Patent Description:
The subject matter of this disclosure relates in general to the field of computer networking, and more particularly, to systems and methods for software defined access fabric without subnet restriction within a virtual network.

An enterprise network can be seen as a communication backbone for the enterprise by connecting computers and other related computing devices across different locations. Furthermore, the enterprise network also provides the enterprise features for obtaining insight regarding the functioning of each computing device connected to the network as well as accessibility to the data associated with each of the computing devices as well.

Depending on the size of the enterprise network, the network itself can be broken up into smaller and more efficient subnetworks. Subnets can allow connected computing devices to communicate with each other within the subnet while utilizing routers to communicate between subnets. Sizes for the subnets can depend on various factors, for example, connectivity requirements and the network technology used with the enterprise network. One example advantage for having multiple subnets within a larger enterprise network is to improve address allocation efficiency and network address utilization. Furthermore the use of subnets can improve network performance and speed, reduce network congestion, ease administration, and control network growth. Other advantages of using subnets include setting up logical divisions that help maintain separation within the network and improved network security. Document <CIT>discloses virtual switch profiles that are assign properties that are used to map features and policies to specific ports on properties associated with the physical server. This allows a virtual machine attached to the same profile to have different active profiles based on the server on which the virtual machine is operating. This allows that a device be defined with dynamic policies within the network.

To provide a more complete understanding of the present disclosure and features and advantages thereof, reference is made to the following description, taken in conjunction with the accompanying drawings, in which:.

Disclosed herein are computer-implemented methods, computer-readable media, and systems for providing software defined access fabric without subnet restrictions to a virtual network. The methods, computer-readable media, and systems relate to receiving notifications from a switch that a host joined an enterprise network. The hosts are then assigned an address within a common subnet associated with the enterprise network. A policy is generated for the host based on the assigned address that includes assigning the host a role associated with the enterprise network (e.g. provider, subscriber). When a data packet transmission request is received at a later time, which includes identification of another host within the common subnet as a destination for the data packet, the generated policies are used to evaluate the request. Instructions are then provided to the switch based on the outcome of the evaluations. For example, if the data packet transmission request corresponds to allowed communication between the two different hosts within the same subnet outlined in the generated policies, instructions to the switch would allow the switch to carry out the data packet transmission. However, if the data packet transmission request corresponds to communications between two different hosts within the common subnet that are not permitted, instructions to the switch would instruct the switch to drop the data packet so that the transmission is not completed.

The detailed description set forth below is intended as a description of various configurations of embodiments and is not intended to represent the only configurations in which the subject matter of this disclosure can be practiced. The detailed description includes specific details for the purpose of providing a more thorough understanding of the subject matter of this disclosure. However, it will be clear and apparent that the subject matter of this disclosure is not limited to the specific details set forth herein and may be practiced without these details. In some instances, structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject matter of this disclosure.

Enterprises customers may desire a subnet to go to multiple devices with Layer-<NUM> underlay. However, many network implementations restrict a single virtual network (VN) to be associated with one subnet. For example, an enterprise customer with <NUM> sites (e.g., one site for each store associated with a retail enterprise customer) may wish to utilize the power of software defined access (SD Access) to manage, group, or separate the sites. SD Access is an intent-based networking solution for an enterprise network environment. The intent-based network treats the computing network as a single system that provides the translation and validation of the business intent (or goals) into the computing network and returns actionable insights. SD Access provides automated end-to-end services (such as segmentation, quality of service, analytics, and so on) for users, computing devices, and application traffic within the computing network. One feature of SD Access is that SD Access automates network user policies so organizations (e.g. enterprises) can ensure the appropriate access control and application experience are set for any user or device to any application across the network. This is accomplished using a single network fabric across a local area network (LAN) and wireless local area network (WLAN) which creates a consistent user experience, anywhere, without compromising on security.

As described herein, each of the sites may have multiple virtual networks (VNs). The enterprise customer may wish to keep the same subnet across all of the sites (which would include each of their respective virtual networks). The enterprise customer may also wish to have common shared resources or services (e.g., Dynamic Host Configuration Protocol (DHCP), Domain Name System (DNS), etc.) for all the sites. However, most current network implementations are unable to keep the same subnet across multiple sites and/or virtual networks thereby providing an embodiment where each subnet would have its own virtual network. The network hardware may also be unable to support the large number of virtual networks that comes with each site having multiple subnets.

Aspects of the subject technology addresses these restrictions and technical obstacles by describing a mechanism where a computing network (e.g., an enterprise fabric) can be provisioned with a common subnet across a number of subscribers while having dynamic network policies that isolate those subscribers from one another. The dynamic generation of the network policies is performed when a host (e.g. client) is detected (via a switch) as the host connects/joins the computing network. This ability to configure a common subnet for all the hosts (e.g. clients) of the Enterprise accessing external shared services while keeping the separation and segmentation of multiple subscribers and their respective virtual networks within a single subnet makes the Enterprise fabric more simple and convenient to deploy with shared service without any security compromise.

<FIG> illustrates an example enterprise network <NUM>. The enterprise network <NUM> may have an enterprise fabric that would be used by the enterprise to manage its different sites <NUM>. For example, the enterprise may be a retail customer that wants to be able to manage each of its individually franchised stores (each associated with a different site). Each site <NUM> may have computing devices (e.g. cashier system) that the enterprise would like to manage using the enterprise fabric <NUM>.

The management of the different sites <NUM>, using the enterprise fabric <NUM>, is performed at a single headquarter site <NUM>. Furthermore, by using the headquarter site <NUM>, the enterprise is also capable of sharing resources and services (for example, via a server at the headquarter site <NUM>) to each of the different sites <NUM>. <FIG> provides an example enterprise with <NUM> different sites. It should be noted that more or less sites can be present.

It may be desired by the enterprise that each of the sites be assigned to the same subnet <NUM> (e.g. common subnet). By having each of the sites assigned to the same subnet (as opposed to separate subnets), this simplifies the deployment and management for the different sites associated with the enterprise. As new sites are added and/or removed from the enterprise, these sites can be associated with the same subnet. There would be no need to track the different sites and their corresponding subnet addresses if the sites all are assigned to the same subnet.

Although having each of the different sites be managed by the same subnet would be a desired method of management, as illustrated in <FIG>, currently there are a number of issues that prevents the embodiment from being effective. Although the exemplary arrangement, illustrated in <FIG>, allows the enterprise to communicate between the headquarter site <NUM> with each of the different sites <NUM> associated with the enterprise fabric <NUM> assigned at the same subnet, the same can be said about communications between each of the sites <NUM> within the same subnet. Such communication between sites <NUM> within the same subnet of the enterprise fabric <NUM> can be performed, for example, via leaks or broadcasts/multi-cast packet transmission.

Each of the sites can be viewed as an independent entity (e.g. a store owned by a different franchise owner). As such, there may be no need or desire to each the sites be capable of communicating amongst each other. Furthermore, for the purposes of security, it would be desired that the sites <NUM> themselves be completely isolated from one another (e.g. incapable of communication between each other). Isolation of each of the sites could be possible, for example, if each of the sites <NUM> is assigned a different subnet whereby each of these subnets are assigned exclusively to a different virtual network. However, having each site be assigned to a different subnet would also further complicate the process of deploying the different sites and associated subnets as well as the management of the different sites and subnets in connection with the headquarter site <NUM>.

Another possible process for maintaining isolation between the different sites <NUM> within the same subnet <NUM> could be to use an access LISP (e.g. locator/identifier separation protocol). LISP is a network architecture and protocol that implements the use of two namespaces instead of a single IP address. The namespaces, known as endpoint identifiers (or EID), are associated with each of the end-hosts. The access LISP can then define which hosts (identified via their respective Internet Protocol (IP) addresses) can transmit and receive communications between themselves. The issue, however, is that hosts (and IP addresses) are generally not static. In order for the access LISP to work, each and every IP address for the different sites <NUM> associated with the common subnet of the enterprise fabric <NUM> would need to be known. Furthermore, the IP addresses for the different sites <NUM> cannot change. If, for some reason, some computing devices are moved from one site to a different site, the access LISP would be incapable of identifying if the IP addresses have been re-assigned properly and could potentially fail in managing the communication as originally intended.

Therefore, there is a need for a method that allows the sites to be associated with the same subnet but still have their respective isolation while using their respective virtual networks. The following figures describe in further detail how isolation is provided using some example embodiments.

<FIG> illustrates an example enterprise network <NUM> in accordance with an embodiment applying the principles of this disclosure. The example enterprise network <NUM> is similar to the enterprise network illustrated in <FIG> except for a couple of features. A first difference pertains to the implementation of various virtual networks (VNs) at each of the different sites <NUM> and the headquarter site <NUM>. The use of virtual networks would allow the enterprise network <NUM> to maintain isolation between sites. Subnets provide some isolation via logical division or separation of IP addresses. However, subnet addresses of one host can be routable to other hosts so complete isolation cannot be guaranteed.

Furthermore, the example enterprise network <NUM> also includes a new feature, a map server <NUM>. The map server <NUM> (described in further details below) will be used to dynamically generate and enforce network policies. The network policies will be used to define the allowable communication between each of the sites <NUM> and the headquarter site <NUM>. The network policies are dynamically generated each time a host joins and is detected within the network (e.g. enterprise fabric <NUM>). The dynamic generation of network policies provides greater flexibility as this allows for constantly changing environment (as hosts can join, leave, and re-join at any time). In the scenario that a computing device is taken offline, the previously assigned IP address for that computing device in connection with the enterprise fabric <NUM> is released and may be picked up by a different host connecting to the network at a subsequent time. If and when the computing device reconnects to the enterprise fabric <NUM>, if the computing device is assigned a new IP address, a new policy would also be created based on the new assignment.

The network (which will also be referred within disclosure as the enterprise fabric <NUM>) provides the capability for an enterprise to connect each of its computing devices so that it can communicate and be managed. As further described in <FIG>, the network includes various switches that facilitates different hosts in joining and communicating via the network.

Generally, the network (e.g. enterprise fabric <NUM>) can comprise a variety of different planes (not illustrated). For example, the network can comprise an orchestration plane, a management plane, a control plane, and a data plane.

The orchestration plane can assist in the automatic on-boarding of edge network devices (such as switches and routers) in an overlay network. The orchestration plane can include one or more physical or virtual network orchestrator appliances that perform the initial authentication of the edge network devices as well as provide connectivity between devices of the control plane and the data plane. In some embodiments, the network orchestrator appliances also enable communication of edge network devices located behind Network Address Translation (NAT). Exemplary network orchestrator appliances that may be used with the present disclosure may include, for example, physical or virtual Cisco@ SD-WAN vBond appliances and Cisco@ DNA Center.

The management plane can be responsible for central configuration and monitoring of the network. The management plane can include one or more physical or virtual network management appliances that provide centralized management of the network via a graphical user interface (GUI). The GUI allows a user to monitor, configure, and maintain the edge network devices and links (e.g. Internet transport network, multi-protocol label switching (MPLS) network, <NUM>/LTE network) in an underlay and overlay network. The network management appliances can also support multi-tenancy and enable centralized management of logically isolated networks associated with different entities (e.g. enterprises, divisions within enterprises, groups within divisions, etc.). Alternatively or in addition, the network management appliance(s) can be a dedicated network management system for a single entity. In some embodiments, physical or virtual Cisco@ SD-WAN vManage appliances and Cisco@ DNA Center can operate as the network management appliance(s).

The control plane can build and maintain a network topology and make decisions on where traffic flows within the network. The control plane can include one or more physical or virtual network controller appliances. The network controller appliances can establish secure connections to each network device and distribute route and policy information via a control plane protocol (e.g., Overlay Management Protocol (OMP), Open Shortest Path First (OSPF), Intermediate System to Intermediate System (IS-IS), Border Gateway Protocol (BGP), Protocol-Independent Multicast (PIM), Internet Group Management Protocol (IGMP), Internet Control Message Protocol (ICMP), Address Resolution Protocol (ARP), Bidirectional Forwarding Detection (BFD), Link Aggregation Control Protocol (LACP), etc.). In some embodiments, the network controller appliances can operate as route reflectors. The network controller appliances can also orchestrate secure connectivity in the data plane between and among the edge network devices. For example, in some embodiments, the network controller appliances can distribute crypto key information among the network devices <NUM>. This can allow the network to support a secure network protocol or application (e.g., Internet Protocol Security (IPSec), Transport Layer Security (TLS), Secure Shell (SSH), etc.) without Internet Key Exchange (IKE) and enable scalability of the network. In some embodiments, physical or virtual Cisco@ SD-WAN vSmart controllers can operate as the network controller appliances.

The data plane can be responsible for forwarding packets based on decisions from the control plane. The data plane can include the edge network devices, which can be physical or virtual network devices. The edge network devices can operate at the edges various network environments of an enterprise, such as in one or more data centers or colocation centers, campus networks, branch office networks, home office networks, and so forth, or in the cloud (e.g., Infrastructure as a Service (IaaS), Platform as a Service (PaaS), SaaS, and other cloud service provider networks). The edge network devices can provide secure data plane connectivity among sites over one or more WAN transports, such as via one or more Internet transport networks (e.g., Digital Subscriber Line (DSL), cable, etc.), MPLS networks (or other private packet-switched network (e.g., Metro Ethernet, Frame Relay, Asynchronous Transfer Mode (ATM), etc.), mobile networks (e.g., <NUM>, <NUM>/LTE, <NUM>, etc.), or other WAN technology (e.g., Synchronous Optical Networking (SONET), Synchronous Digital Hierarchy (SDH), Dense Wavelength Division Multiplexing (DWDM), or other fiber-optic technology; leased lines (e.g., T1/E1, T3/E3, etc.); Public Switched Telephone Network (PSTN), Integrated Services Digital Network (ISDN), or other private circuit-switched network; small aperture terminal (VSAT) or other satellite network; etc.). The edge network devices can be responsible for traffic forwarding, security, encryption, quality of service (QoS), and routing (e.g., BGP, OSPF, etc.), among other tasks. In some embodiments, physical or virtual Cisco@ SD-WAN vEdge routers can operate as the edge network devices.

The map server <NUM> will be used to dynamically define the relationship between the headquarter site <NUM> and each of the sites <NUM> within the enterprise network <NUM>. Specifically, the headquarter site <NUM> will be identified, via the policies, as a provider. Each of the sites <NUM> will be identified as individual subscribers.

The map server <NUM> is able to implement the isolation between the different sites <NUM> by generating site-specific policies that only allow communications to be transmitted between a particular site within the subnet with the headquarter site, namely only communications between sites having different roles (e.g. between the provider virtual network and a subscriber virtual network) are allowed. Each of these policies are generated as different entities join and are detected within the same subnet <NUM>. By using the dynamically generated policies, the map server <NUM> can be used to detect and deny requests corresponding to communications between subscriber sites using the same subnet.

As illustrated in the figure, the map server <NUM> can be its own separate entity with respect the enterprise fabric <NUM>. However, there may be other embodiments whereby the map server <NUM> can be part of the headquarters site <NUM> or part of the enterprise fabric <NUM> itself (e.g. switches/nodes).

An example network policy command line interface (CLI) is provided below. The network policy command is able to be provided dynamic capabilities with the use of an 'ip-any' keyword which allows the map server <NUM> to generate policies for any IP address that is detected within the subnet <NUM>.

For the above exemplary policy, the following notes are provided:.

<FIG> illustrate exemplary flow diagrams for a network management system in accordance with an embodiment. Specifically, <FIG> illustrates exemplary flows showing the detection of each host and subsequently dynamically generating network policies for the enterprise network; <FIG> illustrates exemplary flows showing allowable communication between a subscriber and the provider; and <FIG> illustrates exemplary flows showing what occurs when a non-permitted communication is detected between two subscribers.

With reference to <FIG>, the exemplary flow diagram includes a number of different entities that are used in connection with the network management system. These entities communicate with each other via messages as the different hosts are detected, the policies are dynamically generated for the detected hosts, determining whether a communication is appropriate, and transmission of the data packets if such communication is allowed. The exemplary entities include the map server <NUM>, each of the hosts <NUM>, <NUM>, <NUM>, and their associated switches <NUM>, <NUM>, and <NUM>.

The map server <NUM> is responsible for dynamically generating and storing the network policies. The policies, as described above, are used in the present disclosure to maintain isolation between the different subscribers within the subnet. These policies are generated when hosts join and are detected in the network.

Each of the hosts <NUM>, <NUM>, and <NUM> correspond to different sites that are associated with the network. Each host <NUM>, <NUM>, <NUM> is identified by their respective endpoint identifiers (EIDs), which in this case would be an IP address. The hosts <NUM>, <NUM>, <NUM> join the network, are detected, and registered with the network via their respective switches <NUM>, <NUM>, <NUM>.

With message [<NUM>], the map server <NUM> can be configured to define the relationship of which hosts are able to communicate with one another within the enterprise fabric. It is here that the map server <NUM> is configured to define the headquarter site (illustrated as H1 in <FIG>) as the provider and that the headquarter site would be allowed to communicate with any of the other hosts (defined as different subscribers). The map server <NUM> is also configured, at this point, to register any subsequent hosts (and their respective IP addresses) that join the enterprise fabric and are detected by the switches as being subscribers. These subscribers would not be allowed to communicate between each other using the generated network policies.

The identification of which host should be identified as the provider and which hosts are identified as subscribers can be carried out, for example, by having the map server be configured to identify which virtual networks are associated with the provider and which virtual networks are associated with subscribers. Hosts that need shared services would be instructed to connect to the enterprise fabric using virtual networks specific to subscribers. In contrast, hosts that are associated with the shared services server (e.g. headquarter site) will be instructed to connect using virtual networks specific to the provider.

As hosts join and leave the enterprise fabric, the map server <NUM> will automatically detect the IP addresses of these hosts and dynamically generate corresponding policies that allows the new subscribers to communicate with the headquarter site (e.g. provider). If for some reason a host leaves the enterprise fabric the previously assigned IP address can be released back and associated policies are deleted (so the old IP address can be reused for the next host joining the enterprise fabric). When that host rejoins, it may be re-assigned a new IP address and correspondingly be associated with new policies that are generated. In this way, the dynamic policies are available to prevent any subscribers (e.g. new or existing) from communicating with other subscribers that are currently associated with the same subnet of the enterprise fabric. The map server <NUM> and its associated policies can institute and maintain the desired isolation between the different hosts/sites that have virtual networks associated with the same subnet.

With messages [<NUM>], [<NUM>], and [<NUM>], the host (e.g. site) sends a message to their respective switch <NUM>, <NUM>, <NUM>. These messages [<NUM>], [<NUM>], and [<NUM>] are detected by the switches <NUM>, <NUM>, <NUM> as the hosts joining the enterprise network. The switches <NUM>, <NUM>, <NUM> can communicate with the map server <NUM> via messages [<NUM>], [<NUM>], and [<NUM>] in order to register the detected host with the map server <NUM>. Based on the initial definition of the relationships provided in message [<NUM>], the hosts will have their identification (e.g. IP addresses) added to the policies stored therein.

For example, when host2 <NUM> joins the enterprise fabric and is detected via message [<NUM>] by the corresponding switch (xTR2) <NUM>, the switch (xTR2) <NUM> can then register the host2 <NUM> at the map server <NUM>. In some embodiments, the map server <NUM> may require validation of authentication keys to determine whether the host2 <NUM> is allowed within the subnet based on possible definitions provided in message [<NUM>]. When the map server <NUM> allows host2 <NUM> to be registered, based on the definition provided in message [<NUM>], host2 may be defined as a subscriber within the enterprise fabric. The map server <NUM> will generate a corresponding policy that would allow host <NUM> to communicate with only the host identified as the provider (which would be host1 <NUM>) as illustrated in <FIG>). A policy is generated by the map server <NUM> whenever a new host joins the enterprise fabric. Even when a host leaves and re-joins the enterprise fabric, if the host is assigned a different identifier (e.g. IP address), the policies within the map server <NUM> would account for that by generating a new policy for that host.

<FIG> illustrates the messages that are sent when two hosts (specifically host that has been defined as a provider and a different host that is defined as a subscriber) attempt to communicate with each other within the enterprise fabric. In particular, message [<NUM>] - message [<NUM>] illustrates the steps to determine whether a communication from Host <NUM><NUM> can be provided to Host <NUM><NUM>. Meanwhile, messages [<NUM>] - [<NUM>] provide the reverse scenario illustrating the steps to determine whether a communication from Host <NUM><NUM> can be provided to Host <NUM><NUM>.

In the figure, Host <NUM><NUM> and Host <NUM><NUM> wish to communicate with each other via the enterprise fabric. Message [<NUM>] illustrates that a data packet is being provided from Host <NUM><NUM> (which is defined as a provider) to its respective switch (xTR1) <NUM>. The packet indicates that the source is coming from Host <NUM><NUM> and would like to be provided to Host <NUM><NUM> as the destination. Upon receiving the data packet from Host <NUM><NUM>, the switch (xTR1) <NUM> sends message [<NUM>] to the map server <NUM>.

Message [<NUM>] is provided to the map server <NUM> to identify whether the communication between Host <NUM><NUM> and Host <NUM><NUM> is appropriate based on the network policies at the map server <NUM>. If there is a generated policy within the map server <NUM> that approves that the communication between Host <NUM><NUM> and Host <NUM><NUM> is appropriate, the map server <NUM> provides IP address of Host <NUM><NUM> back to the switch (xTR1) <NUM> via message [<NUM>] so that the switch (xTR1) <NUM> knows where to transmit the data packet.

Once confirmation that communication can be performed between Host <NUM><NUM> and Host <NUM><NUM>, the data packet is encapsulated so that it can be provided to Host <NUM><NUM> via message [<NUM>]. The data packet is encapsulated, for example, to provide encryption so that the data packet can be transmitted safely and securely across the enterprise fabric. The encapsulated data packet is delivered from the switch (xTR1) associated with Host <NUM><NUM> to the switch (xTR2) <NUM> associated with Host <NUM><NUM>. Once received at the switch (xTR2) <NUM>, the data packet is de-capsulated and provided to the destination Host <NUM><NUM> as originally intended via message [<NUM>].

In connection with the latter half of <FIG>, the reverse scenario whereby Host <NUM><NUM> would attempt to communicate with Host <NUM><NUM> is described. Message [<NUM>] illustrates that a data packet is being provided by Host <NUM><NUM> to its respective switch (xTR2) <NUM>. The data packet provides information pertaining to the source being associated with Host <NUM><NUM> and the desired destination of Host <NUM><NUM>. The switch (xTR2) <NUM> then provides message [<NUM>] to the map server <NUM> to determine whether the data packet can be transmitted to Host <NUM><NUM>.

The map server <NUM> would evaluate each of the policies stored therein to ensure that Host <NUM><NUM> is not attempting to communicate with a different host that is also defined as a subscriber. Because the map server <NUM> would be able to identify that Host <NUM><NUM> is actually the provider associated with the enterprise network based on the stored policies, the map server <NUM> can provide confirmation back (via message [<NUM>]) that the data packet can be transmitted from Host <NUM><NUM> to Host <NUM><NUM>. Once the confirmation has been received via message [<NUM>], the data packet can be similarly encapsulated for security purposes and sent to the switch (xTR1) associated with Host <NUM><NUM> via message [<NUM>]. The data packet is then de-capsulated and provided to Host <NUM><NUM> via message [<NUM>].

For reference, the dotted line <NUM> illustrates that communication between Host <NUM><NUM> (which is defined as a provider) would be allowed with Host <NUM><NUM> (which is defined as a subscriber) based on the policies generated and stored within the map server <NUM>. At least within this embodiment, the generated policies stored within the map server <NUM> are used to ensure that a provider and a subscriber are the two entities seeking to communicate with each other via the enterprise fabric.

In connection with <FIG>, example scenarios are described where two hosts (defined as subscribers within the same subnet) attempt to communicate with each other. Here, the map server <NUM> utilizes the policies to prevent such communication so that isolation can be enforced between the two hosts. In particular, messages [<NUM>]-[<NUM>] are directed to attempts by Host <NUM><NUM> to communicate with Host <NUM><NUM> while messages [<NUM>]-[<NUM>] are directed to attempts by Host <NUM><NUM> to communicate with Host <NUM><NUM>.

With message [<NUM>], a data packet is being provided from Host <NUM><NUM> to switch (xTR2) <NUM>. The data packet includes information such as the source (being Host <NUM><NUM>) and the destination being Host <NUM><NUM>. The switch (xTR2) <NUM> will communicate with the map server <NUM> (via message [<NUM>]). Here the map server <NUM> will review the policies to determine if communication between Host <NUM><NUM> and Host <NUM><NUM> is allowed. Whereas, in <FIG>, communication was being performed between a provider and a subscriber within the enterprise fabric, here the map server <NUM> concludes that Host <NUM><NUM> is attempting to communicate with another subscriber Host <NUM><NUM>. This conclusion is reached by identifying that both Host <NUM><NUM> and Host <NUM><NUM> have been defined as subscribers within the same subnet and based on the initial definition (provided in message [<NUM>] of <FIG>), such a communication would not be allowed within the present enterprise fabric. Therefore the map server <NUM> provides a negative reply back via message [<NUM>]. This negative reply instructs the data packet to be dropped by the switch (xTR2) <NUM> so that it cannot be sent to Host <NUM><NUM>.

In the scenario where a data packet is being provided from Host <NUM><NUM> to its switch (xTR3) <NUM> via message [<NUM>] providing information that the data packet is intended for Host <NUM><NUM>, the switch (xTR3) <NUM> would communicate with the map server <NUM> to determine whether such communication would be appropriate (via message [<NUM>]). Similar to the scenario described above, the map server <NUM> will notice, based on the stored network policies, that Host <NUM><NUM> is attempting to communicate with another subscriber within the same subnet. Therefore, the map server <NUM> will again provide a negative reply back via message [<NUM>]. This negative reply instructs the data packet to be dropped by the switch (xTR3) <NUM> so that it cannot be sent to Host <NUM><NUM>.

For reference, the dotted line <NUM> illustrates that communication between Host <NUM><NUM> (which is defined as a subscriber) is not allowed with other subscribers (e.g. Host <NUM><NUM>) based on the policies generated and stored within the map server <NUM>. At least within this embodiment, the generated policies stored within the map server <NUM> are used to institute and maintain the isolation between different sites/hosts. By forcing the data packets to be dropped in this manner, the map server <NUM> can maintain isolation between subscribers within the same subnet while still allowing each subscriber to communicate with the provider as needed.

<FIG> illustrates an example method <NUM> according to an aspect of this disclosure. The method <NUM> describes the various steps for establishing an enterprise fabric that allows for multiple sites (defined as subscribers) to co-exist within the same subnet while still maintaining isolation between the different sites. Furthermore, each of the subscribers would still be allowed to communicate with the headquarter site (defined as the provider) within the enterprise fabric with the headquarter site also being capable of sharing resources and services with each of the subscribers.

In step <NUM>, the map server is configured to allow only communication between a provider and a subscriber within the enterprise fabric. Furthermore, the map server can also be configured to allow certain hosts to connect to the enterprise fabric and may also determine what hosts can be defined as being the provider. Here, the use of 'ip-any' prefixes within the map server provides for a dynamic learning environment where valid hosts (defined as subscribers) would be provided a specific policy that would allow those hosts to communicate with the provider and to have resources and services from the provider shared.

In step <NUM>, the enterprise fabric detects the hosts as they join the enterprise network. The hosts are detected when they communicate with switches that provide the hosts access to the enterprise network.

The switches then forward the host information to the map server in step <NUM>. While at the map server, validation can be performed to determine if the host is allowed to access the enterprise network. If authorized, the host can be assigned an IP address within a subnet. Based on the initial configuration of the map server in step <NUM>, the host can be defined as either the provider or a subscriber. If identified as a subscriber for the enterprise fabric, policies will be dynamically generated describing that the host would only be allowed to communicate with the host defined as the provider. Any other communications (e.g. subscriber to another subscriber) will be denied. The map server and its generated policies are used to maintain the isolation between the different hosts/subscribers within the same subnet.

Because the policies can be generated as hosts join the enterprise fabric, if for some reason one or more hosts leave and re-join at a later time, new policies would be created for these hosts. This allows for coverage of scenarios where hosts are assigned different IP addresses thereby providing policies that are dynamic based on the circumstances associated with the enterprise fabric.

In step <NUM>, data packet transmission request can be provided. In particular, a host may provide a data packet to a switch so that it can be transmitted to another host within the enterprise fabric.

When the data packet is received by the switch, the switch communicates with the map server in step <NUM> in order to determine whether the transmission request/communication is appropriate. The policies generated in step <NUM> will detail which host (e.g. subscriber) which host (e.g. provider) can be communicated with. Based on the policies stored within the map server, the map server would provide an appropriate response in step <NUM>.

If the data packet is indeed between a source host defined as a subscriber and a destination host defined as a provider, the map server will provide confirmation that the transmission can continue. The data can then be transmitted between the two hosts. However, if the data packet is determined to attempt transmission between two hosts that are defined as subscribers within the same subnet, the map server would provide instructions for the data packet to be dropped (e.g. the transmission is not completed).

By using the embodiment described above in the example method <NUM>, an enterprise would be capable of having multiple sites associated with the same subnet allowing a headquarter site to manage and share resources/services with each of those sites efficiently. Furthermore, the map server and its dynamically generated policies would provide the isolation (and security) between the different sites/subscribers by preventing these sites from communicating amongst themselves.

<FIG> illustrate examples of systems in accordance with some embodiments. The example systems can be implemented, for example, with respect to the provider/headquarter site and each of the subscribers/sites as illustrated in <FIG> and <FIG>.

<FIG> illustrates an example of a bus computing system <NUM> wherein the components of the system are in electrical communication with each other using a bus <NUM>. The computing system <NUM> can include a processing unit (CPU or processor) <NUM> and a system bus <NUM> that may couple various system components including the system memory <NUM>, such as read only memory.

(ROM) <NUM> and random access memory (RAM) <NUM>, to the processor <NUM>. The computing system <NUM> can include a cache <NUM> of high-speed memory connected directly with, in close proximity to, or integrated as part of the processor <NUM>. The computing system <NUM> can copy data from the memory <NUM>, ROM <NUM>, RAM <NUM>, and/or storage device <NUM> to the cache <NUM> for quick access by the processor <NUM>. In this way, the cache <NUM> can provide a performance boost that avoids processor delays while waiting for data. These and other modules can control the processor <NUM> to perform various actions. Other system memory <NUM> may be available for use as well. The memory <NUM> can include multiple different types of memory with different performance characteristics. The processor <NUM> can include any general purpose processor and a hardware module or software module, such as module <NUM><NUM>, module <NUM><NUM>, and module <NUM><NUM> stored in the storage device <NUM>, configured to control the processor <NUM> as well as a special-purpose processor where software instructions are incorporated into the actual processor design. The processor <NUM> may essentially be a completely self-contained computing system, containing multiple cores or processors, a bus, memory controller, cache, etc. A multi-core processor may be symmetric or asymmetric.

To enable user interaction with the computing system <NUM>, an input device <NUM> can represent any number of input mechanisms, such as a microphone for speech, a touch-protected screen for gesture or graphical input, keyboard, mouse, motion input, speech and so forth. An output device <NUM> can also be one or more of a number of output mechanisms known to those of skill in the art. In some instances, multimodal systems can enable a user to provide multiple types of input to communicate with the computing system <NUM>. The communications interface <NUM> can govern and manage the user input and system output. There may be no restriction on operating on any particular hardware arrangement and therefore the basic features here may easily be substituted for improved hardware or firmware arrangements as they are developed.

The storage device <NUM> can be a non-volatile memory and can be a hard disk or other types of computer readable media which can store data that are accessible by a computer, such as magnetic cassettes, flash memory cards, solid state memory devices, digital versatile disks, cartridges, random access memory, read only memory, and hybrids thereof.

As discussed above, the storage device <NUM> can include the software modules <NUM>, <NUM>, <NUM> for controlling the processor <NUM>. Other hardware or software modules are contemplated. The storage device <NUM> can be connected to the system bus <NUM>. In some embodiments, a hardware module that performs a particular function can include a software component stored in a computer-readable medium in connection with the necessary hardware components, such as the processor <NUM>, bus <NUM>, output device <NUM>, and so forth, to carry out the function.

<FIG> illustrates an example architecture for a chipset computing system <NUM> that can be used in accordance with an embodiment. The computing system <NUM> can include a processor <NUM>, representative of any number of physically and/or logically distinct resources capable of executing software, firmware, and hardware configured to perform identified computations. The processor <NUM> can communicate with a chipset <NUM> that can control input to and output from the processor <NUM>. In this example, the chipset <NUM> can output information to an output device <NUM>, such as a display, and can read and write information to storage device <NUM>, which can include magnetic media, solid state media, and other suitable storage media. The chipset <NUM> can also read data from and write data to RAM <NUM>. A bridge <NUM> for interfacing with a variety of user interface components <NUM> can be provided for interfacing with the chipset <NUM>. The user interface components <NUM> can include a keyboard, a microphone, touch detection and processing circuitry, a pointing device, such as a mouse, and so on. Inputs to the computing system <NUM> can come from any of a variety of sources, machine generated and/or human generated.

The chipset <NUM> can also interface with one or more communication interfaces <NUM> that can have different physical interfaces. The communication interfaces <NUM> can include interfaces for wired and wireless LANs, for broadband wireless networks, as well as personal area networks. Some applications of the methods for generating, displaying, and using the technology disclosed herein can include receiving ordered datasets over the physical interface or be generated by the machine itself by the processor <NUM> analyzing data stored in the storage device <NUM> or the RAM <NUM>. Further, the computing system <NUM> can receive inputs from a user via the user interface components <NUM> and execute appropriate functions, such as browsing functions by interpreting these inputs using the processor <NUM>.

It will be appreciated that computing systems <NUM> and <NUM> can have more than one processor <NUM> and <NUM>, respectively, or be part of a group or cluster of computing devices networked together to provide greater processing capability.

In summary, systems, methods, and computer-readable storage media are provided for provisioning a common subnet across a number of subscribers and their respective virtual networks using dynamically generated network policies that provide isolation between the subscribers. The dynamic generation of the network policies is performed when a host (e.g. client) is detected (via a switch) as the host joins the computing network via virtual networks. This ability to configure a common subnet for all the subscriber virtual networks allows these subscribers to more easily access external shared services coming from a headquarter site while keeping the separation and segmentation of multiple subscriber virtual networks within a single subnet. This allows the Enterprise fabric to be more simple and convenient to deploy without making security compromises.

For clarity of explanation, in some instances the various embodiments may be presented as including individual functional blocks including functional blocks comprising devices, device components, steps or routines in a method embodied in software, or combinations of hardware and software.

Some examples of such form factors include general purpose computing devices such as servers, rack mount devices, desktop computers, laptop computers, and so on, or general purpose mobile computing devices, such as tablet computers, smart phones, personal digital assistants, wearable devices, and so on.

Claim 1:
A method comprising:
receiving a notification from a switch that a first host (<NUM>) joined an enterprise network (<NUM>, <NUM>);
assigning the first host an address within a common subnet associated with the enterprise network;
generating a policy for the first host based on the assigned address, wherein the generated policy includes assigning to the first host a role associated with the common subnet, wherein the role is a subscriber;
receiving a transmission request for a data packet, wherein the request includes identification of a second host (<NUM>) within the common subnet as a destination for the data packet;
evaluating the data packet transmission request based on the generated policy for the first host (<NUM>); and
in response to the evaluation indicating that the first host (<NUM>) and the second host (<NUM>) are both subscribers within the common subnet, providing instructions to the switch to instruct the switch to drop the data packet.