Internet Engineering Task Force (IETF) A. Sajassi, Ed.
Request for Comments: 8560 S. Salam
Category: Standards Track Cisco
ISSN: 2070-1721 N. Del Regno
Verizon
J. Rabadan
Nokia
March
April 2019
(PBB-)EVPN
Seamless Integration of Ethernet VPN (EVPN) with (PBB-)VPLS Virtual Private LAN
Service (VPLS) and Their Provider Backbone Bridge (PBB) Equivalents
Abstract
This document specifies mechanisms for backward compatibility of
Ethernet VPN (EVPN) and Provider Backbone Bridge Ethernet VPN (PBB-
EVPN) solutions with Virtual Private LAN Service (VPLS) and Provider
Backbone Bridge VPLS (PBB-VPLS) solutions. It also provides
mechanisms for the seamless integration of these two technologies in
the same MPLS/IP network on a per-VPN-instance basis. Implementation
of this document enables service providers to introduce EVPN/PBB-EVPN
Provider Edges (PEs) in their brownfield deployments of VPLS/PBB-VPLS
networks. This document specifies the control-plane and forwarding
behavior needed for the auto-discovery of the following: 1) a VPN
instance, 2) multicast and unicast operation, and 3) a Media Access
Control (MAC) mobility operation. This enables seamless integration
between EVPN and VPLS PEs as well as between PBB-VPLS and PBB-EVPN
PEs.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8560.
Copyright Notice
Copyright (c) 2019 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
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Specification of Requirements . . . . . . . . . . . . . . 4
1.2. Terms and Abbreviations . . . . . . . . . . . . . . . . . . . . . . 4
1.3. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 6
3. VPLS Integration with EVPN . . . . . . . . . . . . . . . . . 7
3.1. Capability Discovery . . . . . . . . . . . . . . . . . . 7
3.2. Forwarding Setup and Unicast Operation . . . . . . . . . 7
3.3. MAC Mobility . . . . . . . . . . . . . . . . . . . . . . 9
3.4. Multicast Operation . . . . . . . . . . . . . . . . . . . 9 10
3.4.1. Ingress Replication . . . . . . . . . . . . . . . . . 9 10
3.4.2. P2MP Tunnel . . . . . . . . . . . . . . . . . . . . . 10
4. PBB-VPLS Integration with PBB-EVPN . . . . . . . . . . . . . 10
4.1. Capability Discovery . . . . . . . . . . . . . . . . . . 10
4.2. Forwarding Setup and Unicast Operation . . . . . . . . . 10
4.3. MAC Mobility . . . . . . . . . . . . . . . . . . . . . . 12
4.4. Multicast Operation . . . . . . . . . . . . . . . . . . . 12
4.4.1. Ingress Replication . . . . . . . . . . . . . . . . . 12
4.4.2. P2MP Tunnel: Inclusive Tree . . . . . . . . . . . . . 13
5. Security Considerations . . . . . . . . . . . . . . . . . . . 13
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1. Normative References . . . . . . . . . . . . . . . . . . 13
7.2. Informative References . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction
Virtual Private LAN Service (VPLS) and Provider Backbone Bridging
VPLS (PBB-VPLS) are widely deployed Layer 2 VPN (L2VPN) technologies.
Many service providers who are looking at adopting Ethernet VPN
(EVPN) and Provider Backbone Bridging EVPN (PBB-EVPN) want to
preserve their investments in the VPLS and PBB-VPLS networks. Hence,
they require mechanisms by which EVPN and PBB-EVPN technologies can
be introduced into their brownfield VPLS and PBB-VPLS networks
without requiring any upgrades (software or hardware) to these
networks. This document specifies procedures for the seamless
integration of the two technologies in the same MPLS/IP network.
Throughout this document, we use the term "(PBB-)EVPN" to correspond
to both EVPN and PBB-EVPN, and we use the term "(PBB-)VPLS" to
correspond to both VPLS and PBB-VPLS. This document specifies the
control-plane and forwarding behavior needed for 1) auto-discovery of
a VPN instance, 2) multicast and unicast operations, and 3) a MAC
mobility operation. This enables seamless integration between
(PBB-)EVPN Provider Edge (PE) devices and (PBB-)VPLS PEs.
VPLS PE
+---+
|PE1|
+---+
/
EVPN/VPLS PE +---------------+ EVPN/VPLS PE
+---+ | | +---+
|PE4|----| MPLS/IP |---|PE5|
+---+ | Core | +---+
| |
+---------------+
/ \
+---+ +---+
|PE2| |PE3|
+---+ +---+
VPLS PE VPLS PE
Figure 1: Seamless Integration of (PBB-)EVPN and (PBB-)VPLS
Section 2 provides the details of the requirements. Section 3
specifies procedures for the seamless integration of VPLS and EVPN
networks. Section 4 specifies procedures for the seamless
integration of PBB-VPLS and PBB-EVPN networks.
It should be noted that the scenarios for both PBB-VPLS integration
with EVPN and VPLS integration with PBB-EVPN are not covered in this
document because there haven't been any requirements from service
providers for these scenarios; deployments that employ PBB-VPLS
typically require PBB encapsulation for various reasons. Hence, it
is expected that for those deployments, the evolution path would move
from PBB-VPLS towards PBB-EVPN. Furthermore, the evolution path from
VPLS is expected to move towards EVPN.
The seamless integration solution described in this document has the
following attributes:
- When ingress replication is used for multi-destination traffic
delivery, the solution reduces the scope of [MMRP] MMRP (which is a
soft-state protocol) soft-
state protocol defined in Clause 10 of [IEEE.802.1Q]) to only that
of existing VPLS PEs and uses the more robust BGP-based mechanism
for multicast pruning among new EVPN PEs.
- It is completely backward compatible.
- New PEs can leverage the extensive multihoming mechanisms and
provisioning simplifications of (PBB-)EVPN:
(a) Auto-sensing of Multihomed Network (MHN) Networks (MHNs) / Multihomed Device
(MHD)
Devices (MHDs)
(b) Auto-discovery of redundancy group groups
(c) Auto-provisioning of Designated Forwarder election and VLAN
carving
1.1. Specification of Requirements
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
1.2. Terms and Abbreviations
Broadcast domain: In a bridged network,
B-MAC: Backbone MAC, e.g., the broadcast domain
corresponds to a Virtual LAN (VLAN), where a VLAN is typically
represented by a single VLAN ID (VID) but can be represented by
several VIDs where Shared VLAN Learning (SVL) is used, per
[IEEE.802.1ah].
Bridge table: An instantiation of a broadcast domain on a MAC-VRF
(VPN Routing and Forwarding).
RIB: Routing Information Base. An instantiation of a routing table
on a MAC-VRF.
FIB: Forwarding Information Base. An instantiation of a forwarding
table on PE's MAC address
C-MAC: Customer MAC, e.g., a MAC-VRF. host or CE's MAC address
CE: A Customer Edge device, e.g., a host, router, or switch.
MAC-VRF: A Virtual Routing and Forwarding table for Media Access
Control (MAC) addresses on an EVPN PE.
MAC address: Media Access Control address.
C-MAC address: Customer MAC address, e.g., a host or CE's MAC
address.
B-MAC address: Backbone MAC address, e.g., the PE's MAC address. switch
ES: Ethernet Segment. Refers Segment -- refers to the set of Ethernet links
that connects a customer site (device or network) to one
or more PEs.
Ethernet Tag: An Ethernet Tag identifies a particular broadcast
domain, e.g., a VLAN. An EVPN instance consists of one or more
broadcast domains. PEs
FEC: Forwarding Equivalence Class. Class
FIB: Forwarding Information Base -- an instantiation of a
forwarding table on a MAC-VRF
I-SID: Service Instance Identifier
LSP: Label Switched Path. Path
MAC: Media Access Control
MAC-VRF: A Virtual Routing and Forwarding table for Media Access
Control (MAC) addresses on an EVPN PE
MHD: Multihomed Device. Device
MHN: Multihomed Network.
P2MP: Point to Multipoint. A P2MP LSP typically refers to an LSP
for multicast traffic. Network
MP2P: Multipoint to Point. An Point -- an MP2P LSP typically refers to an
LSP for unicast traffic as the result of a downstream-assigned label. downstream-
assigned label
P2MP: Point to Multipoint -- a P2MP LSP typically refers to an
LSP for multicast traffic
PBB: Provider Backbone Bridge. Bridge
(PBB-)EVPN: Both PBB-EVPN and EVPN -- this document uses this
abbreviation when a given description applies to both
technologies
(PBB-)VPLS: Both PBB-VPLS and VPLS -- this document uses this
abbreviation when a given description applies to both
technologies
PE: Provider Edge device. device
PW: Pseudowire
RIB: Routing Information Base -- an instantiation of a routing
table on a MAC-VRF
VSI: Virtual Switch Instance. Instance
VPLS: Virtual Private LAN Service.
Single-Active Service
VPLS A-D: Virtual Private LAN Service with BGP-based auto-discovery
as in [RFC6074]
1.3. Terminology
All-Active redundancy mode: When only a single PE, among all the PEs attached to an Ethernet segment, is
segment are allowed to forward known unicast traffic to/from that
Ethernet segment for a given VLAN, then the Ethernet segment is
defined as operating in Single-Active All-Active redundancy mode.
All-Active
Bridge table: An instantiation of a broadcast domain on a MAC-VRF
(VPN Routing and Forwarding).
Broadcast domain: In a bridged network, the broadcast domain
corresponds to a Virtual LAN (VLAN), where a VLAN is typically
represented by a single VLAN ID (VID) but can be represented by
several VIDs where Shared VLAN Learning (SVL) is used, per
[IEEE.802.1Q].
Ethernet Tag: An Ethernet Tag identifies a particular broadcast
domain, e.g., a VLAN. An EVPN instance consists of one or more
broadcast domains.
Single-Active redundancy mode: When only a single PE, among all the
PEs attached to an Ethernet
segment are segment, is allowed to forward known unicast traffic
to/from that Ethernet segment for a given VLAN, then the Ethernet
segment is defined as operating in All-Active Single-Active redundancy mode.
(PBB-)EVPN: Refers to both PBB-EVPN and EVPN. This document uses
this abbreviation when a given description applies to both
technologies.
(PBB-)VPLS: Refers to both PBB-VPLS and VPLS. This document uses
this abbreviation when a given description applies to both
technologies.
VPLS A-D: Refers to Virtual Private LAN Services with BGP-based
auto-discovery as in [RFC6074].
PW: Pseudowire.
I-SID: Service Instance Identifier.
2. Requirements
The following are the key requirements for backward compatibility
between (PBB-)EVPN and (PBB-)VPLS:
1. The solution must allow for staged migration towards (PBB-)EVPN
on a site-by-site basis per VPN instance, e.g., new EVPN sites to
be provisioned on (PBB-)EVPN Provider Edge devices (PEs).
2. The solution must not require any changes to existing VPLS or
PBB-VPLS PEs, not even a software upgrade.
3. The solution must allow for the coexistence of PE devices running
(PBB-)EVPN and (PBB-)VPLS for the same VPN instance and single-
homed segments.
4. The solution must support single-active redundancy of multihomed
networks and multihomed devices for (PBB-)EVPN PEs.
5. In cases of single-active redundancy, the participant VPN
instances may span across both (PBB-)EVPN PEs and (PBB-)VPLS PEs
as long as the MHD or MHN is connected to (PBB-)EVPN PEs.
6. Support of the All-Active redundancy mode across both (PBB-)EVPN
PEs and (PBB-)VPLS PEs is outside the scope of this document.
All-Active redundancy is not applicable to VPLS and PBB-VPLS.
Therefore, when EVPN (or PBB-EVPN) PEs need to operate seamlessly
with VPLS (or PBB-VPLS) PEs, they MUST use a redundancy mode that
is applicable to VPLS (or PBB-VPLS). This redundancy mode is
Single-Active.
These requirements collectively allow for the seamless insertion of
(PBB-)EVPN technology into brownfield (PBB-)VPLS deployments.
3. VPLS Integration with EVPN
In order to support seamless integration with VPLS PEs, this document
requires that VPLS PEs support VPLS A-D per [RFC6074], and it
requires EVPN PEs to support both BGP EVPN routes per [RFC7432] and
VPLS A-D per [RFC6074]. All the logic for seamless integration shall
reside on the EVPN PEs. If a VPLS instance is set up without the use
of VPLS A-D, it is still possible (but cumbersome) for EVPN PEs to
integrate into that VPLS instance by manually configuring pseudowires
(PWs) to all the VPLS PEs in that instance (i.e., the integration is
no longer seamless).
3.1. Capability Discovery
The EVPN PEs MUST advertise both the BGP VPLS auto-discovery (A-D)
route as well as the BGP EVPN Inclusive Multicast Ethernet Tag (IMET)
route for a given VPN instance. The VPLS PEs only advertise the BGP
VPLS A-D route, per the procedures specified in [RFC4761], [RFC4762]
and [RFC6074]. The operator may decide to use the same Route Target
(RT) to identify a VPN on both EVPN and VPLS networks. In this case,
when a VPLS PE receives the EVPN IMET route, it MUST ignore it on the
basis that it belongs to an unknown Subsequent Address Family
Identifier (SAFI). However, the operator may choose to use two RTs
-- one to identify the VPN on the VPLS network and another for the
EVPN network -- and employ RT-constrained RT Constrain mechanisms [RFC4684] in order
to prevent BGP EVPN routes from reaching the VPLS PEs.
When an EVPN PE receives both a VPLS A-D route as well as an EVPN
IMET route from a given remote PE for the same VPN instance, it MUST
give preference to the EVPN route for the purpose of discovery. This
ensures that, at the end of the route exchanges, all EVPN-capable PEs
discover other EVPN-capable PEs in addition to the VPLS-only PEs for
that VPN instance. Furthermore, all the VPLS-only PEs will discover
the EVPN PEs as if they were standard VPLS PEs. In other words, when
the discovery phase is complete, the EVPN PEs will have discovered
all the PEs in the VPN instance along with their associated
capability (EVPN or VPLS-only), whereas the VPLS PEs will have
discovered all the PEs in the VPN instance as if they were all VPLS-
only PEs.
3.2. Forwarding Setup and Unicast Operation
The procedures for the forwarding state setup and unicast operation
on the VPLS PE are per [RFC8077], [RFC4761], and [RFC4762].
The procedures for forwarding state setup and unicast operation on
the EVPN PE are as follows:
- The EVPN PE MUST establish a PW to each remote PE from which it
has received only a VPLS A-D route for the corresponding VPN
instance and MUST set up the label stack corresponding to the PW
FEC. For seamless integration between EVPN and VPLS PEs, the PW
that is set up between a pair of VPLS and EVPN PEs is between the
VSI of the VPLS PE and the MAC-VRF of the EVPN PE.
- The EVPN PE MUST set up the label stack corresponding to the MP2P
VPN unicast FEC to any remote PE that has advertised an EVPN IMET
route.
- If an EVPN PE receives a VPLS A-D route from a given PE, it sets
up a PW to that PE. If it then receives an EVPN IMET route from
the same PE, the EVPN PE MUST bring that PW operationally down.
- If an EVPN PE receives an EVPN IMET route followed by a VPLS A-D
route from the same PE, then the EVPN PE will set up the PW but
MUST keep it operationally down.
- In case VPLS A-D is not used in some VPLS PEs, the EVPN PEs need
to be provisioned manually with PWs to those remote VPLS PEs for
each VPN instance. In that case, if an EVPN PE receives an EVPN
IMET route from a PE to which a PW exists, the EVPN PE MUST bring
the PW operationally down.
When the EVPN PE receives traffic over the VPLS PWs, it learns the
associated C-MAC addresses in the data plane. The C-MAC addresses
learned over these PWs MUST be injected into the bridge table of the
associated MAC-VRF on that EVPN PE. The learned C-MAC addresses MAY
also be injected into the RIB/FIB tables of the associated MAC-VRF on
that EVPN PE. For seamless integration between EVPN and VPLS PEs,
because these PWs belong to the same split-horizon group (see
[RFC4761] and [RFC4762]) as the MP2P EVPN service tunnels, the C-MAC
addresses learned and associated with the PWs MUST NOT be advertised
in the control plane to any remote EVPN PEs. This is because every
EVPN PE can send and receive traffic directly to/from every VPLS PE
belonging to the same VPN instance; thus, every EVPN PE can learn the
C-MAC addresses over the corresponding PWs directly.
The C-MAC addresses learned over local Attachment Circuits (ACs) by
an EVPN PE are learned in the data plane. For EVPN PEs, these C-MAC
addresses MUST be injected into the corresponding MAC-VRF and
advertised in the control plane using BGP EVPN routes. Furthermore,
the C-MAC addresses learned in the control plane via the BGP EVPN
routes sent by remote EVPN PEs are injected into the corresponding
MAC-VRF table.
In case of a link failure in a single-active Ethernet segment, the
EVPN PEs MUST perform both of the following tasks:
1. send a BGP mass withdraw to the EVPN peers
2. follow existing VPLS MAC Flush procedures with the VPLS peers
3.3. MAC Mobility
In EVPN, host addresses (C-MAC addresses) can move around among EVPN
PEs or even between EVPN and VPLS PEs.
When a C-MAC address moves from an EVPN PE to a VPLS PE, as soon as
Broadcast, Unknown Unicast, and Multicast (BUM) traffic is initiated
from that MAC address, it is flooded to all other PEs (both VPLS and
EVPN PEs), and the receiving PEs update their MAC tables (VSI or MAC-
VRF). The EVPN PEs do not advertise the C-MAC addresses learned over
the PW to each other because every EVPN PE learns them directly over
its associated PW to that VPLS PE. If only known unicast traffic is
initiated from the moved C-MAC address toward a known C-MAC, the
result can be the black-holing of traffic destined to the C-MAC that
has moved until there is BUM traffic that has been originated with
the moved C-MAC address as the source MAC address (e.g., as a result
of the MAC age-out timer expiring). Such black-holing happens for
traffic destined to the moved C-MAC from both EVPN and VPLS PEs and
is typical for VPLS PEs.
When a C-MAC address moves from a VPLS PE to an EVPN PE, then as soon
as any traffic is initiated from that C-MAC address, the C-MAC is
learned and advertised in the BGP to other EVPN PEs, and the MAC
mobility procedure is performed among EVPN PEs. For BUM traffic,
both EVPN and VPLS PEs learn the new location of the moved C-MAC
address; however, if there is only known unicast traffic, then only
EVPN PEs learn the new location of the C-MAC that has moved and not
VPLS PEs. This can result in the black-holing of traffic sent from
VPLS PEs destined to the C-MAC that has moved until there is BUM
traffic originated with the moved C-MAC address as the source MAC
address (e.g., as a result of the MAC age-out timer expiring). Such
black-holing happens for traffic destined to the moved C-MAC for only
VPLS PEs but not for EVPN PEs and is typical for VPLS PEs.
3.4. Multicast Operation
3.4.1. Ingress Replication
The procedures for multicast operation on the VPLS PE using ingress
replication are per [RFC4761], [RFC4762], and [RFC7080].
The procedures for multicast operation on the EVPN PE for ingress
replication are as follows:
- The EVPN PE builds a replication sub-list to all the remote EVPN
PEs per EVPN instance as the result of the exchange of the EVPN
IMET routes per [RFC7432]. This will be referred to as sub-list
A. It comprises MP2P service tunnels (for ingress replication)
used for delivering EVPN BUM traffic [RFC7432].
- The EVPN PE builds a replication sub-list per VPLS instance to all
the remote VPLS PEs. This will be referred to as sub-list B. It
comprises PWs from the EVPN PE in question to all the remote VPLS
PEs in the same VPLS instance.
The replication list, maintained per VPN instance, on a given EVPN PE
will be the union of sub-list A and sub-list B. The EVPN PE MUST
enable split horizon over all the entries in the replication list
across both PWs and MP2P service tunnels.
3.4.2. P2MP Tunnel
The procedures for multicast operation on the EVPN PEs using P2MP
tunnels are outside of the scope of this document.
4. PBB-VPLS Integration with PBB-EVPN
In order to support seamless integration between PBB-VPLS and PBB-
EVPN PEs, this document requires that PBB-VPLS PEs support VPLS A-D
per [RFC6074] and PBB-EVPN PEs support both BGP EVPN routes per
[RFC7432] and VPLS A-D per [RFC6074]. All the logic for this
seamless integration shall reside on the PBB-EVPN PEs.
4.1. Capability Discovery
The procedures for capability discovery are per Section 3.1.
4.2. Forwarding Setup and Unicast Operation
The procedures for forwarding state setup and unicast operation on
the PBB-VPLS PE are per [RFC8077] and [RFC7080].
The procedures for forwarding state setup and unicast operation on
the PBB-EVPN PE are as follows:
- The PBB-EVPN PE MUST establish a PW to each remote PBB-VPLS PE
from which it has received only a VPLS A-D route for the
corresponding VPN instance and MUST set up the label stack
corresponding to the PW FEC. For seamless integration between
PBB-EVPN and PBB-VPLS PEs, the PW that is set up between a pair of
PBB-VPLS and PBB-EVPN PEs is between the B-components of PBB-EVPN
PE and PBB-VPLS PE per Section 4 of [RFC7041].
- The PBB-EVPN PE MUST set up the label stack corresponding to the
MP2P VPN unicast FEC to any remote PBB-EVPN PE that has advertised
an EVPN IMET route.
- If a PBB-EVPN PE receives a VPLS A-D route from a given PE, it
sets up a PW to that PE. If it then receives an EVPN IMET route
from the same PE, the PBB-EVPN PE MUST bring that PW operationally
down.
- If a PBB-EVPN PE receives an EVPN IMET route followed by a VPLS
A-D route from the same PE, then the PBB-EVPN PE will set up the
PW but MUST keep it operationally down.
- In case VPLS A-D is not used in some PBB-VPLS PEs, the PBB-EVPN
PEs need to be provisioned manually with PWs to those remote PBB-
VPLS PEs for each VPN instance. In that case, if a PBB-EVPN PE
receives an EVPN IMET route from a PE to which a PW exists, the
PBB-EVPN PE MUST bring the PW operationally down.
- When the PBB-EVPN PE receives traffic over the PBB-VPLS PWs, it
learns the associated B-MAC addresses in the data plane. The
B-MAC addresses learned over these PWs MUST be injected into the
bridge table of the associated MAC-VRF on that PBB-EVPN PE. The
learned B-MAC addresses MAY also be injected into the RIB/FIB
tables of the associated MAC-VRF on that BPP-EVPN PE. For
seamless integration between PBB-EVPN and PBB-VPLS PEs, since
these PWs belong to the same split-horizon group as the MP2P EVPN
service tunnels, the B-MAC addresses learned and associated with
the PWs MUST NOT be advertised in the control plane to any remote
PBB-EVPN PEs. This is because every PBB-EVPN PE can send and
receive traffic directly to/from every PBB-VPLS PE belonging to
the same VPN instance.
- The C-MAC addresses learned over local Attachment Circuits (ACs)
by a PBB-EVPN PE are learned in the data plane. For PBB-EVPN PEs,
these C-MAC addresses are learned in the I-component of PBB-EVPN
PEs and are not advertised in the control plane, per [RFC7623].
- The B-MAC addresses learned in the control plane via the BGP EVPN
routes sent by remote PBB-EVPN PEs are injected into the
corresponding MAC-VRF table.
In case of a link failure in a single-active Ethernet segment, the
PBB-EVPN PEs MUST perform both of the following tasks:
1. send a BGP B-MAC withdraw message to the PBB-EVPN peers *or* MAC
advertisement with the MAC Mobility extended community
2. follow existing VPLS MAC Flush procedures with the PBB-VPLS peers
4.3. MAC Mobility
In PBB-EVPN, a given B-MAC address can be learned either over the BGP
control plane from a remote PBB-EVPN PE or in the data plane over a
PW from a remote PBB-VPLS PE. There is no mobility associated with
B-MAC addresses in this context. Hence, when the same B-MAC address
shows up behind both a remote PBB-VPLS PE as well as a PBB-EVPN PE,
the local PE can deduce that it is an anomaly and SHOULD notify the
operator.
4.4. Multicast Operation
4.4.1. Ingress Replication
The procedures for multicast operation on the PBB-VPLS PE using
ingress replication are per [RFC7041] and [RFC7080].
The procedures for multicast operation on the PBB-EVPN PE for ingress
replication are as follows:
- The PBB-EVPN PE builds a replication sub-list per I-SID to all the
remote PBB-EVPN PEs in a given VPN instance as a result of the
exchange of the EVPN IMET routes, as described in [RFC7623]. This
will be referred to as sub-list A. It comprises MP2P service
tunnels used for delivering PBB-EVPN BUM traffic.
- The PBB-EVPN PE builds a replication sub-list per VPN instance to
all the remote PBB-VPLS PEs. This will be referred to as sub-list
B. It comprises PWs from the PBB-EVPN PE in question to all the
remote PBB-VPLS PEs in the same VPN instance.
- The PBB-EVPN PE may further prune sub-list B on a per-I-SID basis
by running [MMRP] MMRP (see Clause 10 of [IEEE.802.1Q]) over the PBB-VPLS
network. This will be referred to as sub-list C. This list
comprises a pruned set of the PWs in sub-list B.
The replication list maintained per I-SID on a given PBB-EVPN PE will
be the union of sub-list A and sub-list B if [MMRP] MMRP is not used and the
union of sub-list A and sub-list C if [MMRP] MMRP is used. Note that the PE
MUST enable split horizon over all the entries in the replication
list, across both pseudowires and MP2P service tunnels.
4.4.2. P2MP Tunnel: Inclusive Tree
The procedures for multicast operation on the PBB-EVPN PEs using P2MP
tunnels are outside of the scope of this document.
5. Security Considerations
All the security considerations in [RFC4761], [RFC4762], [RFC7080],
[RFC7432], and [RFC7623] apply directly to this document because it
leverages the control-plane and data-plane procedures described in
those RFCs.
This document does not introduce any new security considerations
beyond those of the above RFCs because the advertisements and
processing of MAC addresses in BGP follow [RFC7432], and the
processing of MAC addresses learned over PWs follows [RFC4761],
[RFC4762], and [RFC7080].
6. IANA Considerations
This document has no IANA actions.
7. References
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8077] Martini, L., Ed. and G. Heron, Ed., "Pseudowire Setup and
Maintenance Using the Label Distribution Protocol (LDP)",
STD 84, RFC 8077, DOI 10.17487/RFC8077, February 2017,
<https://www.rfc-editor.org/info/rfc8077>.
[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, <https://www.rfc-editor.org/info/rfc7432>.
[RFC7623] Sajassi, A., Ed., Salam,
7. References
7.1. Normative References
[RFC2119] Bradner, S., Bitar, N., Isaac, A., and W.
Henderickx, "Provider Backbone Bridging Combined with
Ethernet VPN (PBB-EVPN)", "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 7623, 2119,
DOI 10.17487/RFC7623,
September 2015, <https://www.rfc-editor.org/info/rfc7623>. 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC4761] Kompella, K., Ed. and Y. Rekhter, Ed., "Virtual Private
LAN Service (VPLS) Using BGP for Auto-Discovery and
Signaling", RFC 4761, DOI 10.17487/RFC4761, January 2007,
<https://www.rfc-editor.org/info/rfc4761>.
[RFC4762] Lasserre, M., Ed. and V. Kompella, Ed., "Virtual Private
LAN Service (VPLS) Using Label Distribution Protocol (LDP)
Signaling", RFC 4762, DOI 10.17487/RFC4762, January 2007,
<https://www.rfc-editor.org/info/rfc4762>.
[RFC6074] Rosen, E., Davie, B., Radoaca, V., and W. Luo,
"Provisioning, Auto-Discovery, and Signaling in Layer 2
Virtual Private Networks (L2VPNs)", RFC 6074,
DOI 10.17487/RFC6074, January 2011,
<https://www.rfc-editor.org/info/rfc6074>.
[RFC7041] Balus, F., Ed., Sajassi, A., Ed., and N. Bitar, Ed.,
"Extensions to the Virtual Private LAN Service (VPLS)
Provider Edge (PE) Model for Provider Backbone Bridging",
RFC 7041, DOI 10.17487/RFC7041, November 2013,
<https://www.rfc-editor.org/info/rfc7041>.
[RFC6074] Rosen, E., Davie, B., Radoaca, V.,
[RFC7432] Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A.,
Uttaro, J., Drake, J., and W. Luo,
"Provisioning, Auto-Discovery, and Signaling in Layer 2
Virtual Private Networks (L2VPNs)", Henderickx, "BGP MPLS-Based
Ethernet VPN", RFC 6074,
DOI 10.17487/RFC6074, January 2011,
<https://www.rfc-editor.org/info/rfc6074>.
7.2. Informative References
[MMRP] IEEE, "IEEE Standard for Local and metropolitan area
networks -- Bridges and Bridged Networks", IEEE Standard
802.1Q-2014, 7432, DOI 10.1109/IEEESTD.2014.6991462, Clause 10.
[RFC7080] 10.17487/RFC7432, February
2015, <https://www.rfc-editor.org/info/rfc7432>.
[RFC7623] Sajassi, A., Ed., Salam, S., Bitar, N., Isaac, A., and F. Balus, "Virtual
Private LAN Service (VPLS) Interoperability with Provider W.
Henderickx, "Provider Backbone Bridges", Bridging Combined with
Ethernet VPN (PBB-EVPN)", RFC 7080, 7623, DOI 10.17487/RFC7080,
December 2013, <https://www.rfc-editor.org/info/rfc7080>.
[IEEE.802.1ah] 10.17487/RFC7623,
September 2015, <https://www.rfc-editor.org/info/rfc7623>.
[RFC8077] Martini, L., Ed. and G. Heron, Ed., "Pseudowire Setup and
Maintenance Using the Label Distribution Protocol (LDP)",
STD 84, RFC 8077, DOI 10.17487/RFC8077, February 2017,
<https://www.rfc-editor.org/info/rfc8077>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
7.2. Informative References
[IEEE.802.1Q]
IEEE, "IEEE Standard for Local and metropolitan area
networks Metropolitan Area
Network -- Bridges and Bridged Networks", IEEE
Standard 802.1Q, DOI 10.1109/IEEESTD.2011.6009146, Clauses 25 and
26. 10.1109/IEEESTD.2018.8403927, July
2018.
[RFC4684] Marques, P., Bonica, R., Fang, L., Martini, L., Raszuk,
R., Patel, K., and J. Guichard, "Constrained Route
Distribution for Border Gateway Protocol/MultiProtocol
Label Switching (BGP/MPLS) Internet Protocol (IP) Virtual
Private Networks (VPNs)", RFC 4684, DOI 10.17487/RFC4684,
November 2006, <https://www.rfc-editor.org/info/rfc4684>.
[RFC7080] Sajassi, A., Salam, S., Bitar, N., and F. Balus, "Virtual
Private LAN Service (VPLS) Interoperability with Provider
Backbone Bridges", RFC 7080, DOI 10.17487/RFC7080,
December 2013, <https://www.rfc-editor.org/info/rfc7080>.
Authors' Addresses
Ali Sajassi (editor)
Cisco
Email: sajassi@cisco.com
Samer Salam
Cisco
Email: ssalam@cisco.com
Nick Del Regno
Verizon
Email: nick.delregno@verizon.com
Jorge Rabadan
Nokia
Email: jorge.rabadan@nokia.com