BESS WorkGroup N. Malhotra, Ed.
Internet-Draft A. Sajassi
Intended status: Standards Track Cisco Systems
Expires: August 22, 2021 J. Rabadan
Nokia
J. Drake
Juniper
A. Lingala
ATT
S. Thoria
Cisco Systems
February 18, 2021
Weighted Multi-Path Procedures for EVPN All-Active Multi-Homing
draft-ietf-bess-evpn-unequal-lb-08
Abstract
In an EVPN-IRB based network overlay, EVPN all-active multi-homing
enables multi-homing for a CE device connected to two or more PEs via
a LAG, 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
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provisions of BCP 78 and BCP 79.
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material or to cite them other than as "work in progress."
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This Internet-Draft will expire on August 22, 2021.
Copyright Notice
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document authors. All rights reserved.
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Table of Contents
1. Requirements Language and Terminology . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. PE-CE Link Provisioning . . . . . . . . . . . . . . . . . 4
2.2. PE-CE Link Failures . . . . . . . . . . . . . . . . . . . 5
2.3. Design Requirement . . . . . . . . . . . . . . . . . . . 6
3. Solution Overview . . . . . . . . . . . . . . . . . . . . . . 6
4. Weighted Unicast Traffic Load-balancing . . . . . . . . . . . 7
4.1. Local PE Behavior . . . . . . . . . . . . . . . . . . . . 7
4.2. EVPN Link Bandwidth Extended Community . . . . . . . . . 7
4.3. Remote PE Behavior . . . . . . . . . . . . . . . . . . . 8
5. Weighted BUM Traffic Load-Sharing . . . . . . . . . . . . . . 9
5.1. The BW Capability in the DF Election Extended Community . 9
5.2. BW Capability and Default DF Election algorithm . . . . . 10
5.3. BW Capability and HRW DF Election algorithm (Type 1 and
4) . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.3.1. BW Increment . . . . . . . . . . . . . . . . . . . . 11
5.3.2. HRW Hash Computations with BW Increment . . . . . . . 11
5.4. BW Capability and Preference DF Election algorithm . . . 13
6. Cost-Benefit Tradeoff on Link Failures . . . . . . . . . . . 13
7. Real-time Available Bandwidth . . . . . . . . . . . . . . . . 13
8. EVPN-IRB Multi-homing With Non-EVPN routing . . . . . . . . . 14
9. Operational Considerations . . . . . . . . . . . . . . . . . 14
10. Security Considerations . . . . . . . . . . . . . . . . . . . 14
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15
13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 15
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
14.1. Normative References . . . . . . . . . . . . . . . . . . 15
14.2. Informative References . . . . . . . . . . . . . . . . . 16
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Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16
1. Requirements Language and Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
"Local PE" in the context of an ESI refers to a provider edge switch
OR router that physically hosts the ESI.
"Remote PE" in the context of an ESI refers to a provider edge switch
OR router in an EVPN overlay, whose overlay reachability to the ESI
is via the Local PE.
o BW: Band-Width
o LAG: Link Aggregation Group
o ES: Ethernet Segment
o vES: Virtual Ethernet Segment
o EVI: Ethernet virtual Instance, this is a mac-vrf.
o IMET: Inclusive Multicast Route
o DF: Designated Forwarder
o BDF: Backup Designated Forwarder
o DCI: Data Center Interconnect Router
2. Introduction
In an EVPN-IRB based network overlay, with a CE multi-homed via a
EVPN all-active multi-homing, bridged and routed traffic from remote
PEs can be equally load balanced (ECMPed) across the multi-homing
PEs:
o ECMP Load-balancing for bridged unicast traffic is enabled via
o aliasing and mass-withdraw procedures detailed in RFC 7432.
o ECMP Load-balancing for routed unicast traffic is enabled via
existing L3 ECMP mechanisms.
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o Load-sharing of bridged BUM traffic on local ports is enabled via
EVPN DF election procedure detailed in RFC 7432
All of the above load balancing and DF election procedures implicitly
assume equal bandwidth distribution between the CE and the set of
multi-homing PEs. Essentially, with this assumption of equal
"access" bandwidth distribution across all PEs, ALL remote traffic is
equally load balanced across the multi-homing PEs. This assumption
of equal access bandwidth distribution can be restrictive with
respect to adding / removing links in a multi-homed LAG interface and
may also be easily broken on individual link failures. A solution to
handle unequal access bandwidth distribution across a set of multi-
homing EVPN PEs is proposed in this document. Primary motivation
behind this proposal is to enable greater flexibility with respect to
adding / removing member PE-CE links, as needed and to optimally
handle PE-CE link failures.
2.1. PE-CE Link Provisioning
+------------------------+
| Underlay Network Fabric|
+------------------------+
+-----+ +-----+
| PE1 | | PE2 |
+-----+ +-----+
\ /
\ ESI-1 /
\ /
+\---/+
| \ / |
+--+--+
|
CE1
Figure 1
Consider CE1 that is dual-homed to PE1 and PE2 via EVPN all-active
multi-homing with single member links of equal bandwidth to each PE
(aka, equal access bandwidth distribution across PE1 and PE2). If
the provider wants to increase link bandwidth to CE1, it must add a
link to both PE1 and PE2 in order to maintain equal access bandwidth
distribution and inter-work with EVPN ECMP load balancing. In other
words, for a dual-homed CE, total number of CE links must be
provisioned in multiples of 2 (2, 4, 6, and so on). For a triple-
homed CE, number of CE links must be provisioned in multiples of
three (3, 6, 9, and so on). To generalize, for a CE that is multi-
homed to "n" PEs, number of PE-CE physical links provisioned must be
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an integral multiple of "n". This is restrictive in case of dual-
homing and very quickly becomes prohibitive in case of multi-homing.
Instead, a provider may wish to increase PE-CE bandwidth OR number of
links in any link increments. As an example, for CE1 dual-homed to
PE1 and PE2 in all-active mode, provider may wish to add a third link
to only PE1 to increase total bandwidth for this CE by 50%, rather
than being required to increase access bandwidth by 100% by adding a
link to each of the two PEs. While existing EVPN based all-active
load balancing procedures do not necessarily preclude such asymmetric
access bandwidth distribution among the PEs providing redundancy, it
may result in unexpected traffic loss due to congestion in the access
interface towards CE. This traffic loss is due to the fact that PE1
and PE2 will continue to be treated as equal cost paths at remote
PEs, and as a result may attract approximately equal amount of CE1
destined traffic, even when PE2 only has half the bandwidth to CE1 as
PE1. This may lead to congestion and traffic loss on the PE2-CE1
link. If bandwidth distribution to CE1 across PE1 and PE2 is 2:1,
traffic from remote hosts must also be load balanced across PE1 and
PE2 in 2:1 manner.
2.2. PE-CE Link Failures
More importantly, unequal PE-CE bandwidth distribution described
above may occur during regular operation following a link failure,
even when PE-CE links were provisioned to provide equal bandwidth
distribution across multi-homing PEs.
+------------------------+
| Underlay Network Fabric|
+------------------------+
+-----+ +-----+
| PE1 | | PE2 |
+-----+ +-----+
\\ //
\\ ESI-1 //
\\ /X
+\\---//+
| \\ // |
+---+---+
|
CE1
Figure 2
Consider a CE1 that is multi-homed to PE1 and PE2 via a LAG with two
member links to each PE. On a PE2-CE1 physical link failure, LAG
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represented by an Ethernet Segment ESI-1 on PE2 stays up, however,
its bandwidth is cut in half. With existing ECMP procedures, both
PE1 and PE2 may continue to attract equal amount of traffic from
remote PEs, even when PE1 has double the bandwidth to CE1. If
bandwidth distribution to CE1 across PE1 and PE2 is 2:1, traffic from
remote hosts must also be load balanced across PE1 and PE2 in 2:1
manner to avoid unexpected congestion and traffic loss on PE2-CE1
links within the LAG. As an alternative, min-link on LAGs is
sometimes used to bring down the LAG interface on member link
failures. This however results in loss of available bandwidth in the
network, and is not ideal.
2.3. Design Requirement
+-----------------------+
|Underlay Network Fabric|
+-----------------------+
+-----+ +-----+ +-----+ +-----+
| PE1 | | PE2 | ..... | PEx | | PEn |
+-----+ +-----+ +-----+ +-----+
\ \ // //
\ L1 \ L2 // Lx // Ln
\ \ // //
+-\-------\-----------//--------//-+
| \ \ ESI-1 // // |
+----------------------------------+
|
CE
Figure 3
To generalize, if total link bandwidth to a CE is distributed across
"n" multi-homing PEs, with Lx being the total bandwidth to PEx across
all links, traffic from remote PEs to this CE must be load balanced
unequally across [PE1, PE2, ....., PEn] such that, fraction of total
unicast and BUM flows destined for CE that are serviced by PEx is:
Lx / [L1+L2+.....+Ln]
The solution proposed below includes extensions to EVPN procedures to
achieve the above.
3. Solution Overview
In order to achieve weighted load balancing for overlay unicast
traffic, Ethernet A-D per-ES route (EVPN Route Type 1) is leveraged
to signal the Ethernet Segment bandwidth to remote PEs. Using
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Ethernet A-D per-ES route to signal the Ethernet Segment bandwidth
provides a mechanism to be able to react to changes in access
bandwidth in a service and host independent manner. Remote PEs
computing the MAC path-lists based on global and aliasing Ethernet
A-D routes now have the ability to setup weighted load balancing
path-lists based on the ESI access bandwidth received from each PE
that the ESI is multi-homed to.
In order to achieve weighted load balancing of overlay BUM traffic,
EVPN ES route (Route Type 4) is leveraged to signal the ESI bandwidth
to PEs within an ESI's redundancy group to influence per-service DF
election. PEs in an ESI redundancy group now have the ability to do
service carving in proportion to each PE's relative ESI bandwidth.
Procedures to accomplish this are described in greater detail next.
4. Weighted Unicast Traffic Load-balancing
4.1. Local PE Behavior
A PE that is part of an Ethernet Segment's redundancy group would
advertise an additional "link bandwidth" extended community attribute
with Ethernet A-D per-ES route (EVPN Route Type 1), that represents
total bandwidth of PE's physical links in an Ethernet Segment. BGP
link bandwidth extended community defined in [BGP-LINK-BW] is re-used
for this purpose.
4.2. EVPN Link Bandwidth Extended Community
A new EVPN Link Bandwidth extended community is defined to signal
local ES link bandwidth to remote PEs. This extended-community is
defined of type 0x06 (EVPN). IANA is requested to assign a sub-type
value of 0x10 for the EVPN Link bandwidth extended community, of type
0x06 (EVPN). EVPN Link Bandwidth extended community is defined as
transitive.
Link bandwidth extended community described in [BGP-LINK-BW] for
layer 3 VPNs was considered for re-use here. This Link bandwidth
extended community is however defined in [BGP-LINK-BW] as optional
non-transitive. Since it is not possible to change deployed behavior
of extended-community defined in [BGP-LINK-BW], it was decided to
define a new one. In inter-AS scenarios, link-bandwidth needs to be
signaled to eBGP neighbors. When signaled across AS boundary, this
attribute can be used to achieve optimal load-balancing towards
source PEs from a different AS. This is applicable both when next-
hop is changed or unchanged across AS boundaries.
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4.3. Remote PE Behavior
A receiving PE SHOULD use per-ES link bandwidth attribute received
from each PE to compute a relative weight for each remote PE, per-ES,
and then use this relative weight to compute a weighted path-list to
be used for load balancing, as opposed to using an ECMP path-list for
load balancing across the PE paths. PE Weight and resulting weighted
path-list computation at remote PEs is a local matter. An example
computation algorithm is shown below to illustrate the idea:
if,
L(x,y) : link bandwidth advertised by PE-x for ESI-y
W(x,y) : normalized weight assigned to PE-x for ESI-y
H(y) : Highest Common Factor (HCF) of [L(1,y), L(2,y), ....., L(n,y)]
then, the normalized weight assigned to PE-x for ESI-y may be
computed as follows:
W(x,y) = L(x,y) / H(y)
For a MAC+IP route (EVPN Route Type 2) received with ESI-y, receiving
PE may compute MAC and IP forwarding path-list weighted by the above
normalized weights.
As an example, for a CE dual-homed to PE-1, PE-2, PE-3 via 2, 1, and
1 GE physical links respectively, as part of a LAG represented by
ESI-10:
L(1, 10) = 2000 Mbps
L(2, 10) = 1000 Mbps
L(3, 10) = 1000 Mbps
H(10) = 1000
Normalized weights assigned to each PE for ESI-10 are as follows:
W(1, 10) = 2000 / 1000 = 2.
W(2, 10) = 1000 / 1000 = 1.
W(3, 10) = 1000 / 1000 = 1.
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For a remote MAC+IP host route received with ESI-10, forwarding load
balancing path-list may now be computed as: [PE-1, PE-1, PE-2, PE-3]
instead of [PE-1, PE-2, PE-3]. This now results in load balancing of
all traffic destined for ESI-10 across the three multi-homing PEs in
proportion to ESI-10 bandwidth at each PE.
Weighted path-list computation must only be done for an ESI if a link
bandwidth attribute is received from all of the PE's advertising
reachability to that ESI via Ethernet A-D per-ES Route Type 1. In an
unlikely event that link bandwidth attribute is not received from one
or more subset of PEs, forwarding path-list should be computed using
regular ECMP semantics. Note that a default weight cannot be assumed
for a PE that does not advertise its link bandwidth as the weight
attribute t be used in path-list computation is relative.
5. Weighted BUM Traffic Load-Sharing
Optionally, load sharing of per-service DF role, weighted by
individual PE's link-bandwidth share within a multi-homed ES may also
be achieved.
In order to do that, a new DF Election Capability [RFC8584] called
"BW" (Bandwidth Weighted DF Election) is defined. BW MAY be used
along with some DF Election Types, as described in the following
sections.
5.1. The BW Capability in the DF Election Extended Community
[RFC8584] defines a new extended community for PEs within a
redundancy group to signal and agree on uniform DF Election Type and
Capabilities for each ES. This document requests IANA for a bit in
the DF Election extended community Bitmap:
Bit 28: BW (Bandwidth Weighted DF Election)
ES routes advertised with the BW bit set will indicate the desire of
the advertising PE to consider the link-bandwidth in the DF Election
algorithm defined by the value in the "DF Type".
As per [RFC8584], all the PEs in the ES MUST advertise the same
Capabilities and DF Type, otherwise the PEs will fall back to Default
[RFC7432] DF Election procedure.
The BW Capability MAY be advertised with the following DF Types:
o Type 0: Default DF Election algorithm, as in [RFC7432]
o Type 1: HRW algorithm, as in [RFC8584]
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o Type 2: Preference algorithm, as in [EVPN-DF-PREF]
o Type 4: HRW per-multicast flow DF Election, as in [EVPN-PER-MCAST-
FLOW-DF]
The following sections describe how the DF Election procedures are
modified for the above DF Types when the BW Capability is used.
5.2. BW Capability and Default DF Election algorithm
When all the PEs in the Ethernet Segment (ES) agree to use the BW
Capability with DF Type 0, the Default DF Election procedure as
defined in [RFC7432] is modified as follows:
o Each PE advertises a "Link Bandwidth" extended community attribute
along with the ES route to signal the PE-CE link bandwidth (LBW)
for the ES.
o A receiving PE MUST use the ES link bandwidth attribute received
from each PE to compute a relative weight for each remote PE.
o The DF Election procedure MUST now use this weighted list of PEs
to compute the per-VLAN Designated Forwarder, such that the DF
role is distributed in proportion to this normalized weight. As a
result, a single PE may have multiple ordinals in the DF candidate
PE list and 'N' used in (V mode N) operation as defined in
[RFC7432] is modified to be total number of ordinals instead of
being total number of PEs.
Considering the same example as in Section 3, the candidate PE list
for DF election is:
[PE-1, PE-1, PE-2, PE-3].
The DF for a given VLAN-a on ES-10 is now computed as (VLAN-a % 4).
This would result in the DF role being distributed across PE1, PE2,
and PE3 in portion to each PE's normalized weight for ES-10.
5.3. BW Capability and HRW DF Election algorithm (Type 1 and 4)
[RFC8584] introduces Highest Random Weight (HRW) algorithm (DF Type
1) for DF election in order to solve potential DF election skew
depending on Ethernet tag space distribution. [EVPN-PER-MCAST-FLOW-
DF] further extends HRW algorithm for per-multicast flow based hash
computations (DF Type 4). This section describes extensions to HRW
Algorithm for EVPN DF Election specified in [RFC8584] and in [EVPN-
PER-MCAST-FLOW-DF] in order to achieve DF election distribution that
is weighted by link bandwidth.
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5.3.1. BW Increment
A new variable called "bandwidth increment" is computed for each [PE,
ES] advertising the ES link bandwidth attribute as follows:
In the context of an ES,
L(i) = Link bandwidth advertised by PE(i) for this ES
L(min) = lowest link bandwidth advertised across all PEs for this ES
Bandwidth increment, "b(i)" for a given PE(i) advertising a link
bandwidth of L(i) is defined as an integer value computed as:
b(i) = L(i) / L(min)
As an example,
with PE(1) = 10, PE(2) = 10, PE(3) = 20
bandwidth increment for each PE would be computed as:
b(1) = 1, b(2) = 1, b(3) = 2
with PE(1) = 10, PE(2) = 10, PE(3) = 10
bandwidth increment for each PE would be computed as:
b(1) = 1, b(2) = 1, b(3) = 1
Note that the bandwidth increment must always be an integer,
including, in an unlikely scenario of a PE's link bandwidth not being
an exact multiple of L(min). If it computes to a non-integer value
(including as a result of link failure), it MUST be rounded down to
an integer.
5.3.2. HRW Hash Computations with BW Increment
HRW algorithm as described in [RFC8584] and in [EVPN-PER-MCAST-FLOW-
DF] computes a random hash value for each PE(i), where, (0 < i <= N),
PE(i) is the PE at ordinal i, and Address(i) is the IP address of
PE(i).
For 'N' PEs sharing an Ethernet segment, this results in 'N'
candidate hash computations. The PE that has the highest hash value
is selected as the DF.
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We refer to this hash value as "affinity" in this document. Hash or
affinity computation for each PE(i) is extended to be computed one
per bandwidth increment associated with PE(i) instead of a single
affinity computation per PE(i).
PE(i) with b(i) = j, results in j affinity computations:
affinity(i, x), where 1 < x <= j
This essentially results in number of candidate HRW hash computations
for each PE that is directly proportional to that PE's relative
bandwidth within an ES and hence gives PE(i) a probability of being
DF in proportion to it's relative bandwidth within an ES.
As an example, consider an ES that is multi-homed to two PEs, PE1 and
PE2, with equal bandwidth distribution across PE1 and PE2. This
would result in a total of two candidate hash computations:
affinity(PE1, 1)
affinity(PE2, 1)
Now, consider a scenario with PE1's link bandwidth as 2x that of PE2.
This would result in a total of three candidate hash computations to
be used for DF election:
affinity(PE1, 1)
affinity(PE1, 2)
affinity(PE2, 1)
which would give PE1 2/3 probability of getting elected as a DF, in
proportion to its relative bandwidth in the ES.
Depending on the chosen HRW hash function, affinity function MUST be
extended to include bandwidth increment in the computation.
For e.g.,
affinity function specified in [EVPN-PER-MCAST-FLOW-DF] MAY be
extended as follows to incorporate bandwidth increment j:
affinity(S,G,V, ESI, Address(i,j)) =
(1103515245.((1103515245.Address(i).j + 12345) XOR
D(S,G,V,ESI))+12345) (mod 2^31)
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affinity or random function specified in [RFC8584] MAY be extended as
follows to incorporate bandwidth increment j:
affinity(v, Es, Address(i,j)) = (1103515245((1103515245.Address(i).j
+ 12345) XOR D(v,Es))+12345)(mod 2^31)
5.4. BW Capability and Preference DF Election algorithm
This section applies to ES'es where all the PEs in the ES agree use
the BW Capability with DF Type 2. The BW Capability modifies the
Preference DF Election procedure [EVPN-DF-PREF], by adding the LBW
value as a tie-breaker as follows:
Section 4.1, bullet (f) in [EVPN-DF-PREF] now considers the LBW
value:
f) In case of equal Preference in two or more PEs in the ES, the tie-
breakers will be the DP bit, the LBW value and the lowest IP PE in
that order. For instance:
o If vES1 parameters were [Pref=500,DP=0,LBW=1000] in PE1 and
[Pref=500,DP=1, LBW=2000] in PE2, PE2 would be elected due to the
DP bit.
o If vES1 parameters were [Pref=500,DP=0,LBW=1000] in PE1 and
[Pref=500,DP=0, LBW=2000] in PE2, PE2 would be elected due to a
higher LBW, even if PE1's IP address is lower.
o The LBW exchanged value has no impact on the Non-Revertive option
described in [EVPN-DF-PREF].
6. Cost-Benefit Tradeoff on Link Failures
While incorporating link bandwidth into the DF election process
provides optimal BUM traffic distribution across the ES links, it
also implies that DF elections are re-adjusted on link failures or
bandwidth changes. If the operator does not wish to have this level
of churn in their DF election, then they should not advertise the BW
capability. Not advertising BW capability may result in less than
optimal BUM traffic distribution while still retaining the ability to
allow a remote ingress PE to do weighted ECMP for its unicast traffic
to a set of multi-homed PEs.
7. Real-time Available Bandwidth
PE-CE link bandwidth availability may sometimes vary in real-time
disproportionately across PE-CE links within a multi-homed ESI due to
various factors such as flow based hashing combined with fat flows
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and unbalanced hashing. Reacting to real-time available bandwidth is
at this time outside the scope of this document. Procedures
described in this document are strictly based on static link
bandwidth parameter.
8. EVPN-IRB Multi-homing With Non-EVPN routing
EVPN-LAG based multi-homing on an IRB gateway may also be deployed
together with non-EVPN routing, such as global routing or an L3VPN
routing control plane. Key property that differentiates this set of
use cases from EVPN IRB use cases discussed earlier is that EVPN
control plane is used only to enable LAG interface based multi-homing
and NOT as an overlay VPN control plane. EVPN control plane in this
case enables:
o DF election via EVPN RT-4 based procedures described in [RFC7432]
o Local MAC sync across multi-homing PEs via EVPN RT-2
o Local ARP and ND sync across multi-homing PEs via EVPN RT-2
Applicability of weighted ECMP procedures proposed in this document
to these set of use cases is an area of further consideration.
9. Operational Considerations
None
10. Security Considerations
This document raises no new security issues for EVPN.
11. IANA Considerations
[RFC8584] defines a new extended community for PEs within a
redundancy group to signal and agree on uniform DF Election Type and
Capabilities for each ES. This document requests IANA for a bit in
the DF Election extended community Bitmap:
Bit 28: BW (Bandwidth Weighted DF Election)
A new EVPN Link Bandwidth extended community is defined to signal
local ES link bandwidth to remote PEs. This extended-community is
defined of type 0x06 (EVPN). IANA is requested to assign a sub-type
value of 0x10 for the EVPN Link bandwidth extended community, of type
0x06 (EVPN). EVPN Link Bandwidth extended community is defined as
transitive.
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12. Acknowledgements
Authors would like to thank Satya Mohanty for valuable review and
inputs with respect to HRW and weighted HRW algorithm refinements
proposed in this document.
13. Contributors
Satya Ranjan Mohanty
Cisco Systems
US
Email: satyamoh@cisco.com
14. References
14.1. Normative References
[EVPN-DF-PREF]
Rabadan, J., Sathappan, S., Przygienda, T., Lin, W.,
Drake, J., Sajassi, A., Mohanty, S., and , "Preference-
based EVPN DF Election", draft-ietf-bess-evpn-pref-df-06
(work in progress), June 2020.
[EVPN-PER-MCAST-FLOW-DF]
Sajassi, A., mishra, m., Thoria, S., Rabadan, J., and J.
Drake, "Per multicast flow Designated Forwarder Election
for EVPN", draft-ietf-bess-evpn-per-mcast-flow-df-
election-04 (work in progress), August 2020.
[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>.
[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>.
[RFC7814] Xu, X., Jacquenet, C., Raszuk, R., Boyes, T., and B. Fee,
"Virtual Subnet: A BGP/MPLS IP VPN-Based Subnet Extension
Solution", RFC 7814, DOI 10.17487/RFC7814, March 2016,
<https://tools.ietf.org/html/rfc7814>.
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[RFC8584] Rabadan, J., Ed., Mohanty, R., Sajassi, N., Drake, A.,
Nagaraj, K., and S. Sathappan, "Framework for Ethernet VPN
Designated Forwarder Election Extensibility", RFC 8584,
DOI 10.17487/RFC8584, April 2019,
<https://www.rfc-editor.org/info/rfc8584>.
14.2. Informative References
[BGP-LINK-BW]
Mohapatra, P. and R. Fernando, "BGP Link Bandwidth
Extended Community", draft-ietf-idr-link-bandwidth-07
(work in progress), March 2019.
Authors' Addresses
Neeraj Malhotra (editor)
Cisco Systems
170 W. Tasman Drive
San Jose, CA 95134
USA
Email: nmalhotr@cisco.com
Ali Sajassi
Cisco Systems
170 W. Tasman Drive
San Jose, CA 95134
USA
Email: sajassi@cisco.com
Jorge Rabadan
Nokia
777 E. Middlefield Road
Mountain View, CA 94043
USA
Email: jorge.rabadan@nokia.com
John Drake
Juniper
Email: jdrake@juniper.net
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Avinash Lingala
ATT
200 S. Laurel Avenue
Middletown, CA 07748
USA
Email: ar977m@att.com
Samir Thoria
Cisco Systems
170 W. Tasman Drive
San Jose, CA 95134
USA
Email: sthoria@cisco.com
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