Weighted Multi-Path Procedures for EVPN All-Active Multi-Homing
draft-ietf-bess-evpn-unequal-lb-00
INTERNET-DRAFT N. Malhotra, Ed.
Arrcus
A. Sajassi
Intended Status: Proposed Standard Cisco
J. Rabadan
Nokia
J. Drake
Juniper
A. Lingala
AT&T
S. Thoria
Cisco
Expires: March 23, 2019 September 19, 2018
Weighted Multi-Path Procedures for EVPN All-Active Multi-Homing
draft-ietf-bess-evpn-unequal-lb-00
Abstract
In an EVPN-IRB based network overlay, EVPN LAG enables all-active
multi-homing for a host or CE device connected to two or more PEs via
a LAG bundle, such that bridged and routed traffic from remote PEs
can be equally load balanced (ECMPed) across the multi-homing PEs.
This document defines extensions to EVPN procedures to optimally
handle unequal access bandwidth distribution across a set of multi-
homing PEs in order to:
o provide greater flexibility, with respect to adding or
removing individual PE-CE links within the access LAG
o handle PE-CE LAG member link failures that can result in unequal
PE-CE access bandwidth across a set of multi-homing PEs
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with
the provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as
Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or obsoleted by other
Malhotra et al. Expires March 23, 2019 [Page 1]
INTERNET DRAFT EVPN Unequal Multi-Pathing September 19, 2018
documents at any time. It is inappropriate to use Internet-
Drafts as reference material or to cite them other than as "work
in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/1id-abstracts.html
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html
Copyright and License Notice
Copyright (c) 2017 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
(http://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 . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1 PE CE Link Provisioning . . . . . . . . . . . . . . . . . . 5
1.2 PE CE Link Failures . . . . . . . . . . . . . . . . . . . . 6
1.3 Design Requirement . . . . . . . . . . . . . . . . . . . . . 7
1.4 Terminology . . . . . . . . . . . . . . . . . . . . . . . . 7
2. Solution Overview . . . . . . . . . . . . . . . . . . . . . . . 8
3. Weighted Unicast Traffic Load-balancing . . . . . . . . . . . 8
3.1 LOCAL PE Behavior . . . . . . . . . . . . . . . . . . . . . 8
3.1 Link Bandwidth Extended Community . . . . . . . . . . . . . 8
3.2 REMOTE PE Behavior . . . . . . . . . . . . . . . . . . . . . 9
4. Weighted BUM Traffic Load-Sharing . . . . . . . . . . . . . . 10
4.1 The BW Capability in the DF Election Extended Community . . 10
4.2 BW Capability and Default DF Election algorithm . . . . . . 11
4.3 BW Capability and HRW DF Election algorithm (Type 1 and
4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.3.1 BW Increment . . . . . . . . . . . . . . . . . . . . . . 11
4.3.2 HRW Hash Computations with BW Increment . . . . . . . . 12
4.3.3 Cost-Benefit Tradeoff on Link Failures . . . . . . . . . 13
Show full document text