TW201931828A - Flow table-based data transfer method - Google Patents

Abstract

The present invention relates to a flow table-based data transfer method, comprising: issuing a flow table to a first virtual switch, such that an external interface that corresponds to the first virtual switch is configured to accept an ARP request from an external device; the first virtual switch generating, on the basis of the flow table, a corresponding ARP response of the ARP request; the external interface receiving a data package from the external device; determining whether a destination virtual machine of the data package is a physical machine that corresponds to a first node; if the destination virtual machine is a physical machine corresponding to a second node that is different from the first node, then the first virtual switch forwards the data package to a second virtual switch. According to the method, bi-directional transmission of a data package between each terminal and the external device may be reliably and highly efficiently achieved, and the distributed routing communication solution may function to the greatest extent.

Description

Data transmission method based on flow table

The present invention relates to the technical field of data transmission, and more particularly, to a method for transmitting data based on a flow table.

Router is used to connect multiple logically separated networks. The so-called logical network represents a single network or a subnet. When data is transmitted from one subnet to another, it can be done through the routing function of the router. As shown in Figure 1.

Computer communication under different subnets must be completed through a router. In the network implementation of software SDN, the routing function is implemented through software mechanisms, which can be divided into two forms: centralized routing and decentralized routing. (1) Centralized routing

In a centralized routing mechanism, east-west traffic (traffic between different networks) and north-south traffic (traffic between the internal network and the external network) both pass through the router. The core location of the router makes it a bottleneck in the network. To solve this problem, a decentralized routing mechanism is proposed. (2) Decentralized routing

The decentralized routing mechanism enables a router on each node. For east-west traffic, traffic is passed directly between compute nodes. For north-south traffic, if there is a floating IP, the traffic goes directly to the compute node. If there is no floating IP, it will go to the network node. Decentralized routing still uses centralized network nodes when handling traffic without floating IPs, and is still a centralized routing mode in essence.

In software SDN solutions, the implementation of distributed routing functions is based on flow tables. The following uses the openflow flow table and the virtual switch that executes the flow table as an example to outline the problem of traditional distributed routing based on the openflow flow table. The logic diagram of software SDN north-south traffic communication is shown in Figure 2.

A virtual machine (for example, equivalent to a network terminal) in a network communicates with the external network for data flow through a router. In the software SDN solution, the logical diagram is mapped to a physical structure diagram, as shown in FIG. 3. It can be seen that virtual machines on the same network segment may be distributed under different routers. When the virtual machine communicates with the external network, when the data packet goes to the virtual switch, the virtual switch will convert the source IP address of the data packet into the only floating IP corresponding to the virtual machine. For example, when v1 communicates with the external network, the source IP address of the data packet coming out of v1 is still the IP address of v1, that is, 10.0.0.1. After the data packet arrives on the virtual switch, the virtual switch The destination IP address determines that this is a data packet that v1 communicates with the external network. At this time, a corresponding flow table in the virtual switch will convert the source IP address field of the packet, converting 10.0.0.1 to 172.16. .1.1, which is the floating IP of v1. Then for the external network, the IP address of v1 also becomes 172.16.1.1.

Because there is a one-to-one correspondence between the floating IP and the virtual machine, the external network can find the location of v1 through the floating IP when returning packets, and then return the returned packet to v1. However, if v1 does not have a floating IP, the data it actively sends to the publishing network can be sent to the other party, but the return packet of the other party cannot be sent to v1, because the data packet of v1 is based on its intranet address 10.0.0.1 The source IP address is not recognized by the external network. Therefore, you can only use the external network to configure static routing to direct backhaul traffic to the external interface, and then send it to the platform through the interface.

However, in the existing distributed routing architecture design, the external interface may not even have the function of receiving external network data. As shown in Figure 3, the interface between the router and the external network is actually distributed on each node when it is mapped into the physical architecture, that is, each node will have an external interface with an IP address of 172.16.1.100. Therefore, it is still difficult to accurately return external data packets to the corresponding local virtual machines (V1-V6) without floating IPs via the nodes (nodes 1, 2) and then through the subnets (Net1, Net2).

An object of the present invention is to provide a flow table-based data transmission method, which enables bidirectional transmission of data packets even when a floating IP is not applied.

To achieve the above objective, the present invention provides a technical solution as follows:

A flow table-based data transmission method is used to provide a data packet to one of a plurality of network nodes, wherein each node is respectively deployed with a physical machine, and the physical machine is configured with a virtual switch and at least one virtual machine. The method includes routing: a) sending a flow table to the first virtual switch, so that an external interface corresponding to the first virtual switch is configured to receive an ARP request from an external device; wherein the first virtual switch is located at The physical machine corresponding to the first node; b) the first virtual switch generates a corresponding ARP response to the ARP request based on the flow table; c) the external interface receives a data packet from an external device; wherein the data packet is received by the external device Provided after the ARP response; d) determining whether the destination virtual machine of the data packet is on the physical machine corresponding to the first node; and e) if the destination virtual machine is on a physical machine corresponding to the second node different from the first node, the first A virtual switch forwards the data packet to the second virtual switch; wherein the second virtual switch is located at the object corresponding to the second node. Management.

Preferably, the flow table is generated by an SDN controller.

Preferably, the ARP response includes at least the MAC address of the physical machine corresponding to the first virtual switch.

Preferably, in step e), the SDN controller is used to obtain the IP address of the physical machine where the second virtual switch is located, and the data packet is forwarded to the second virtual switch using a tunnel technology.

Preferably, the destination virtual machine is not provided with a floating IP.

The invention further provides a physical machine for receiving data packets, which is deployed at a network node, wherein the physical machine is configured with a virtual switch and at least one virtual machine, the virtual machine is routed by the virtual switch, and the virtual switch is configured based on a flow table to : Receiving an ARP request from an external device through an external interface, and generating a corresponding ARP response to the ARP request; receiving a packet from the external device through an external interface; wherein the packet is provided by the external device after receiving the ARP response; confirm Whether the destination virtual machine of the data packet is on the physical machine corresponding to the first node; wherein the first node is the current network node; and if it is determined that the destination virtual machine is on the physical machine corresponding to the second node, the data packet is forwarded to the A virtual switch in the physical machine corresponding to the two nodes; wherein the second node is a network node different from the first node.

Preferably, the physical machine is coupled to the SDN controller and obtains a flow table from the SDN controller.

The flow table-based data transmission method provided by the embodiments of the present invention can reliably and efficiently implement data packets between each virtual machine and an external device in the case that each network node or a virtual machine therein does not have a floating IP. Between two-way. This method enables the distributed routing communication scheme to maximize its effectiveness and overcome the traffic bottleneck problem that may exist in centralized routing and distributed routing in the prior art. The physical machine provided by the present invention can realize bidirectional transmission of data packets without a virtual machine having a floating IP, thereby promoting the maximum efficiency of the distributed routing communication scheme.

Specific details are set forth in the following description in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention can be implemented without these specific details. In the present invention, specific digital references may be made, such as "first element", "second device", and the like. However, specific numerical references should not be understood as having to obey their literal order, but should be understood as different from "first element" and "second element".

The specific details provided by the present invention are merely exemplary, and the specific details may vary, but still fall within the spirit and scope of the present invention. The term "coupled" is defined to mean directly connected to an element or indirectly connected to an element via another element.

Preferred embodiments of the method, system, and device suitable for implementing the present invention are described below with reference to the drawings. Although the embodiments are described for a single combination of elements, it should be understood that the invention includes all possible combinations of the disclosed elements. Therefore, if one embodiment includes elements A, B, and C and the second embodiment includes elements B and D, the invention should also be considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.

As shown in FIG. 4, a first embodiment of the present invention provides a data transmission method, which is implemented based on a flow table, and specifically includes the following steps.

Step S10: Deliver the flow table to the first virtual switch, so that the external interface corresponding to the first virtual switch is configured to receive an ARP request from an external device.

The first virtual switch is located on a physical machine corresponding to the first node, and the first node may be any one of multiple network nodes. Throughout this application, a network is a specific network defined in accordance with SDN technology. It includes multiple network nodes. Each node can be deployed with a physical machine. A virtual switch and at least one virtual machine are configured in the physical machine. Machines, each virtual machine is routed by a virtual switch in the same physical machine. In other words, the communication between each virtual machine and the external network is realized via a virtual switch. It should be understood that there may be one or more subnets under the network, and the network nodes are connected under the subnet.

According to the embodiment of the present invention, each virtual machine in each network node and / or its corresponding physical machine may not have a floating IP, and two-way communication between the virtual machine and an external device on the network may still be achieved. Specific instructions.

By sending the openflow flow table to the first virtual switch, the openflow flow table can be configured and applied to the first node, so that the external interface corresponding to the first virtual switch is configured to receive ARP (Address Resolution Protocol) from an external device. ) Request, and further, it is possible to generate a response to the ARP request (explained in step S11).

As an example, the flow table is generated by the SDN controller connected to the current network, and is delivered by the SDN controller to all or part of the network nodes in the current network. By sending to the corresponding network node, the flow table will be able to achieve the functionality of the corresponding network node, especially if the network node or its subordinate virtual machine does not have a floating IP, it can still efficiently implement the data packet Two-way transmission between virtual machines and devices external to the network.

In the distributed routing mode, the external interface is distributed on each network node in the network, that is, each virtual switch is provided with an external interface, so in the implementation, a full-volume delivery (flow table) method can be used, that is, each Each network node obtains the flow table, so that the current network as a node cluster has a highly distributed and highly available routing architecture. Alternatively, a certain optimization strategy may be adopted, for example, the flow table used for ARP response is configured to be delivered only to the network node to which the network terminal of the current tenant belongs, or several networks are selected using other strategies The node sends the flow table, which can more quickly receive the external traffic and locate the network terminal. Moreover, the flow table contains less content and is easier to maintain.

The flow table integrates the network configuration information of the current network levels (including subnets) in its entries, so that specific rules can be followed when data is forwarded (communication with the external network), and it can even define more complex and more Rich rules. Specifically, the matching field of the flow table can be used for matching with the data packet received by the virtual switch, which covers the network configuration information of the second to fourth layers in the ISO network model. The action field of the flow table is used to indicate how the virtual switch should handle when it receives a matching packet. The action field can define multiple sets of actions. The flow meter may also include a calculator for counting information about the amount of data flow.

According to a preferred embodiment of the present invention, after the flow table is first issued, the flow table may also be modified according to actual conditions or applications. For example, you can modify the Table value and priority order of the flow table, or change the steps of performing actions in the openflow flow table, or simplify the steps in the flow table (such as without going through the Layer 3 forwarding step), and directly perform port forwarding operations.

Step S11: The first virtual switch generates a corresponding ARP response to the ARP request based on the flow table.

It should be understood that for the physical machine corresponding to each network node, a virtual switch can obtain a flow table and configure itself using the flow table, and then the virtual switch generates a corresponding ARP response to the ARP request, and each ARP response is The content is different. Specifically, by receiving the ARP response, the external device of the network should be able to distinguish at least each physical machine and determine its location in the network, so as to facilitate the subsequent sending of data packets.

In order to implement the decentralized architecture of network routing, the flow table is also issued to other network nodes in the current network (specifically, to the corresponding virtual switches), and the physical machines corresponding to these other network nodes An ARP response packet is sent back and forth through the virtual switch, which contains the MAC address of the physical machine, so that external devices that obtain the MAC address can accurately identify the physical machine.

As an example, the flow table can be designed as follows (only a part of the flow table content is shown):

The main function of the above flow table is to construct a response packet for the ARP request for the external interface, and the external interface sends the response packet back to the ARP requester (network external device). After the requester receives the ARP reply packet, it can further send the data packet to be transmitted to the external interface. It can be understood that the above flow table only shows a part of the actual flow table as an example. In order to realize the complete functionality of the virtual switch and / or virtual machine, the actual flow table will be more complicated. In practical applications, various improvements can be made to the flow table format, such as omitting and / or combining the actions contained in the action domain, limiting the number of executions of each action, and the like.

In this step, the role of the ARP request is to obtain the MAC address of the data sending destination. Each ARP response includes at least the MAC address of the corresponding physical machine of the corresponding network node that is ready to receive the data packet to be transmitted. It should be understood that the ARP request and the ARP response are only preparations before sending the data packet, and the two do not involve the data packet to be transmitted.

Step S12: The external interface receives a data packet from an external device.

In this step, specifically, after the external device obtains the ARP response, it can know the MAC address of the physical machine corresponding to each network node that is preparing to receive the data packet. As for the first node and its corresponding first virtual switch, after the external device receives the ARP response from the first virtual switch, the data packet will be sent to the external interface of the first virtual switch. After the external interface receives the data packet, it can be directly delivered to any virtual machine under the first node, or forwarded, depending on the location of the destination terminal.

In step S13, it is determined whether the destination virtual machine of the data package is a physical machine corresponding to the first node.

Specifically, step S13 is performed by the first virtual switch corresponding to the first node. The virtual switch can directly learn its destination terminal (destination virtual machine) from the data packet, and then determine the network based on the flow table issued by the SDN controller. Whether the destination terminal of the data packet sent by the network device is in a physical machine corresponding to the first node.

If the destination terminal of the data packet is on the physical machine corresponding to the first node, the data packet can be directly delivered to the destination terminal by the first virtual switch. In this case, the completeness of the data packet can be achieved in the most efficient way. Communication, but often this situation is uncertain and random.

As an example, the flow table can be in the following format (showing a part of the flow table):

Step S14: If the destination terminal (destination virtual machine) is on a physical machine corresponding to a second node different from the first node, forward the data packet to the second virtual switch.

The second virtual switch is located on a physical machine corresponding to the second node, and corresponds to the second node.

As a more general case, when the destination terminal is not located on the physical machine corresponding to the first node, but is located on the physical machine corresponding to the second node, the physical machine corresponding to the second node can be obtained based on the flow table or using an SDN controller. IP address, and then use tunnel technology, such as Point to Point Tunneling Protocol (PPTP), to forward the data packet from the first node (specifically, the first virtual switch) to the second node (specifically Ground, the second virtual switch).

As an example, the flow table format in this case is as follows (showing a part of the flow table):

After step S14, the following steps can also be performed: the second virtual switch directly delivers the data packet to the destination virtual machine (because the destination virtual machine is located on the physical machine corresponding to the second node and routed by the second virtual switch), The destination virtual machine finally obtains the data package from the external device.

When the data packet arrives at the second node to be delivered to the destination virtual machine, the example flow table can use the following format:

The flow table-based data transmission method provided by the first embodiment described above uses SDN technology to define the network and uses the flow table to configure the network. In the case where each network node or each virtual machine does not have a floating IP, The two-way transmission of data packets between the virtual machine and the external device can still be achieved reliably and efficiently.

In addition, the above method can overcome the traffic bottleneck problem that may exist in centralized routing and decentralized routing in the prior art, so that the communication scheme of decentralized routing can maximize its effectiveness.

A second embodiment of the present invention provides a physical machine that is deployed at one or more network nodes in a network. The physical machine is configured with a virtual switch and multiple virtual machines, and each virtual machine is routed by a corresponding virtual switch. .

The virtual switch is configured based on the flow table and performs the following operations: (1) receiving an ARP request from an external device through an external interface, and then generating a corresponding ARP response to the ARP request. 2. Receive data packets from external devices through an external interface. The data packet is provided by the external device after receiving the ARP response. (3) Determine whether the destination virtual machine of the data package is the physical machine corresponding to the first node. The first node is a current network node. 24. If it is determined that the destination virtual machine is on the physical machine corresponding to the second node, the data packet is forwarded to the virtual switch on the physical machine corresponding to the second node. For example, the second node is another network node different from the first node.

Specifically, the SDN controller can first network, and can also generate a flow table for configuring each network node in the network, including but not limited to the configuration of a physical machine, a virtual switch, and a virtual machine. The SDN controller can further provide a flow table change unit, so that the designer can change the flow table and redistribute the modified flow table to the virtual switch corresponding to the current network.

According to the flow table, the external interface of the corresponding virtual switch (first virtual switch) of the first node receives the ARP request from the external device.

According to the flow table, the first virtual switch generates a corresponding ARP response to the ARP request, encapsulates the ARP response into a response packet and sends it back to the external device. The ARP response includes the MAC address of the physical machine where the first virtual switch is located.

According to the flow table, the first virtual switch receives a data packet from an external device through its external interface.

According to the flow table, the first virtual switch can determine whether the destination terminal (destination virtual machine) of the data packet is on the physical machine corresponding to the first node.

When the destination terminal is on the physical machine corresponding to the second node (not the first node), according to the flow table, the first virtual switch can forward the data packet to the second virtual switch. This can be achieved through the point-to-point channel communication protocol. The second virtual switch delivers the data packet directly to the destination virtual machine. The second virtual switch is a virtual switch in a physical machine corresponding to the second node, and provides a route to a destination virtual machine.

The virtual switch in the physical machine is configured based on the flow table, so that the physical machine has the following beneficial effects: The physical machine can realize the two-way transfer of data packets between the virtual machine and the external device regardless of whether the virtual machine under the virtual machine has a floating IP. , Which in turn helps the implementation of distributed routing to the maximum extent.

As shown in FIG. 5, a third embodiment of the present invention provides a flow table-based data transmission system for transmitting data packets between multiple network nodes, where each network node is deployed with the second embodiment described above. The disclosed physical machines can be configured using a flow table issued by the SDN controller, so that the virtual switch set therein can receive ARP requests from external devices and generate corresponding ARP responses. After receiving the ARP response, the external device can send the data packet to the desired destination terminal.

Specifically, the first node 11 is provided with a first virtual switch 110, and the second node 12 is provided with a second virtual switch 120. The first and second virtual switches 110 and 120 respectively provide virtual machines V1, V2, V3, and virtual machines. Routing of machines V4, V5, V6.

After using a flow table to configure a virtual switch set in a physical machine, this data transfer system can facilitate bidirectional transmission of data packets between virtual machines and external devices, regardless of whether these virtual machines have floating IPs.

As an example, if the destination terminal of the data package 1 is directed to the virtual machine V1 in the first node 11, the first virtual switch 110 can directly deliver the data package 1 to the virtual machine V1; if the destination terminal of the data package is directed to the second node 12 For the virtual machine V5, the first virtual switch 110 forwards the data packet to the second virtual switch 120 through a tunnel technology, and the second virtual switch 120 delivers the data packet to the virtual machine V5.

In some embodiments of the present invention, at least a part of the above-mentioned system may be implemented using a group of decentralized computing devices connected to a communication network, or based on a "cloud". In such a system, multiple computing devices operate together to provide services by using their shared resources.

"Cloud" -based implementations can provide one or more advantages, including: openness, flexibility and scalability, central management, reliability, scalability, optimization of computing resources, aggregation and analysis across multiple The ability of users' information, connectivity across multiple geographic areas, and the ability to use multiple mobile or data network operators for network connectivity.

According to another embodiment of the present invention, a computer storage medium is provided on which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, the method in the first embodiment described above will be implemented.

According to another embodiment of the present invention, a computer program is provided, which includes a batch of computer-executable instructions. When these computer-executable instructions are executed by a processor, each step in the method in the first embodiment is performed in an orderly manner.

The above description is only directed to the preferred embodiments of the present invention, and is not intended to limit the protection scope of the present invention. Those skilled in the art may make various modified designs without departing from the idea of the present invention and the accompanying claims.

Net1‧‧‧ Subnet

Net2‧‧‧ Subnet

S10‧‧‧step

S11‧‧‧step

S12‧‧‧step

S13‧‧‧step

S14‧‧‧step

V1‧‧‧ Virtual Machine

V2‧‧‧ Virtual Machine

V3‧‧‧ Virtual Machine

V4‧‧‧ Virtual Machine

V5‧‧‧ Virtual Machine

V6‧‧‧Virtual Machine

Figure 1 shows a schematic diagram of the network topology between a router and different subnets.

Figure 2 shows a logic diagram of software SDN north-south traffic communication.

FIG. 3 is a schematic diagram showing the mapping of the interface between the router and the external network to the physical architecture.

FIG. 4 is a schematic flowchart of a transmission method according to an embodiment of the present invention.

FIG. 5 illustrates a network topology of a data transmission system according to an embodiment of the present invention.

Claims (12)

A flow table-based data transmission method for providing a data packet to one of a plurality of network nodes, wherein each of the nodes is respectively deployed with a physical machine configured with a virtual switch and at least one virtual machine. The virtual machine is routed by the virtual switch, and the method includes: a) sending a flow table to the first virtual switch, so that an external interface corresponding to the first virtual switch is configured to receive an external device ARP request; wherein the first virtual switch is located on the physical machine corresponding to the first node; b), the first virtual switch generates a corresponding ARP response to the ARP request based on the flow table; c) 2. The external interface receives a data packet from the external device; wherein the data packet is provided by the external device after receiving the ARP response; d) determining whether a destination virtual machine of the data packet is located The physical machine corresponding to the first node; and e) if the destination virtual machine is different from the first virtual machine, The physical machine corresponding to the second node of the node, the first virtual switch forwards the data packet to the second virtual switch; wherein the second virtual switch is located in the physical corresponding to the second node machine. The method according to claim 1, wherein the flow table is generated by an SDN controller. The method according to claim 2, wherein the ARP response includes at least a MAC address of the physical machine corresponding to the first virtual switch. The method according to claim 2, wherein in step e), the SDN controller is used to obtain the IP address of the physical machine where the second virtual switch is located, and the tunnel is used to forward the data packet to The second virtual switch. The method according to claim 1, wherein the method further comprises: the second virtual switch delivers the data packet to the destination virtual machine. The method according to any one of claims 1 to 5, wherein the destination virtual machine is not provided with a floating IP. A computer storage medium having computer-executable instructions stored therein is characterized in that, when the computer-executable instructions are executed by a processor, the method according to any one of claims 1 to 6 will be implemented. A computer program includes a batch of computer-executable instructions. When the computer-executable instructions are executed by a processor, the steps of the method according to any one of claims 1 to 6 are performed. A physical machine for receiving data packets is deployed at a network node, wherein the physical machine is configured with a virtual switch and at least one virtual machine, the virtual machine is routed by the virtual switch, and the virtual switch is based on The flow table is configured to: 接收 receive an ARP request from an external device through an external interface, and generate a corresponding ARP response to the ARP request; 接收 receive a data packet from the external device through the external interface; wherein the data packet Provided by the external device after receiving the ARP response; determining whether the destination virtual machine of the data packet is the physical machine corresponding to the first node; wherein the first node is the current network node And if it is determined that the destination virtual machine is in the physical machine corresponding to the second node, forwarding the data packet to the virtual switch in the physical machine corresponding to the second node; The second node is a network node different from the first node. The physical machine according to claim 9, wherein the physical machine is coupled to an SDN controller and obtains the flow table from the SDN controller. A flow table-based data transmission system is used to transmit data packets between multiple network nodes, and is characterized in that each of the network nodes is deployed with the physical machine according to claim 9 or 10. The system according to claim 11, wherein the system is deployed based on cloud computing.