Date Center Interconnect using TRILL
draft-muks-trill-dci-01
The information below is for an old version of the document.
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|---|---|---|---|
| Authors | Mohammed Umair , Shaji Ravindranathan , Lucy Yong , Donald E. Eastlake 3rd | ||
| Last updated | 2016-02-08 (Latest revision 2015-12-13) | ||
| Replaced by | draft-ietf-trill-dci | ||
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draft-muks-trill-dci-01
INTERNET-DRAFT Mohammed Umair
Intended Status: Informational Kingston Smiler S
Shaji Ravindranathan
IP Infusion
Lucy Yong
Donald Eastlake 3rd
Huawei Technologies
Expires: June 15, 2016 December 13, 2015
Date Center Interconnect using TRILL
<draft-muks-trill-dci-01.txt>
Abstract
This document describes a TRILL based DCI solution. TRILL is
predominantly used inside a data center for providing intra-data
center switching optimally by utilizing multiple links. This draft
provides a way to extend the TRILL network across different data
center via MPLS service provider network using VTSD. VTSD (Virtual
TRILL Service/Switch Domain) is specified in draft [VTSD]. This
document also proposes extensions to existing TRILL protocol to meet
the requirement of data center interconnect.
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79.
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Copyright and License Notice
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Copyright (c) 2015 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
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Table of Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1 Terminology . . . . . . . . . . . . . . . . . . . . . . . . 5
2. Date Center Topology . . . . . . . . . . . . . . . . . . . . . 7
3. Requirement of DCI Protocol . . . . . . . . . . . . . . . . . 7
3.1. Multi-homing with all-active forwarding . . . . . . . . . 7
3.2. Effectively scaling the bandwidth by adding more links . . 8
3.3. Auto-discovery of services . . . . . . . . . . . . . . . . 9
3.4. Delivering Layer 2 and Layer 3 services over the same
interface . . . . . . . . . . . . . . . . . . . . . . . . 9
3.5. BUM traffic optimization . . . . . . . . . . . . . . . . . 9
3.6. Control plane learning of MAC . . . . . . . . . . . . . . 10
3.7. Virtualisation and isolation of different instances . . . 10
3.8. MAC mass-withdrawal . . . . . . . . . . . . . . . . . . . 10
3.9. Significantly larger Name-Space in the Overlay (16M
segments) . . . . . . . . . . . . . . . . . . . . . . . . 10
3.10. Extensive OAM Capabilities . . . . . . . . . . . . . . . 10
3.11. Supporting Ring topology in the Core Network . . . . . . 11
4. TRILL DCI Operations . . . . . . . . . . . . . . . . . . . . . 11
4.1. TRILL data center . . . . . . . . . . . . . . . . . . . . . 12
4.2. Layer2 data center . . . . . . . . . . . . . . . . . . . . 12
4.2.1. TRILL Access load-balancing . . . . . . . . . . . . . 13
4.2.1.1. Appointed Forwarder Mechanism . . . . . . . . . . 13
4.2.1.2. TRILL Active-Active Access . . . . . . . . . . . . 13
4.2.2. TRILL Pseudowire load-balancing . . . . . . . . . . . . 13
5. MPLS encapsulation and Loop free provider PSN/MPLS . . . . . . 14
6. Frame Processing . . . . . . . . . . . . . . . . . . . . . . . 15
6.1. Frame processing between data center T2 switch and TIR. . . 15
6.2. Frame processing between TIR's . . . . . . . . . . . . . . 15
7. Security Considerations . . . . . . . . . . . . . . . . . . . 17
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
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9.1. Normative References . . . . . . . . . . . . . . . . . . . 17
9.2. Informative References . . . . . . . . . . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 21
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1 Introduction
The IETF Transparent Interconnection of Lots of Links (TRILL)
protocol [RFC6325] [RFC7177] [rfc7180bis] provides transparent
forwarding in multi-hop networks with arbitrary topology and link
technologies using a header with a hop count and link-state routing.
TRILL provides optimal pair-wise forwarding without configuration,
safe forwarding even during periods of temporary loops, and support
for multipathing of both unicast and multicast traffic. Intermediate
Systems (ISs) implementing TRILL are called Routing
Bridges(RBridges)or TRILL Switches.
TRILL is predominantly used inside DC for providing intra-data center
switching optimally by utilizing multiple links. Though TRILL runs
within a data center, there is a need to interconnect various data
center sites to provide connectivity across data centers. This draft
proposes a solution to this problem by using VTSD (Virtual TRILL
Switch Domain) as described in the draft [VTSD].
The draft [VTSD] introduces a new terminology called VTSD (Virtual
TRILL Switch Domain) and VPTS (Virtual Private TRILL Service).
The (Virtual Private TRILL Service) VPTS is a L2 TRILL service, that
emulates TRILL service across a Wide Area Network (WAN) over MPLS
PWE3. VPTS is similar to what VPLS does for bridge domain.
The VTSD [Virtual Trill Switch Domain] is similar to VSI (layer 2
bridge) in VPLS model, but this acts as a TRILL RBridge. VTSD is a
superset of VSI and must support all the functionality provided by
the VSI as defined in [RFC4026]. Along with VSI functionality, the
VTSD must be capable of supporting TRILL protocols and form TRILL
adjacency. The VTSD must be capable of performing all the operations
that a standard TRILL Switch can do.
Pseudo Wire Emulation Edge-to-Edge (PWE3) is a mechanism that
emulates the essential attributes of a service such as Ethernet over
a Packet Switched Network (PSN). The required functions of PWs
include encapsulating service-specific PDUs arriving at an ingress
port, and carrying them across a path or tunnel, managing their
timing and order, and any other operations required to emulate the
behavior and characteristics of the service as faithfully as
possible.
The PEs may be connected by an MPLS Label Switched Path (LSP)
infrastructure, which provides the benefits of MPLS technology. The
PEs may also be connected by an IP network, in which case IP/GRE
(Generic Routing Encapsulation) tunneling or other IP tunneling can
be used to provide PSN functionality. The detailed procedures in
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this document are specified only for MPLS LSPs as PSN. However,
these procedures are designed to be extensible to use IP tunnels as
PSN, which is outside the scope of this document.
1.1 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 RFC 2119 [RFC2119].
Acronyms used in this document include the following:
AC - Attachment Circuit [RFC4664]
Access Port - A TRILL switch port configured with
the "end station service enable" bit
on, as described in
Section 4.9.1 of [RFC6325].
All AC's, VTSD ports
connected to CE's, should configured
as TRILL Access port.
AF - Appointed Forwarder [RFC6325],
[RFC6439] and [RFC6439bis].
Data Label - VLAN or FGL
ECMP - Equal Cost Multi Pathing
FGL - Fine-Grained Labeling [RFC7172]
IS-IS - Intermediate System to Intermediate
System [IS-IS]
LAN - Local Area Network
Link - The means by which adjacent TRILL
switches or VTSD is connected.
May be a bridged LAN
MLAG - Multi-Chassis Link Aggregation
MPLS - Multi-Protocol Label Switching
PE - Provider Edge Device
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PSN - Packet Switched Network
PW - Pseudowire [RFC4664]
RBridge - An alternative name for TRILL Switch
TIR - TRILL Intermediate Router
(Devices where Pseudowire starts and
Terminates)
TRILL - Transparent Interconnection of Lots
of Links OR Tunneled Routing in the
Link Layer
TRILL Site - A part of a TRILL campus that
contains at least one RBridge.
TRILL switch - A device implementing the TRILL
protocol. An alternative name
for an RBridge.
Trunk port - A TRILL switch port configured with
the "end station service disable"
bit on, as described in
Section 4.9.1 of [RFC6325].
All pseudowires should
be configured as TRILL Trunk port.
VLAN - Virtual Local Area Network
VPLS - Virtual Private LAN Service
VPTS - Virtual Private TRILL Service
VSI - Virtual Service Instance [RFC4664]
VTSI - Virtual TRILL Service Instance
VTSD - Virtual TRILL Switch Domain OR
Virtual TRILL Service Domain
A Virtual RBridge that segregates
one tenant's TRILL database as well
as traffic from the other.
VTSD-AP - A VTSD TRILL Access port can be a
AC or a logical port connected with
CE's. it can be a combination of
physical port and Data Label.
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OR just Physical port connected to
CE's
2. Date Center Topology
The reference topology that will be used in this draft is a 3 tier
traditional topology. Although other topologies may be utilized
within the data center, most of such L2 based data centers may be
modeled as a 3 tier traditional topology. The reference topology is
illustrated in Figure 1. To keep terminologies simple and uniform, in
this document these layers will be referred to as Tier-1, Tier-2 and
Tier-3 "tiers", and the switches in these layers will be termed as
T1SW, T2SW etc. For simplicity reasons, the entire DC topology will
not be mentioned in the further sections. Only the relevant nodes
will be shown with the above mentioned nomenclature.
+------+ +------+
| | | |
| T1SW1|--| T1SW2| Tier-1
| | | |
+------+ +------+
| | | |
+---------+ | | +----------+
| +-------+--+------+--+-------+ |
| | | | | | | |
+----+ +----+ +----+ +----+
| | | | | | | |
|T2SW|-----|T2SW| |T2SW|-----|T2SW| Tier-2
| | | | | | | |
+----+ +----+ +----+ +----+
| | | |
| | | |
| +-----+ | | +-----+ |
+-|T3SW |-+ +-|T3SW |-+ Tier-3
+-----+ +-----+
| | | | | |
<- Servers -> <- Servers ->
Figure 1: Typical DC network topology
3. Requirement of DCI Protocol
This section describes in detail about the key requirement of a data
center interconnect solution.
3.1. Multi-homing with all-active forwarding
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One of the key requirements of a DCI layer in data center is to
optimally use all the links in the network. There are two types of
links in the DCI layer. The link which provides connectivity to the
data center and the link which provides connectivity to other data
center via backbone network. The DCI layer should use both of these
link types optimally in all-active forwarding manner. Typically the
links towards the data center will have multiple connectivity towards
the peer for providing redundancy in the network. TRILL supports
multiple active parallel links between the TRILL R-Bridges /
traditional L2 bridges. For providing active load-balance for traffic
from layer2 data center TRILL uses the Appointed Forwarder mechanism.
The Appointed forwarder mechanism defined in [rfc6439bis] provides a
way for actively forwarding the traffic by a RBridge, with the intent
that native traffic in each VLAN be handled by at most one RBridge.
By default, the DRB (Designated RBridge) on a link is in-charge of
native traffic for all VLANs on the link. The DRB may, if it wishes,
act as Appointed Forwarder for any VLAN and it may appoint other
RBridges that have ports on the link as Appointed Forwarder for one
or more VLANs. The DRB may appoint other RBridges on the link with
any one of the mechanism described in [rfc6439bis].
A RBridge on a multi-access link forms adjacency [RFC7177] with other
RBridge if the VLAN's configured/enabled between them are common. For
example there are four RBridges attached to multi-access link, say
RB1, RB2, RB3 and RB4. RB1 and RB2 are configured with single VLAN
"VLAN 2", whereas RB3 and RB4 are configured with "VLAN 3". Assume
that there are no Native VLAN's present on any of the RBridges
connected to multi-access link. Since TRILL Hellos are sent with VLAN
Tag enabled on the interface, RB3 and RB4 drops the hellos of RB1 and
RB2 (since they are not configured for VLAN 2). Similarly RB1 and RB2
drops the Hellos of RB3 and RB4. This results in RB1 and RB2 not
forming adjacency with RB3 and RB4. RB1 and RB2 after electing DRB
and forming adjacency between them, will decide about VLAN 2 AF.
Similarly RB3 and RB4 decide about the VLAN 3 AF.
3.2. Effectively scaling the bandwidth by adding more links
As more and more services are deployed over the cloud, there is a
clear requirement for optimally scaling the bandwidth in the network
without disturbing the existing running services. One of the way to
scale the bandwidth is to add a link (either physical/logical link)
across the devices which requires higher bandwidth rate. The same
requirement is applicable in the DCI layer for interfaces towards the
backbone network and towards the data center.
TRILL protocol, by design itself inherently takes care of this by
optimally utilizing multiple links. As PWE3 interface, which provides
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connectivity to different data center is also part of TRILL network,
it is possible to dynamically scale the bandwidth in the backbone
network / DCI interface by adding more PWE3 to the VTSD instance.
3.3. Auto-discovery of services
This is one of the key requirement of data center to provision the
DCI services with minimal configuration effort. Currently TRILL
protocol doesn't have any mechanism to discover the peer VTSD / TIR
nodes. New draft should be proposed to address this gap in TRILL.
3.4. Delivering Layer 2 and Layer 3 services over the same interface
It is desirable to provide a mechanism to advertise both layer2 and
layer3 forwarding information (Route in case of L3 and MAC in case of
L2) to the peer nodes across the data centers. The control plane way
of distributing the forwarding information provides multiple benefits
in terms of scale, performance and security. [ARP/ND-Optimization]
and [IA-APPsub-TLV] provides mechanism to distribute both MAC and IP
information over TRILL network.
3.5. BUM traffic optimization
One of the key design consideration in a DCI network is handling BUM
(Broadcast, Unknown Unicast and Multicast) traffic. If the BUM
packets are handled the way, its been handled in the traditional
layer2 network (by forwarding to all the ports which are part of the
same broadcast domain), this will create overhead in the network.
TRILL takes care of this issue using the distribution tree and
pruning mechanism.
Any unknown unicast, multicast or broadcast frames inside VTSD should
be processed or forwarded through any one of the distribution tree's
path. If any multi-destination frame is received from the wrong
pseudowire at a VTSD, the TRILL protocol running in VTSD should
perform a RPF check as specified in [RFC7180bis] and drops the
packet.
Pruning (VLAN and multicast pruning) mechanism of Distribution Tree
as specified in [RFC6325] and [rfc7180bis] can also be used for
forwarding of multi-destination data frames on the branches that are
not pruned.
Also the ARP/ND-proxy and control plane MAC address learning
mechanism mentioned in section 3.4 and 3.6 will help the
VTSD/RBridges in the network to learn the unicast MAC address from
ARP/ND packets which reduces the unknown unicast flow.
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3.6. Control plane learning of MAC
Learning MAC address in data plane brings scaling limitation of the
devices in the DCI layer. Hence the protocol which provides DCI is
desirable to provide control plane learning to overcome the data
plane learning limitation. Mac address learning through ESADI (End
Station Address Distribution Information Protocol) is described in
the [RFC7357] and requires no changes in the protocol. However the
following optional extensions can be provided for controlling the MAC
learning mechanism.
a) Way to disable remote MAC Addresses learning through data plane
and b) Control over the number of MAC Addresses to be advertised to
the remote VTSD's.
The mechanism to provide these optional extensions is out side the
scope of this document.
3.7. Virtualisation and isolation of different instances
VTSD provides a way to isolate the TRILL databases and the forwarding
information across different TRILL sites. As VPTS is similar to
VPLS, the mac address and the nickname learnt on a particular VPTS is
isolated from other VPTS instance in the system.
3.8. MAC mass-withdrawal
It is desirable in the data center to have a mechanism to flush set
of MAC address in the network, in the event of node failures in the
network. This Mass MAC-Address withdrawal may also applicable when
there is any movement in the End-stations. Mass Mac-Address
withdrawal is specified in draft [Address-Flush] and require no
changes in the protocol.
3.9. Significantly larger Name-Space in the Overlay (16M segments)
Layer2 DCI technologies can be used to provide overlay connectivity
between TORs over an IP underlay. When a DCI protocol is used as an
overlay, there is a clear requirement to have larger namespace to
provide services to different customers. TRILL FGL [RFC7172] provides
2^24 data labels to isolate different TRILL services.
3.10. Extensive OAM Capabilities
It is desirable to provide extensive OAM support in the data center
network for fault indication, fault localization, performance
information and diagnostic functions. TRILL already provides
extensive support for OAM capabilities as specified in [RFC7174] and
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[RFC7175]. These mechanisms can be used for fault indication,
localization and performance information.
3.11. Supporting Ring topology in the Core Network
In most cases, the backbone network which provides connectivity to
the data centers are deployed as a ring topology to provide fault
tolerance. It is highly desirable to provide a similar kind of
service by the DCI protocol. Most of the existing DCI technologies
like VPLS doesn't provide this support due to split horizon rule
running inside the backbone network.
In case of VTSD, as TRILL takes care of forming loop-free topology,
there is no need to run split horizon in the backbone network. This
paves the way for traffic to move from one PW to another PW and
eases the formation of service over ring topology in the core,
without having any mesh or hub-spoke connections.
4. TRILL DCI Operations
The below diagram represents high level overview of TRILL DCI. In the
below diagram there are two data centers as DataCenter1 and
DataCenter2. DataCenter1 has two core routers (which is also part of
the backbone network) as TIR1 and TIR2. Similarly DataCenter2 has
only one core router as TIR3. These TIR devices are connected via
backbone network using PSN Tunnels. Pseudowires are configured across
these devices.
Operations of VTSD is described in draft [VTSD]. There are multiple
attachment circuit interfaces which are configured from T2SW to TIR1
and TIR2. The T2SW can be part of Layer2 network (Layer2 data center)
or TRILL network (TRILL data center).
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|<-------------- Emulated Service ---------------->|
| |
| |<------- Pseudo Wire ------>| |
| | | |
| | |<-- PSN Tunnels-->| | |
| V V V V |
V AC +----+ +----+ AC V
+-----+ | |TIR1|==================| | | +-----+
| |----------|....|..PW1..(active)...|....| | | |
| |_ _|T1SW|==================| | | | |
| | \ / +----+ |TIR3| | | |
| | \ / | | | |T2SW |
| | \ / | |----------| |
|T2SW | \/ | | | |
| | /\ |T1SW| | |
| | / \ +----+ | | +-----+
| |_ / \_ |TIR2|==================| |
| |----------|....|..PW2..(active)...|....|
+-----+ | |T1SW|==================| |
AC +----+ +----+
<-----DataCenter1------> <-----DataCenter2------>
Figure 1: Data Center DCI
4.1. TRILL data center
In this case, the VTSD or TIR will form TRILL adjacency with other
VTSDs present in its peer VPTS neighbor, and also the RBridges
present in the TRILL sites (here it is T2SW). As the entire network
runs TRILL protocol (from data center1 to data center2), TRILL will
take care of efficiently using the multiple attachment circuit
interfaces and PWE3 interfaces. Load balancing of frames between
Tier-2 switch and VTSD will be taken care by TRILL protocol running
inside the RBridges (Tier-2 Switch) and VTSD (Tier-1 Switch) as
described in draft [VTSD].
4.2. Layer2 data center
In case of layer2 data center, as Tier-2 switches are Layer-2
Ethernet switches, an Attachment Circuit should work as a normal
TRILL Access port. As the data center is not running TRILL protocol,
the mechanism to provide active load balancing for Attachment Circuit
differs from the TRILL data center. The subsequent sections describe
in detail about the operation of TRILL access load-balancing in
layer2 data center.
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4.2.1. TRILL Access load-balancing
This section describes the mechanism to provide active load balancing
across Tier1 and Tier2 switch. There are two ways to provide the load
balancing.
a) Using Appointed Forwarder mechanism [rfc6339bis] (load-balancing
based on VLAN) b) Using TRILL Active-Active Access mechanism
[RFC7379] (Similar to MLAG solution)
4.2.1.1. Appointed Forwarder Mechanism
The Appointed forwarder mechanism defined in [rfc6439bis] provides a
way for actively forwarding the traffic by a RBridge, with the intent
that native traffic in each VLAN be handled by at most one RBridge.
By default, the DRB (Designated RBridge) on a link is in-charge of
native traffic for all VLANs on the link. The DRB may, if it wishes,
act as Appointed Forwarder for any VLAN and it may appoint other
RBridges that have ports on the link as Appointed Forwarder for one
or more VLANs. The DRB may appoint other RBridges on the link with
any one of the mechanism described in [rfc6439bis]. Based on the type
of attachment circuit (port-based or VLAN based), the DRB chooses the
appointed forwarder RBridges/VTSDs, which can distribute the traffic
based on the VLANs.
4.2.1.1.1. Port-based AC operations.
In this case, the VTSDs in TIR1 and TIR2 will form TRILL adjacency
via AC ports. If the attachment circuit port can carry N number of
end-station service VLANs, then TIR1 and TIR2's VTSDs can equally
distribute them using AF Mechanism of TRILL.
4.2.1.1.2. VLAN-based AC operations.
Likewise in Port-based AC, in this case also the VTSDs in TIR1 and
TIR2 will form TRILL adjacency via AC ports. Since only one VLAN end-
station service is enabled per VTSD, only one TIR's VTSD can become
AF for that VLAN. Hence native traffic can be processed by any one of
the AC.
4.2.1.2. TRILL Active-Active Access
TRILL Active-Active Access is specified in [RFC7379], [Pseudo-
Nickname], [Centralized-replication] and [AA-Multi-Attach]. Mechanism
specified in these drafts can be utilized effectively for having
TRILL Active-Active Access.
4.2.2. TRILL Pseudowire load-balancing
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TRILL supports multiple parallel adjacencies between neighbor
RBridges. Appendix C of [RFC6325] and section 3.5 of [RFC7177]
describes this in detail. Multipathing across such parallel
connections can be done for unicast TRILL Data traffic on a per-flow
basis, but is restricted for multi-destination traffic. VTSD should
also support this functionality.
TRILL DCI Pseudowires which belong to same VTSD instance in a TIR and
connected to same remote TIR are referred to as parallel pseudowires.
These parallel pseudowires corresponds to a single link inside VTSD.
Here all pseudowires should be capable of carrying traffic.
|<-------------- Emulated Service ------------------>|
| |
| |<------- Pseudo Wire ------>| |
| | | |
| | |<-- PSN Tunnels-->| | |
| V V V V |
V AC +-----+ PW1 +-----+ AC V
+------+ | |VTSD1|==================|VTSD1| | +-------+
| |----------| | | |-------| |
|T2SW | | T1SW|==================| T1SW| | T2SW |
| | +-----+ PW2 +-----+ | |
+------+ +-------+
<-----DataCenter1------> <-----DataCenter2------>
Figure 2: Parallel pseudowires with TRILL DCI
In above Figure 2, PW1 and PW2 are parallel pseudowires, as these
pseudowires belongs to same VTSD and provides a connectivity across
same TIRs.
This mechanism provides a way for actively increasing and optimally
utilizing the bandwidth in the backbone network without affecting the
existing traffic.
5. MPLS encapsulation and Loop free provider PSN/MPLS
TRILL with MPLS encapsulation over pseudowire is specified in
[RFC7173], and requires no changes in the frame format.
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TRILL DCI doesn't require to employ Split Horizon mechanism in the
backbone PSN network, as TRILL takes care of Loop free topology using
Distribution Trees. Any multi-destination frame will traverse a
distribution tree path. All distribution trees are calculated based
on TRILL base protocol standard [RFC6325] as updated by [RFC7180bis].
6. Frame Processing
This section specifies frame processing from data center T2 switch
and TIR's
6.1. Frame processing between data center T2 switch and TIR.
In a multi-homed topology, where in a data center switch (T2SW) is
connected to two TIRs, AF mechanism described in section 4.2.1.1 will
be used to decide which TIR/VTSD will carry the traffic for a
particular VLAN. This is applicable to the case wherein the data
center switch is connected to a PE/TIR device via multiple layer 2
interfaces to increase the bandwidth.
As a frame gets ingressed into a TIR (or any one of the TIR, when the
T2SW switches are connected to multiple TIR's) after having AF check,
the TIR encapsulates the frame with TRILL and MPLS headers and
forwards the frame on a pseudowire. If parallel pseudowires are
present, the TRILL protocol running in VTSD will select any one of
the pseudowire and forward the TRILL Data packet. Multi-destination
packets will be forwarded on Distribution tree's path [rfc7180bis]
Even if any of the paths or links fails between T2SW switch and TIR's
or between TIR's, frames can be always be forwarded to any of
available UP links or paths through other links/pseudowires. This is
one of the key advantage provided by TRILL DCI mechanism.
If multiple equal paths are available, TRILL will distribute traffic
among all the paths.
Also VTSD doesn't depend on the routing or signaling protocol that is
running between TIRs, provided there is a PSN tunnel available with
proper encapsulation mechanism.
Any multi-destination frames, when ingressed to TIR's will traverse
one of the distribution trees, with strong RPF Checks. Hop count
field in TRILL Header will avoid loops or duplication of traffic.
6.2. Frame processing between TIR's
When a frame arrives from T2SW switch to a VTSD inside TIR, the TRILL
protocol will forward the frames to the proper pseudowire. When
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multiple paths/pseudowires are available between the TIR's then, the
shortest path calculated by TRILL protocol will be used. If multiple
paths are of equal cost, then TRILL protocol will do ECMP load
spreading. If any multi-destination frame gets received by the VTSD
through a pseudowire, TRILL will do an RPF check.
When a frame arrives from peer TIR/VTSD through pseudowire, MPLS
header will be de-capsulated, further action will be taken depending
on the egress nickname field of TRILL header. If egress nickname is
the nickname of this VTSD, MAC address table and AF lookup will be
performed and the frame will be forwarded by decapsulating the TRILL
header. If egress nickname belongs to some other VTSD, frame will be
forwarded on a pseudowire connected to that VTSD by encapsulating
with an MPLS header.
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7. Security Considerations
TBD
8. IANA Considerations
This document requires no IANA actions.
RFC Editor: Please delete this section before publication
9. References
9.1. Normative References
[IS-IS] "Intermediate system to Intermediate system routeing
information exchange protocol for use in conjunction with
the Protocol for providing the Connectionless-mode Network
Service (ISO 8473)", ISO/IEC 10589:2002, 2002".
[RFC6325] Perlman, R., Eastlake 3rd, D., Dutt, D., Gai, S., and A.
Ghanwani, "Routing Bridges (RBridges): Base Protocol
Specification", RFC 6325, DOI 10.17487/RFC6325, July 2011,
<http://www.rfc-editor.org/info/rfc6325>.
[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,
<http://www.rfc-editor.org/info/rfc4762>.
[RFC4124] Le Faucheur, F., Ed., "Protocol Extensions for Support of
Diffserv-aware MPLS Traffic Engineering", RFC 4124, DOI
10.17487/RFC4124, June 2005, <http://www.rfc-
editor.org/info/rfc4124>.
[RFC3270] Le Faucheur, F., Wu, L., Davie, B., Davari, S., Vaananen,
P., Krishnan, R., Cheval, P., and J. Heinanen, "Multi-
Protocol Label Switching (MPLS) Support of Differentiated
Services", RFC 3270, DOI 10.17487/RFC3270, May 2002,
<http://www.rfc-editor.org/info/rfc3270>.
[RFC6718] Muley, P., Aissaoui, M., and M. Bocci, "Pseudowire
Redundancy", RFC 6718, DOI 10.17487/RFC6718, August 2012,
<http://www.rfc-editor.org/info/rfc6718>.
[RFC7172] Eastlake 3rd, D., Zhang, M., Agarwal, P., Perlman, R., and
D. Dutt, "Transparent Interconnection of Lots of Links
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(TRILL): Fine-Grained Labeling", RFC 7172, DOI
10.17487/RFC7172, May 2014, <http://www.rfc-
editor.org/info/rfc7172>.
[RFC7173] Yong, L., Eastlake 3rd, D., Aldrin, S., and J. Hudson,
"Transparent Interconnection of Lots of Links (TRILL)
Transport Using Pseudowires", RFC 7173, DOI
10.17487/RFC7173, May 2014, <http://www.rfc-
editor.org/info/rfc7173>.
[RFC7174] Salam, S., Senevirathne, T., Aldrin, S., and D. Eastlake
3rd, "Transparent Interconnection of Lots of Links (TRILL)
Operations, Administration, and Maintenance (OAM)
Framework", RFC 7174, DOI 10.17487/RFC7174, May 2014,
<http://www.rfc-editor.org/info/rfc7174>.
[RFC7175] Manral, V., Eastlake 3rd, D., Ward, D., and A. Banerjee,
"Transparent Interconnection of Lots of Links (TRILL):
Bidirectional Forwarding Detection (BFD) Support",
RFC 7175, DOI 10.17487/RFC7175, May 2014, <http://www.rfc-
editor.org/info/rfc7175>.
[RFC7177] Eastlake 3rd, D., Perlman, R., Ghanwani, A., Yang, H., and
V. Manral, "Transparent Interconnection of Lots of Links
(TRILL): Adjacency", RFC 7177, DOI 10.17487/RFC7177, May
2014, <http://www.rfc-editor.org/info/rfc7177>.
[rfc7180bis] Eastlake, D., et al, "TRILL: Clarifications,
Corrections, and Updates", draft-ietf-trill-rfc7180bis,
work in progress.,.
[VTSD] Umair, M., Smiler, K., Eastlake, D., Yong, L.,
"TRILL Transparent Transport over MPLS"
draft-muks-trill-transport-over-mpls, work in
progress.,.
[rfc6439bis] Eastlake, D., et al., "TRILL: Appointed Forwarders",
draft-eastlake-trill-rfc6439bis, work in progress.,.
[IA-APPsub-TLV] Eastlake, D., et al., "TRILL: Interface Addresses
APPsub-TLV", draft-ietf-trill-ia-appsubtlv, work in
progress.,.
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[ARP/ND-Optimization] Li, Y., Eastlake, D., et al., "TRILL: ARP/ND
Optimization", draft-ietf-trill-arp-optimization, work in
progress.,.
[Address-Flush] Hao, W., Eastlake, D., "TRILL: Address Flush
Protocol", draft-hao-trill-address-flush, work in
progress.,.
[Pseudo-Nickname] Zhai, H., et al., "TRILL: Pseudo-Nickname for
Active-Active Access", draft-ietf-trill-pseudonode-
nickname, work in progress.,.
[Centralized-replication] Hao, W., Li, Y., et al., "Centralized
Replication for BUM traffic in active-active edge
connection", draft-ietf-trill-centralized-replication,
work in progress.,.
[AA-Multi-Attach] Zhang, M., et al., "TRILL Active-Active Edge Using
Multiple MAC Attachments", draft-ietf-trill-aa-multi-
attach, work in progress.,.
9.2. Informative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI
10.17487/RFC2119, March 1997, <http://www.rfc-
editor.org/info/rfc2119>.
[RFC4026] Andersson, L. and T. Madsen, "Provider Provisioned Virtual
Private Network (VPN) Terminology", RFC 4026, DOI
10.17487/RFC4026, March 2005, <http://www.rfc-
editor.org/info/rfc4026>.
[RFC4664] Andersson, L., Ed., and E. Rosen, Ed., "Framework for
Layer 2 Virtual Private Networks (L2VPNs)", RFC 4664, DOI
10.17487/RFC4664, September 2006, <http://www.rfc-
editor.org/info/rfc4664>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
DOI 10.17487/RFC4861, September 2007, <http://www.rfc-
editor.org/info/rfc4861>.
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[RFC3985] Bryant, S., Ed., and P. Pate, Ed., "Pseudo Wire Emulation
Edge-to-Edge (PWE3) Architecture", RFC 3985, DOI
10.17487/RFC3985, March 2005, <http://www.rfc-
editor.org/info/rfc3985>.
[RFC4023] Worster, T., Rekhter, Y., and E. Rosen, Ed.,
"Encapsulating MPLS in IP or Generic Routing Encapsulation
(GRE)", RFC 4023, DOI 10.17487/RFC4023, March 2005,
<http://www.rfc-editor.org/info/rfc4023>.
[RFC4448] Martini, L., Ed., Rosen, E., El-Aawar, N., and G. Heron,
"Encapsulation Methods for Transport of Ethernet over MPLS
Networks", RFC 4448, DOI 10.17487/RFC4448, April 2006,
<http://www.rfc-editor.org/info/rfc4448>.
[RFC7357] Zhai, H., Hu, F., Perlman, R., Eastlake 3rd, D., and O.
Stokes, "Transparent Interconnection of Lots of Links
(TRILL): End Station Address Distribution Information
(ESADI) Protocol", RFC 7357, DOI 10.17487/RFC7357,
September 2014, <http://www.rfc-editor.org/info/rfc7357>.
[RFC7379] Li, Y., Hao, W., Perlman, R., Hudson, J., and H. Zhai,
"Problem Statement and Goals for Active-Active Connection
at the Transparent Interconnection of Lots of Links
(TRILL) Edge", RFC 7379, DOI 10.17487/RFC7379, October
2014, <http://www.rfc-editor.org/info/rfc7379>.
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Authors' Addresses
Mohammed Umair
IP Infusion
RMZ Centennial
Mahadevapura Post
Bangalore - 560048 India
EMail: mohammed.umair2@gmail.com
Kingston Smiler S
IP Infusion
RMZ Centennial
Mahadevapura Post
Bangalore - 560048 India
EMail: kingstonsmiler@gmail.com
Shaji Ravindranathan
IP Infusion
3965 Freedom Circle, Suite 200
Santa Clara, CA 95054 USA
EMail: srnathan2014@gmail.com
Lucy Yong
Huawei Technologies
5340 Legacy Drive
Plano, TX 75024
USA
Phone: +1-469-227-5837
EMail: lucy.yong@huawei.com
Donald E. Eastlake 3rd
Huawei Technologies
155 Beaver Street
Milford, MA 01757
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USA
Phone: +1-508-333-2270
EMail: d3e3e3@gmail.com
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