EVPN All Active Usage Enhancement
draft-eastlake-bess-enhance-evpn-all-active-05
INTERNET-DRAFT D. Eastlake
Intended status: Proposed Standard Futurewei Technologies
Z. Li
S. Zhuang
H. Wang
Huawei Technologies
Expires: January 12, 2021 July 13, 2020
EVPN All Active Usage Enhancement
<draft-eastlake-bess-enhance-evpn-all-active-05.txt>
Abstract
A principal feature of EVPN is the ability to support multihoming
from a customer equipment (CE) to multiple provider edge equipment
(PE) active with all-active links. This draft specifies an
improvement to load balancing such links.
Status of This Memo
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D. Eastlake, et al [Page 1]
INTERNET-DRAFT Enhance All Active EVPN
Table of Contents
1. Introduction............................................3
1.1 Terminology and Acronyms...............................3
2. Improved Load Balancing.................................5
2.1 Problem 1: Traffic Bypassing...........................5
2.2 Problem 2: VID Encapsulation Confusion.................6
3. VLAN-Redirect-Extended Community Attribute..............7
4. Operation...............................................8
4.1 Establishment..........................................8
4.2 Handling Link Failure..................................8
5. IANA Considerations.....................................9
6. Security Considerations.................................9
Normative References......................................10
Informative References....................................10
Acknowledgements..........................................10
Authors' Addresses........................................11
D. Eastlake, et al [Page 2]
INTERNET-DRAFT Enhance All Active EVPN
1. Introduction
A principal feature of EVPN (Ethernet VPN [RFC7432]) is the ability
to support multihoming from a customer equipment (CE) to multiple
provider edge equipments (PEs) with links used in an all-active
redundancy mode. That mode is where a device is multihomed to a group
of two or more PEs and where all PEs in such redundancy group can
forward traffic to/from the multihomed device or network for a given
VLAN [RFC7209]. This draft specifies an improvement in load balancing
such PE to CE all-active multi-homing links.
In the case where a CE is multihomed to multiple PE nodes, using a
Link Aggregation Group (LAG) with All-Active redundancy, it is
possible that only a single PE learns a set of the MAC addresses
associated with traffic transmitted by the CE. This leads to a
situation where remote PE nodes receive MAC/IP Advertisement routes
for these addresses from a single PE, even though multiple PEs are
connected to the multihomed segment.
To address this issue, EVPN introduces the concept of "aliasing",
which is the ability of a PE to signal that it has reachability to an
EVPN instance (EVI) on a given Ethernet segment (ES) even when it has
learned no MAC addresses from that EVI/ES. The Ethernet A-D per EVI
route is used for this purpose. A remote PE that receives a MAC/IP
Advertisement route with a non-reserved ESI SHOULD consider the
advertised MAC address to be reachable via all PEs that have
advertised reachability to that MAC address's EVI/ES via the
combination of an Ethernet A-D per EVI route for that EVI/ES (and
Ethernet tag, if applicable) AND Ethernet A-D per ES routes for that
ES with the "Single-Active" bit in the flags of the ESI Label
extended community set to 0.
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