Network Working Group L. Yong
Internet Draft Huawei
Category: Informational M. Toy
Comcast
A. Isaac
Bloomberg
V. Manral
Hewlett-Packard
L. Dunbar
Huawei
Expires: November 2013 May 1, January 2014 July 11, 2013
Use Cases for DC Network Virtualization Overlays
draft-ietf-nvo3-use-case-01
draft-ietf-nvo3-use-case-02
Abstract
This document describes the DC NVO3 Network Virtualization (NVO3) use
cases that may be potentially deployed in various data centers and
apply to different applications. An application in a DC may be a combination of some
use cases described here.
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Conventions used in this document
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].
Table of Contents
1. Introduction...................................................3
1.1. Contributors..............................................4
1.2. Terminology...............................................4
2. Basic Virtual Networks in a Data Center........................5 Center........................4
3. Interconnecting DC Virtual Network and External Networks.......6
3.1. DC Virtual Network Access via Internet....................6
3.2. DC VN and Enterprise Sites interconnected via SP WAN......7
4. DC Applications Using NVO3.....................................8
4.1. Supporting Multi Technologies and Applications in a DC....9
4.2. Tenant Network with Multi-Subnets or across multi DCs.....9
4.3. Virtual Data Center (vDC)................................11
5. OAM Considerations............................................13 Considerations............................................12
6. Summary.......................................................13
7. Security Considerations.......................................14
8. IANA Considerations...........................................14
9. Acknowledgements..............................................14
10. References...................................................14
10.1. Normative References....................................14
10.2. Informative References..................................15
Authors' Addresses...............................................15
1. Introduction
Server Virtualization has changed IT industry in terms of efficiency,
cost, and the speed in providing a new applications and/or services.
However the problems in today's data center networks hinder the
support of an elastic cloud service applications and dynamic virtual multi tenant networks [NVO3PRBM].
The goal of DC Network Virtualization Overlays, i.e. NVO3, is to
decouple the communication among tenant systems from DC physical
networks and to allow one physical network infrastructure to provide:
1) traffic isolation among tenant virtual networks over the same
physical network; 2) independent address space in each virtual
network and address isolation from the infrastructure's; 3) Flexible
VM placement and move from one server to another without any of the physical network limitations. VM address
and configuration change. These characteristics will help address
the issues that hinder true
virtualization in the data centers today's cloud applications [NVO3PRBM].
Although NVO3 enables a true network virtualization environment, the
NVO3 solution has to address the communication between a virtual
network and a physical network. This is because 1) many DCs that
need to provide network virtualization are currently running over
physical networks, the migration will be in steps; 2) a lot of DC
applications are served to Internet users which run directly on
physical networks; 3) some applications are CPU bound like Big Data
analytics and may not need the virtualization capability.
This document is to describe general NVO3 use cases that apply to
various data centers. Three types of the use cases described here
are:
o Basic virtual networks in DC. A virtual network connects many
tenant systems within in a Data Center site (or more) and form forms one L2
or L3 communication domain. A Many virtual
network segregates its traffic from others and allows the VMs in
the network moving from one server to another. networks are over same
DC physical network. The case may be used for DC internal
applications that constitute the DC East-
West East-West traffic.
o DC virtual network access from external. A DC provider offers a
secure DC service to an enterprise customer and/or Internet users. In these cases, the
An enterprise customer may use a traditional VPN provided by a
carrier or an IPsec tunnel over Internet connecting to a NVO3 virtual
network within a provider DC. DC site. This is mainly constitutes DC
North-South traffic.
o A DC provider applications or services that may use NVO3. Three scenarios
are described: 1) use NVO3 and other network technologies for to
build a tenant network, network; 2) construct different topologies or zones for several virtual networks as
a tenant network, and may design network; 3) apply NVO3 to a variety of cloud applications
that may require the network service appliance, virtual compute,
storage, and networking. In this case, the NVO3 provides the
networking functions for the applications. DC (vDC) service.
The document uses the architecture reference model defined in
[NVO3FRWK] to describe the use cases.
1.1. Contributors
Vinay Bannai
PayPal
2211 N. First St,
San Jose, CA 95131
Phone: +1-408-967-7784
Email: vbannai@paypal.com
Ram Krishnan
Brocade Communications
San Jose, CA 95134
Phone: +1-408-406-7890
Email: ramk@brocade.com
1.2. Terminology
This document uses the terminologies defined in [NVO3FRWK],
[RFC4364]. Some additional terms used in the document are listed
here.
CPE: Customer Premise Equipment
DMZ: Demilitarized Zone Zone. A computer or small subnetwork that sits
between a trusted internal network, such as a corporate private LAN,
and an un-trusted external network, such as the public Internet.
DNS: Domain Name Service
NAT: Network Address Translation
VIRB: Virtual Integrated Routing/Bridging
Note that a virtual network in this document is a network
virtualization an overlay virtual
network instance.
2. Basic Virtual Networks in a Data Center
A virtual network may exist within a DC. The network enables a
communication among Tenant Systems (TSs) that are in a Closed User
Group (CUG). A TS may be a physical server server/device or a virtual
machine (VM) on a server. The network virtual edge (NVE) may co-exist co-
exist with Tenant Systems, i.e. on an a same end-device, or exist on a
different device, e.g. a top of rack switch (ToR). A virtual network
has a unique virtual network identifier (may be local or global
unique) for an NVE to properly differentiate it from other virtual
networks.
The TSs attached to the same NVE are not necessary in the same CUG,
i.e. in may belong to the same or different
virtual network. The multiple CUGs can be constructed in a way so
that the policies are enforced when the TSs in one CUG communicate
with the TSs in other CUGs. An NVE provides the reachbility for
Tenant Systems in a CUG, and may also have the policies and provide
the reachbility for Tenant Systems in different CUGs (See section
4.2). Furthermore in a DC operators may construct many tenant
networks that have no communication in between at all. In this case,
each tenant network may use its own address space. Note that
one One tenant
network may contain have one or more CUGs. virtual networks.
A Tenant System may also be configured with multiple addresses and
participate in multiple virtual networks, i.e. use different address
in different virtual network. networks. For examples, a TS is may be a NAT GW;
or a TS
is a firewall server for multiple CUGs.
Network Virtualization Overlay in this context means the that a virtual
networks over DC infrastructure
network via a tunnel, is implemented in overlay, i.e. traffic from an NVE to
another is sent via a tunnel
between any pair of NVEs. tunnel.[NVO3FMWK] This architecture decouples
tenant system address schema scheme and configuration from the infrastructure address space,
infrastructure's, which brings a great flexibility for VM placement
and mobility. This also makes the transit nodes in the
infrastructure not aware of the existence of the virtual networks.
One tunnel may carry the traffic belonging to different virtual
networks; a virtual network identifier is used for traffic segregation in a tunnel.
demultiplexing.
A virtual network may be an L2 or L3 domain. An The TSs attached to an
NVE may be a member
of several belong to different virtual networks each of which is that may be in L2 or
L3. A virtual network may carry unicast traffic and/or
broadcast/multicast/unknown traffic from/to tenant systems. An NVE may use p2p tunnels or a p2mp
tunnel There
are several ways to transport broadcast or multicast traffic, or may use other
mechanisms [NVO3MCAST]. BUM traffic.[NVO3MCAST]
It is worth to mention two distinct cases here. The first is that TS
TSs and NVE are co-located on a same end device, which means that
the NVE can be made aware of the TS state at any time via internal
API. The second is that TS TSs and NVE are remotely connected, i.e.
connected via a switched network or point-to-point link. In this
case, a protocol is necessary for NVE to know TS state.
One virtual network may have many NVE members each of which connect many TSs
may TSes that attach to. to many
different NVEs. TS dynamic placement and mobility results in
frequent changes in the TS and NVE bindings. The TS reachbility
update mechanism MUST need be fast enough to not cause any service
interruption. The capability of supporting a lot of many TSs in a tenant virtual
network and a
lot of tenant many more virtual networks in a DC is critical for NVO3
solution.
If a virtual network spans across multiple DC sites, one design is
to allow the corresponding NVO3 instance network seamlessly to span across
those the sites without DC
gateway routers' termination. In this case, the tunnel between a
pair of NVEs may in turn be tunneled over other intermediate tunnels
over the Internet or other WANs, or the intra DC and inter DC
tunnels are stitched together to form an end-to-end virtual network
across DCs. The latter is described in section 3.2.
Section 4.2 describes other options.
3. Interconnecting DC Virtual Network and External Networks
For customers (an enterprise or individuals) who want to utilize the DC
provider's compute and storage resources to run their applications,
they need to access their systems hosted in a DC through Internet or
Service Providers' WANs. A DC provider may construct an NVO3 a virtual
network which that connect all the resources designated for a customer connect to and
allow the customer to access their systems resources via the network. a virtual gateway
(vGW). This, in turn, becomes the case of interconnecting a DC NVO3
virtual network and external networks the network at customer site(s) via Internet or
WANs. Two cases are described here.
3.1. DC Virtual Network Access via Internet
A user or an enterprise customer connects securely can connect to a DC virtual network via Internet. Internet in a
secure way. Figure 1 illustrates this case. A virtual network is
configured on NVE1 and NVE2 and two NVEs are connected via an L3
tunnel in the Data Center. A set of tenant systems are attached to
NVE1 on a server. The NVE2 resides on a DC Gateway device. NVE2
terminates the tunnel and uses the VNID on the packet to pass the
packet to the corresponding VN GW vGW entity on the DC GW. A
user or customer can
access their systems, i.e. TS1 or TSn, in the DC via Internet by
using IPsec tunnel [RFC4301]. The IPsec tunnel is configured between
the VN GW vGW and the user or CPE customer gateway at enterprise edge location. customer site. Either static
route or BGP may be used for peer routes. The VN GW vGW provides IPsec
functionality such as authentication scheme and encryption, as well as the mapping to the right virtual network
entity on the DC GW. encryption. Note that
that: 1) some VN GW vGW functions such as firewall and load balancer may
also be performed by locally attached network appliance devices; 2)
The virtual network in DC may use different address space than
external users, then VN GW serves vGW need to provide the NAT function. function; 3) more
than one IPsec tunnels can be configured for the redundancy; 4) vGW
may be implemented on a server or VM. In this case, IP tunnels or
IPsec tunnels may be used over DC infrastructure.
Server+---------------+
| TS1 TSn |
| |...| |
| +-+---+-+ | External User Customer Site
| | NVE1 | | +-----+
| +---+---+ | | PC CGW |
+------+--------+ +--+--+
| *
L3 Tunnel *
| *
DC GW +------+---------+ .--. .--.
| +---+---+ | ( '* '.--.
| | NVE2 | | .-.' * )
| +---+---+ | ( * Internet )
| +---+---+. | ( * /
| | VNGW1 vGW | * * * * * * * * '-' '-'
| +-------+ | | IPsec \../ \.--/'
| +--------+ | Tunnel
+----------------+
DC Provider Site
Figure 1 DC Virtual Network Access via Internet
3.2. DC VN and Enterprise Sites interconnected via SP WAN
An Enterprise enterprise company would may lease some DC provider compute the VM and storage resources hosted
in the 3rd party DC to run some its applications. For example, the rd company may run its web applications at DC provider 3 party sites but run
backend applications in
their own DCs. The Web applications and backend rd applications need to communicate privately. The 3 party DC provider may
construct a NVO3 network one or more virtual networks to connect all VMs and
storage running the Enterprise Web applications. The
enterprise company may buy
a p2p private tunnel such as VPWS from a SP to interconnect its site
and the NVO3 virtual network in provider DC at the 3rd party site. A protocol is
necessary for exchanging the reachability between two peering points
and the traffic are carried over the tunnel. If an enterprise has
multiple sites, it may buy multiple p2p tunnels to form a mesh rd interconnection among the sites and DC provider the 3 party site. This requires
each site peering with all other sites for route distribution.
Another way to achieve multi-site interconnection is to use Service
Provider (SP) VPN services, in which each site only peers with SP PE
site. A DC Provider and VPN SP may build a NVO3 DC virtual network (VN)
and VPN independently. The VN provides the networking for all the related
TSes within the provider DC. The VPN interconnects several enterprise sites,
sites and the DC virtual network at DC site, i.e. VPN sites. site. The DC provider and VPN SP further
connect the
VN and VPN at the DC GW/ASBR and SP PE/ASBR. Several
options for the interconnection of the VN and VPN interconnect via a local link or a tunnel. The control
plan interconnection options are described in RFC4364 [RFC4364]. In
Option A with VRF-LITE [VRF-LITE], both DC GW and SP PE maintain the a
routing/forwarding table, and perform the table lookup in forwarding.
In Option B, DC GW and SP PE do not maintain the forwarding table,
it only maintains the VN and VPN identifier mapping, and exchange swap the
identifier on the packet in the forwarding process. Both option A
and B requires tunnel termination. In option C, DC GW and SP PE use
the same identifier for VN and VPN, and just perform the tunnel
stitching, i.e. change the tunnel end points. Each option has
pros/cons (see RFC4364) and has been deployed in SP networks
depending on the applications. The BGP protocols may be used in
these options for route distribution. Note that if the provider DC
is the SP Data Center, the DC GW and PE in this case may be on one
device.
This configuration allows the enterprise networks communicating to
the tenant systems attached to the VN in a provider DC without
interfering with DC provider underlying physical networks and other
virtual networks in the DC. The enterprise may use its own address
space on the tenant systems attached to in the VN. The DC provider can manage the VMs
which VM and storage attachment to the VN for the enterprise
customer. VN. The enterprise customer can determine and run their
manages what applications to run on the VMs. VMs in the VN. See section Section 4
for more.
The interesting feature in this use case is that the VN and compute
resource are managed by the DC provider. The DC operator can place
them at any location server without notifying the enterprise and WAN SP
because the DC physical network is completely isolated from the
carrier and enterprise network. Furthermore, the DC operator may
move the VMs assigned to the enterprise from one sever to another in
the DC without the enterprise customer awareness, i.e. no impact on
the enterprise 'live' applications running these resources. Such
advanced features bring DC providers great benefits in serving these
kinds of cloud
applications but also add some requirements for NVO3 [NVO3PRBM].
4. DC Applications Using NVO3
NVO3 brings DC operators the flexibility in designing and deploying
different applications in an end-to-end virtualization overlay
environment, where the operators not no longer need to worry about the
constraints of the DC physical network configuration in the Data Center. when creating
VMs and configuring a virtual network. DC provider may use NVO3 in
various ways and also use it in the conjunction with physical
networks in DC for many reasons. This section just highlights some
use cases but not limits to. cases.
4.1. Supporting Multi Technologies and Applications in a DC
Most likely servers deployed in a large data center are rolled in at
different times and may have different capacities/features. Some
servers may be virtualized, some may not; some may be equipped with
virtual switches, some may not. For the ones equipped with
hypervisor based virtual switches, some may support VxLAN [VXLAN]
encapsulation, some may support NVGRE encapsulation [NVGRE], and
some may not support any types of encapsulation. To construct a
tenant virtual network among these servers and the ToR switches, it may
construct one virtual network overlay and one virtual network
w/o overlay, traditional VLAN network; or
two virtual networks overlay with different
implementations. For example, that one virtual network overlay uses VxLAN encapsulation and another virtual network w/o overlay uses
traditional VLAN or another virtual network overlay
uses NVGRE.
The
In these cases, a gateway device or virtual gateway on a device may be used. The
gateway participates in GW is used to both
participate in multiple virtual networks. It performs the packet
encapsulation/decapsulation and may also perform address mapping or
translation, and etc.
A data center may be also constructed with multi-tier zones. Each
zone has different access permissions and run different applications.
For example, the three-tier zone design has a front zone (Web tier)
with Web applications, a mid zone (application tier) with service
applications such as payment and booking, and a back zone (database
tier) with Data. External users are only able to communicate with
the web Web application in the front zone. In this case, the
communication between the zones MUST pass through the security
GW/firewall. The One virtual network virtualization may be used configured in each zone. zone and
a GW is used to interconnect two virtual networks. If individual
zones use the different implementations, the GW needs to support
these implementations as well.
4.2. Tenant Network with Multi-Subnets or across multi DCs
A tenant network may contain multiple subnets. The DC operators may
construct multiple physical
network needs support the connectivity for many tenant networks. The access policy for inter-
subnets is often necessary. To benefit the policy management, the
inter-subnets policies may be placed at some designated gateway
devices only. Such design requires the inter-subnet traffic MUST to be
sent to one of the gateways first for the policy checking. However this checking, which may
cause traffic hairpin on at the gateway in a DC. It is desirable that
an NVE can hold some policy policies and be able to forward inter-subnet
traffic directly. To reduce NVE burden, the hybrid design may be
deployed, i.e. an NVE can perform forwarding for the selected inter-subnets inter-
subnets and the designated GW performs for the rest. For example,
each NVE performs inter-subnet forwarding for a tenant, and the
designated GW is used for inter-subnet traffic from/to the different
tenant networks.
A tenant network may span across multiple Data Centers in distance.
DC operators may want configure an L2VN L2 VN within each DC and L3VN an L3 VN
between DCs for a tenant network. L2 bridging has the simplicity and endpoint
awareness while L3 routing has advantages in policy based routing,
aggregation, and scalability. For this configuration, the
virtual L2/L3 gateway can be implemented on DC GW device. Figure 2
illustrates this configuration.
Figure 2 depicts two DC sites. The site A constructs an L2VN with one L2 VN, say
L2VNa, on NVE1, NVE2, and NVE3. NVE1 and NVE2 reside on the servers where the
which host multiple tenant systems are created. systems. NVE3 resides on the DC GW device.
The site Z has similar configuration with NVE3 and NVE4 L2VNz on the servers NVE3, NVE4, and NVE6 on the DC GW. An L3VN
NVE6. One L3 VN, say L3VNx, is configured between on the NVE5 at site A and
the NVE6 at site Z. An internal Virtual Integrated Interface of Routing and
Bridging (VIRB) is used between L2VNI and L3VNI on NVE5 and NVE6. NVE6,
respectively. The L2VNI is the MAC/NVE mapping table and the L3VNI
is the IP prefix/NVE mapping table. A packet to the NVE5 from L2VN L2VNa
will be decapsulated and converted into an IP packet and then
encapsulated and sent to the site Z. The policies can be checked at
VIRB.
Note that both the L2VNs L2VNa, L2VNz, and L3VN L3VNx in Figure 2 are encapsulated and
carried over within DC and across WAN networks, respectively. overlay
virtual networks.
NVE5/DCGW+------------+ +-----------+NVE6/DCGW
| +-----+ | '''''''''''''''' | +-----+ |
| |L3VNI+----+' L3VN L3VNx '+---+L3VNI| |
| +--+--+ | '''''''''''''''' | +--+--+ |
| |VIRB | | VIRB| |
| +--+---+ | | +---+--+ |
| |L2VNIs| | | |L2VNIs| |
| +--+---+ | | +---+--+ |
+----+-------+ +------+----+
''''|'''''''''' ''''''|'''''''
' L2VN L2VNa ' ' L2VN L2VNz '
NVE1/S ''/'''''''''\'' NVE2/S NVE3/S'''/'''''''\'' NVE4/S
+-----+---+ +----+----+ +------+--+ +----+----+
| +--+--+ | | +--+--+ | | +---+-+ | | +--+--+ |
| |L2VNI| | | |L2VNI| | | |L2VNI| | | |L2VNI| |
| ++---++ | | ++---++ | | ++---++ | | ++---++ |
+--+---+--+ +--+---+--+ +--+---+--+ +--+---+--+
|...| |...| |...| |...|
Tenant Systems Tenant Systems
DC Site A DC Site Z
Figure 2 Tenant Virtual Network with Bridging/Routing
4.3. Virtual Data Center (vDC)
Enterprise DC's today may often use several deploy routers, switches, and network
appliance devices to construct its internal network, DMZ, and
external network access. access and have many servers and storage running
various applications. A DC Provider may offer a virtual DC service
to an enterprise customers. A vDC provides the same capability as a
physical DC. A customer manages what and run enterprise how applications
such as website/emails as well. to run in
the vDC. Instead of using many hardware devices to do it, with the
network virtualization overlay technology, DC operators may build
such vDCs on top of a common
network DC infrastructure for many such
customers and run network service applications application per a vDC basis. vDC. The net network
service applications
such as may include firewall, DNS, load balancer can be designed per vDC. balancer,
gateway, etc. The network virtualization overlay further enables
potential for vDC mobility when a customer moves to different
locations because tenant
systems and net appliances vDC configuration can be completely is decouple from the
infrastructure network.
Figure 3 below illustrates one scenario. For the simple
illustration, it only shows the L3VN L3 VN or L2VN L2 VN as virtual and overlay routers or
switches. In this case, DC operators construct create several L2 VNs (L2VNx,
L2VNy, L2VNz) in Figure 3 to group the end tenant systems together per
application basis, create an L3VNa one L3 VN, e.g. VNa for the internal
routing. A net device (may be a VM or server) runs firewall/gateway
applications and connects to the L3VNa and Internet. A load Balancer balancer
(LB) is used in L2VNx. L2 VNx. A VPWS p2p tunnel is also built between the
gateway and enterprise router. The design
runs Enterprise customer runs
Web/Mail/Voice applications at the provider DC site; lets the users
at Enterprise site to access the applications via the VPN tunnel and
Internet via a gateway at the Enterprise site; let Internet users
access the applications via the gateway in the provider DC.
The Enterprise customer decides which applications are accessed by intranet
only and which by both intranet and extranet; DC operators
then design extranet and configure configures the
proper security policy and gateway function. Furthermore DC operators a customer
may use want multi-zones in a vDC for the security and/or set different
QoS levels for the different
applications based on customer applications.
This use case requires the NVO3 solution to provide the DC operator
an easy way to create a VN and NVEs for any design and to quickly
assign TSs to a VNI VNIs on a NVE they attach to, easily to set up virtual
topology and place or configure policies on an NVE or VMs that run
net services, and support VM mobility. Furthermore, Furthermore a DC operator needs
and/or customer should be able to view the tenant network topology
and know the
tenant node capability and is able to configure a net service on the tenant node. network functions. DC provider may further
let a tenant to manage the vDC itself.
Internet ^ Internet
|
^ +-+----+ +--+---+
| | GW |
| +--+---+
| |
+-------+--------+ +-+----+ +--+---+
|FireWall/Gateway+--- VPWS/MPLS---+Router| VPN-----+router|
+-------+--------+ +-+--+-+
| | |
...+...
...+.... |..|
+-----: L3VNa :--------+
+-------: L3 VNa :---------+ LANs
+-+-+ ....... ........ |
|LB | | | Enterprise Site
+-+-+ | |
...+... ...+... ...+...
: L2VNx : : L2VNy : : L2VNz L2VNx :
....... ....... .......
|..| |..| |..|
| | | | | |
Web Apps Mail Apps VoIP Apps
Provider DC Site
firewall/gateway and Load Balancer (LB) may run on a server or VMs
Figure 3 Virtual Data Center by Using NVO3
5. OAM Considerations
NVO3 brings the ability for a DC provider to segregate tenant
traffic. A DC provider needs to manage and maintain NVO3 instances.
Similarly, the tenant needs to be informed about underlying network
failures impacting tenant applications or the tenant network is able
to detect both overlay and underlay network failures and builds some
resiliency mechanisms.
Various OAM and SOAM tools and procedures are defined in [IEEE
802.1ag], [ITU-T Y.1731], [RFC4378], [RFC5880], [ITU-T Y.1564] for
L2 and L3 networks, and for user, including continuity check,
loopback, link trace, testing, alarms such as AIS/RDI, and on-demand
and periodic measurements. These procedures may apply to tenant
overlay networks and tenants not only for proactive maintenance, but
also to ensure support of Service Level Agreements (SLAs).
As the tunnel traverses different networks, OAM messages need to be
translated at the edge of each network to ensure end-to-end OAM.
6. Summary
The document describes some general potential use cases of NVO3 in
DCs. The combination of these cases should give operators
flexibility and capability to design more sophisticated cases for
various purposes.
DC services may vary from infrastructure as a service (IaaS),
platform as a service (PaaS), to software as a service (SaaS), in
which the network virtualization overlay is just a portion of an
application service. NVO3 decouples the service
construction/configurations from the DC network infrastructure
configuration, and helps deployment of higher level services over
the application.
NVO3's underlying network provides the tunneling between NVEs so
that two NVEs appear as one hop to each other. Many tunneling
technologies can serve this function. The tunneling may in turn be
tunneled over other intermediate tunnels over the Internet or other
WANs. It is also possible that intra DC and inter DC tunnels are
stitched together to form an end-to-end tunnel between two NVEs.
A DC virtual network may be accessed via an by external network users in a secure
way. Many existing technologies can help achieve this.
NVO3 implementation implementations may vary. Some DC operators prefer to use
centralized controller to manage tenant system reachbility in a
tenant network, other prefer to use distributed protocols to
advertise the tenant system location, i.e. attached associated NVEs. For the
migration and special requirement, the different solutions may apply
to one tenant network in a DC. When a tenant network spans across
multiple DCs and WANs, each network administration domain may use
different methods to distribute the tenant system locations. Both
control plane and data plane interworking are necessary.
7. Security Considerations
Security is a concern. DC operators need to provide a tenant a
secured virtual network, which means one tenant's traffic isolated
from the other tenant's traffic and non-tenant's traffic; they also
need to prevent DC underlying network from any tenant application
attacking through the tenant virtual network or one tenant
application attacking another tenant application via DC networks.
For example, a tenant application attempts to generate a large
volume of traffic to overload DC underlying network. The NVO3
solution has to address these issues.
8. IANA Considerations
This document does not request any action from IANA.
9. Acknowledgements
Authors like to thank Sue Hares, Young Lee, David Black, Pedro
Marques, Mike McBride, David McDysan, Randy Bush, and Uma Chunduri
for the review, comments, and suggestions.
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997
[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, February 2006.
[IEEE 802.1ag] "Virtual Bridged Local Area Networks - Amendment 5:
Connectivity Fault Management", December 2007.
[ITU-T G.8013/Y.1731] OAM Functions and Mechanisms for Ethernet
based Networks, 2011.
[ITU-T Y.1564] "Ethernet service activation test methodology", 2011.
[RFC4378] Allan, D., Nadeau, T., "A Framework for Multi-Protocol
Label Switching (MPLS) Operations and Management (OAM)",
RFC4378, February 2006
[RFC4301] Kent, S., "Security Architecture for the Internet
Protocol", rfc4301, December 2005
[RFC5880] Katz, D. and Ward, D., "Bidirectional Forwarding Detection
(BFD)", rfc5880, June 2010.
10.2. Informative References
[NVGRE] Sridharan, M., "NVGRE: Network Virtualization using Generic
Routing Encapsulation", draft-sridharan-virtualization-
nvgre-02, work in progress.
[NVO3PRBM] Narten, T., etc et al "Problem Statement: Overlays for
Network Virtualization", draft-ietf-nvo3-overlay-problem-
statement-02,
statement-03, work in progress.
[NVO3FRWK] Lasserre, M., Motin, T., and etc, et al, "Framework for DC
Network Virtualization", draft-ietf-nvo3-framework-02, draft-ietf-nvo3-framework-03,
work in progress.
[NVO3MCAST] Ghanwani, A., "Multicast Issues in Networks Using NVO3",
draft-ghanwani-nvo3-mcast-issues-00, work in progress.
[VRF-LITE] Cisco, "Configuring VRF-lite", http://www.cisco.com
[VXLAN] Mahalingam,M., Dutt, D., etc "VXLAN: A Framework for
Overlaying Virtualized Layer 2 Networks over Layer 3
Networks", draft-mahalingam-dutt-dcops-vxlan-03.txt, work
in progress.
Authors' Addresses
Lucy Yong
Huawei Technologies,
5340 Legacy Dr.
Plano, TX 75025
Phone: +1-469-277-5837
Email: lucy.yong@huawei.com
Mehmet Toy
Comcast
1800 Bishops Gate Blvd.,
Mount Laurel, NJ 08054
Phone : +1-856-792-2801
E-mail : mehmet_toy@cable.comcast.com
Aldrin Isaac
Bloomberg
E-mail: aldrin.isaac@gmail.com
Vishwas Manral
Hewlett-Packard Corp.
3000 Hanover Street, Building 20C
Palo Alto, CA 95014
Phone: 650-857-5501
Email: vishwas.manral@hp.com
Linda Dunbar
Huawei Technologies,
5340 Legacy Dr.
Plano, TX 75025 US
Phone: +1-469-277-5840
Email: linda.dunbar@huawei.com