Patent Application
20170093685
The present disclosure generally relates to generation of service-optimized paths based on Enhanced Interior Gateway Routing Protocol (EIGRP) telemetry.
This section describes approaches that could be employed, but are not necessarily approaches that have been previously conceived or employed. Hence, unless explicitly specified otherwise, any approaches described in this section are not prior art to the claims in this application, and any approaches described in this section are not admitted to be prior art by inclusion in this section.
The Enhanced Interior Gateway Routing Protocol (EIGRP) is a distance vector-based routing protocol that enables EIGRP-enabled routers to initially exchange routing information, enabling each EIGRP router to identify its neighboring topology (i.e., its next-hop neighbors). Once an EIGRP router has established its corresponding topology table (identified destination addresses reachable via next-hop neighbors) and routing table (e.g., based on the Diffusing Update Algorithm (DUAL)), an EIGRP router only needs to send an EIGRP-based update message only if a link transition occurs that affects the network topology. Unlike link-state routing protocols (e.g., Intermediate System to Intermediate System (IS-IS) or Open Shortest Path First (OSPF)), an EIGRP router is not aware of the network topology beyond its adjacent neighbor.
Segment Routing (SR) enables a network node to select an explicit path for a traffic class. Segment routing relies on a set of “segments” that are advertised by link-state routing protocols such as IS-IS or OSPF. A nodal segment represents a multi-hop path to a node, and an adjacency segment represents a single-hop path to an adjacent node. Segments act as topological sub-paths that can be combined together to form an explicit path to a destination.
Reference is made to the attached drawings, wherein elements having the same reference numeral designations represent like elements throughout and wherein:
In one embodiment, a method comprises an Enhanced Interior Gateway Routing Protocol (EIGRP) route server device receiving an EIGRP update message that includes telemetry information associated with an EIGRP router, the telemetry information including service-based attributes associated with the telemetry information; and the EIGRP route server device generating one or more service-optimized paths for reaching a destination network device based on the telemetry information, enabling any EIGRP router to reach the destination network device according to an identified service type based on the one or more service-optimized paths.
In another embodiment, an apparatus comprises a device interface circuit and a processor circuit. The device interface circuit is configured for receiving an EIGRP update message that includes telemetry information associated with an EIGRP router, the telemetry information including service-based attributes associated with the telemetry information. The processor circuit is configured for generating one or more service-optimized paths for reaching a destination network device based on the telemetry information, enabling any EIGRP router to reach the destination network device according to an identified service type based on the one or more service-optimized paths.
In another embodiment, one or more non-transitory tangible media are encoded with logic for execution by a machine and when executed by the machine operable for: receiving an EIGRP update message that includes telemetry information associated with an EIGRP router, the telemetry information including service-based attributes associated with the telemetry information; and generating one or more service-optimized paths for reaching a destination network device based on the telemetry information, enabling any EIGRP router to reach the destination network device according to an identified service type based on the one or more service-optimized paths.
In another embodiment, an apparatus comprises a processor circuit and a device interface circuit. The processor circuit is configured for generating an Enhanced Interior Gateway Routing Protocol (EIGRP) update message that includes telemetry information generated by the processor circuit based on detected attributes associated with the apparatus. The device interface circuit is configured for outputting the EIGRP update message to an adjacent router device, for generation of a service-optimized path for reaching a destination network device.
Particular embodiments enable generation of service-optimized paths in a data network based on EIGRP telemetry information associated with an EIGRP router, where the telemetry information includes service-based attributes that enable an EIGRP route server device to generate the service-optimized paths for reaching a destination network device according to one or more identified service types. An EIGRP router can detect the telemetry information, including for example service-based attributes allocated to the EIGRP router, topology information associated with the EIGRP router, etc., and add the telemetry information to an EIGRP update message output by the EIGRP router.
An EIGRP route server device, in response to receiving the EIGRP update message containing the telemetry information, can generate a service-based topology map of identified EIGRP routers that includes the topology information of the identified EIGRP routers relative to the associated service-based attributes; the EIGRP route server device also can generate one or more of the service-optimized paths for one or more identified service types, enabling any EIGRP router to reach a destination network device according to an identified service type based on a service-optimized path.
Hence, the example embodiments enable the deployment of service-optimized paths in a network using EIGRP router devices that can advertise, to an EIGRP route server, selected telemetry information including service-based attributes, topology information (e.g., Segment-Routing local information such as topology and Segment Identifiers (IDs) specific to an EIGRP router device), etc. The advertisement by the EIGRP router devices using EIGRP update messages containing telemetry information enables an EIGRP based network to become topology-aware and service-class aware. Further collection of telemetry information for EIGRP router devices beyond a summary point in a network can be executed by a PCE or equivalent device.
The EIGRP route server device 12 can receive the EIGRP update message 20 from one or more of the EIGRP routers “R1, “R2”, “R3”, “R4”, and/or “R5” 14. Although
The EIGRP route server device 12, in response to receiving an EIGRP update message 20, can store the EIGRP information 24 and telemetry information 22 in a segment routing database (SRDB) 26. As described in further detail with respect to
Hence, the EIGRP route server device 12 (and/or a Path Computation Element (PCE)) can generate one or more service-optimized paths (16 of
Hence, the example embodiments enable EIGRP update messages 20 to transmit telemetry information 22 that enable generation of service-optimized paths for reaching a destination, for example generation of Segment Routing based paths that are optimized for reaching a destination network device according to an identified service type.
Each apparatus 12, 24, and/or 26 can include a device interface circuit 32, a processor circuit 34, and a memory circuit 36. The device interface circuit 32 can include one or more distinct physical layer transceivers for communication with any one of the other devices 12, 24, and/or 26; the device interface circuit 32 also can include an IEEE based Ethernet transceiver for communications with the devices of
Any of the disclosed circuits of the devices 12, 24, and/or 26 (including the device interface circuit 32, the processor circuit 34, the memory circuit 36, and their associated components) can be implemented in multiple forms. Example implementations of the disclosed circuits include hardware logic that is implemented in a logic array such as a programmable logic array (PLA), a field programmable gate array (FPGA), or by mask programming of integrated circuits such as an application-specific integrated circuit (ASIC). Any of these circuits also can be implemented using a software-based executable resource that is executed by a corresponding internal processor circuit such as a microprocessor circuit (not shown) and implemented using one or more integrated circuits, where execution of executable code stored in an internal memory circuit (e.g., within the memory circuit 36) causes the integrated circuit(s) implementing the processor circuit to store application state variables in processor memory, creating an executable application resource (e.g., an application instance) that performs the operations of the circuit as described herein. Hence, use of the term “circuit” in this specification refers to both a hardware-based circuit implemented using one or more integrated circuits and that includes logic for performing the described operations, or a software-based circuit that includes a processor circuit (implemented using one or more integrated circuits), the processor circuit including a reserved portion of processor memory for storage of application state data and application variables that are modified by execution of the executable code by a processor circuit. The memory circuit 36 can be implemented, for example, using a non-volatile memory such as a programmable read only memory (PROM) or an EPROM, and/or a volatile memory such as a DRAM, etc.
Further, any reference to “outputting a message” or “outputting a packet” (or the like) can be implemented based on creating the message/packet in the form of a data structure and storing that data structure in a non-transitory tangible memory medium in the disclosed apparatus (e.g., in a transmit buffer). Any reference to “outputting a message” or “outputting a packet” (or the like) also can include electrically transmitting (e.g., via wired electric current or wireless electric field, as appropriate) the message/packet stored in the non-transitory tangible memory medium to another network node via a communications medium (e.g., a wired or wireless link, as appropriate) (optical transmission also can be used, as appropriate). Similarly, any reference to “receiving a message” or “receiving a packet” (or the like) can be implemented based on the disclosed apparatus detecting the electrical (or optical) transmission of the message/packet on the communications medium, and storing the detected transmission as a data structure in a non-transitory tangible memory medium in the disclosed apparatus (e.g., in a receive buffer). Also note that the memory circuit 36 can be implemented dynamically by the processor circuit 34, for example based on memory address assignment and partitioning executed by the processor circuit 34.
Also note that although the segment routing database 26 is illustrated as distinct from the EIGRP route server device 12, the segment routing database 26 also can be implemented within the EIGRP route server device 12 (or a PCE), for example based on storage of the segment routing database 26 within the memory circuit 36 (or attached disk or solid-state memory drive) of the EIGRP route server device 12 (or the PCE).
The operations described with respect to any of the Figures can be implemented as executable code stored on a computer or machine readable non-transitory tangible storage medium (e.g., floppy disk, hard disk, ROM, EEPROM, nonvolatile RAM, CD-ROM, etc.) that are completed based on execution of the code by a processor circuit implemented using one or more integrated circuits; the operations described herein also can be implemented as executable logic that is encoded in one or more non-transitory tangible media for execution (e.g., programmable logic arrays or devices, field programmable gate arrays, programmable array logic, application specific integrated circuits, etc.). Hence, one or more non-transitory tangible media can be encoded with logic for execution by a machine, and when executed by the machine operable for the operations described herein.
In addition, the operations described with respect to any of the Figures can be performed in any suitable order, or at least some of the operations in parallel. Execution of the operations as described herein is by way of illustration only; as such, the operations do not necessarily need to be executed by the machine-based hardware components as described herein; to the contrary, other machine-based hardware components can be used to execute the disclosed operations in any appropriate order, or at least some of the operations in parallel.
Referring to
The processor circuit 34 of each EIGRP router 14 in operation 42 also can detect its neighbors, for example according to EIGRP protocol, and/or another protocol (for example based on exchange of advertisement messages advertising segment identifiers (SIDs). For example, segment identifiers (SIDs) can be assigned to different “executable routing instructions” in the data network 10, where a SID can be executable by one or more of the EIGRP routers 14 for one or more identified service types. Hence, segment routing can be implemented in the data network 10 based on the processor circuit 34 in the EIGRP route server device 12 (or a PCE) generating a service-optimized path 16 for reaching a destination network device (e.g., the EIGRP router “R6” 14), the service-optimized path 16 comprising a sequence of executable segments 76 (identified by respective SIDs) that are executed by one or more of the EIGRP routers 14, where a SID may identify an adjacency SID (for reaching an adjacent EIGRP router 14), a prefix SID (associating the SID with a prescribed Internet Protocol (IP) address prefix), a SID label associated with a particular routing instruction (e.g., providing a guaranteed Quality of Service (QoS), providing a prescribed minimum or maximum bandwidth, ensuring transmission to a destination is below a prescribed maximum delay, etc.).
The processor circuit 34 of each EIGRP router 14 in operation 44 can detect each of the policies and topology parameters obtained in operations 40 and 42 as telemetry information, and generate in operation 46 an EIGRP update message 20 that includes EIGRP information 24 and telemetry information 22, illustrated in
The telemetry information 22 generated by the processor circuit 34 of an EIGRP router 14 in operation 46 can include service-based attributes 48 and topology information 56, also referred to generally as non-EIGRP TLV elements. The service-based attributes 48 can be illustrated in
Hence, the service-based attributes 48 can identify all service-based parameters and/or attributes associated with the EIGRP router 14 enforcing one or more service types or service levels.
The telemetry information 22 also can include segment ID TLVs 56 that can describe topology information for the corresponding EIGRP router 14, including link-state information, Segment Routing-based topology parameters associated with mapping the logical Segment Routing topology to the physical topology identifiable by the EIGRP information 24. Example SID TLVs 56 can include a SID Label TLVs (identifying a specific SID Label) 56a associated with one or more prefix SID TLVs 56b and/or one or more adjacency SID TLVs 56c. As illustrated in
Although not shown in
Hence, the EIGRP update message 20 output by the device interface circuit 32 of the EIGRP router 14 in operation 46 of
The device interface circuit 32 of an EIGRP router (e.g., “R6”) 14 is configured for outputting in operation 46 the generated EIGRP update message 20 to its adjacent (i.e. next-hop) EIGRP router (e.g., “R3” and/or “R5”) 14 via a data link 18, for forwarding and delivery to the EIGRP route server device 12 (deployed, for example, near a summary point such as the EIGRP router “R1” 14). The telemetry information 22 also can be specified in an EIGRP Query message and/or an EIGRP Reply message, as appropriate. As described in further detail below with respect to
Assume with respect to
The processor circuit 34 of the next-hop EIGRP router (e.g., “R3”) 14 can forward the EIGRP update message 20 originated by EIGRP router “R6” to its next-hop neighbor (e.g., “R4”) 14 and generate and output its own EIGRP update message 20 as described previously with respect to operations 40, 42, 44, and 46 of
The telemetry information 22 can be opaque to any EIGRP router that is not configured for parsing or interpreting the telemetry information 22 in a received EIGRP update message 20; hence, a conventional EIGRP router can execute existing EIGRP update processing on the received EIGRP update message 20, while ignoring the telemetry information 22, or simply forward the received telemetry information 22.
As illustrated in
The EIGRP update message 20 sent in operation 46 can be sent directly to the EIGRP route server as a unicast, multicast, or anycast message.
In response to the device interface circuit 32 of the EIGRP route server device 12 receiving the EIGRP update message 20 from the EIGRP router “R1”, the processor circuit 34 of the EIGRP route server device 12 in operation 72 can generate a service-based topology map 28, illustrated in
Hence, the processor circuit 34 of the EIGRP route server device 12 in operation 74 can generate one or more service-optimized paths 16 to an identified destination network device in the data network 10, where the destination network device can be an EIGRP router (e.g., “R6”) 14, a network device (not shown) attached to an EIGRP router device (e.g., “R6”) 14, etc. In particular, each service-optimized path 16 is based on one or more “segments” 76 having a corresponding SID that defines the routing instruction to be performed for one or more identified service types; hence, the processor circuit 34 of the EIGRP route server device 12 in operation 74 can generate a plurality of identified segments 76 for segment routing, each identified segment 76 identifying a corresponding routing instruction to be executed by an identified one or more of the EIGRP routers 14 according to a corresponding identified service type.
The processor circuit 34 of the EIGRP route server device 12 in operation 74 can generate one or more service-optimized paths 16 for an identified service type based on associating in sequence one or more of the identified segments 76 associated with the identified service type. For example, assuming multiple identified segments 76 for each of the service types “Bronze”, “Gold”, and “Platinum” (identifying for example respectively distinct QoS service types), the processor circuit 34 of the EIGRP route server device 12 can generate a service-optimized path 16 for reaching a destination network device attached to the EIGRP router “R6” 14 according to the “Gold” service type based on associating in sequence one or more identified segments 76 associated with the “Gold” service type overlying a physical path in the data network 10 from the EIGRP router “R1” 14 to the EIGRP router “R6” 14. Depending on the availability of different identified segments 76 for different service classes, different service-optimized paths may be established for different service classes to provide service differentiation between different network traffic. Further collection of telemetry information for EIGRP router devices beyond a summary point in the data network 10 can be executed by a PCE or equivalent device.
Hence, in response to the device interface circuit 32 of the EIGRP route server device 12 receiving in operation 80 a request (originated by a requesting network device) for a service-optimized path 16 for reaching a destination network device, the processor circuit 34 of the EIGRP route server device 12 in operation 82 can send one or more service-optimized paths 16 to the requesting network device (e.g., one of the EIGRP routers 14), enabling any EIGRP router 14 to reach a destination network device according to an identified service type based on the service-optimized path 16. As an alternative to operations 80 or 82, the PCE can install one or more of the service-optimized paths 16 in one or more of the EIGRP routers 14, eliminating the necessity of the EIGRP routers 14 sending a request for the path.
According to an example embodiment, telemetry information can be added to EIGRP messages, enabling generation of service-optimized paths in an EIGRP network. Hence, EIGRP networks can implement service optimization, for example based on allocating logical network resources based on service type, such as in a network implementing segment routing. The example embodiments also can be used for optimization of other service-based operations in an EIGRP network, for example implementation of traffic engineering.
Although the example embodiments have been described with respect to an EIGRP network, the example embodiments also can be applicable to data networks deploying other distance vector routing protocols.
While the example embodiments in the present disclosure have been described in connection with what is presently considered to be the best mode for carrying out the subject matter specified in the appended claims, it is to be understood that the example embodiments are only illustrative, and are not to restrict the subject matter specified in the appended claims.
