. This can be achieved by configuration. When a IP packet is encapsulated with a VNI label according to an EAD/IP-VRF route, the packet SHOULD be encapsulated with a Destination-MAC according to the RMAC of the same EAD/IP-VRF route. Note that PE1/PE2 just do egress link protection following EAD/IP-VRF and EAD/ES route. Even if ESI1 is configured as all-active ESI, PE1/ PE2 will not load-balance between local downlink interface and the bypass tunnel. The downlink interfaces will always have more higher priority than the bypass tunnel. 8. Security Considerations This document does not introduce any new security considerations other than already discussed in [RFC7432] and [RFC8365]. 9. IANA Considerations There is no IANA consideration. Wang & Zhang Expires September 17, 2020 [Page 12] Internet-Draft EVPN ARP/ND Synch no IRB March 2020 10. Normative References [I-D.dawra-bess-srv6-services] Dawra, G., Filsfils, C., Brissette, P., Agrawal, S., Leddy, J., daniel.voyer@bell.ca, d., daniel.bernier@bell.ca, d., Steinberg, D., Raszuk, R., Decraene, B., Matsushima, S., Zhuang, S., and J. Rabadan, "SRv6 BGP based Overlay services", draft-dawra-bess- srv6-services-02 (work in progress), July 2019. [I-D.ietf-bess-evpn-prefix-advertisement] Rabadan, J., Henderickx, W., Drake, J., Lin, W., and A. Sajassi, "IP Prefix Advertisement in EVPN", draft-ietf- bess-evpn-prefix-advertisement-11 (work in progress), May 2018. [I-D.sajassi-bess-evpn-ip-aliasing] Sajassi, A., Badoni, G., Warade, P., Pasupula, S., Drake, J., and J. Rabadan, "L3 Aliasing and Mass Withdrawal Support for EVPN", draft-sajassi-bess-evpn-ip-aliasing-01 (work in progress), March 2020. [RFC7432] Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A., Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based Ethernet VPN", RFC 7432, DOI 10.17487/RFC7432, February 2015, . [RFC8365] Sajassi, A., Ed., Drake, J., Ed., Bitar, N., Shekhar, R., Uttaro, J., and W. Henderickx, "A Network Virtualization Overlay Solution Using Ethernet VPN (EVPN)", RFC 8365, DOI 10.17487/RFC8365, March 2018, . [RFC8679] Shen, Y., Jeganathan, M., Decraene, B., Gredler, H., Michel, C., and H. Chen, "MPLS Egress Protection Framework", RFC 8679, DOI 10.17487/RFC8679, December 2019, . Authors' Addresses Yubao(Bob) Wang ZTE Corporation No. 50 Software Ave, Yuhuatai Distinct Nanjing China Email: yubao.wang2008@hotmail.com Wang & Zhang Expires September 17, 2020 [Page 13] Internet-Draft EVPN ARP/ND Synch no IRB March 2020 Zheng(Sandy) Zhang ZTE Corporation No. 50 Software Ave, Yuhuatai Distinct Nanjing China Email: zzhang_ietf@hotmail.com Wang & Zhang Expires September 17, 2020 [Page 14]