(VRRPE)

BACKGROUND

In traditional Ethernet networking solutions, in order to implement layer-two isolation and layer-three intercommunication between different client hosts, a method of dividing a virtual local area network (VLAN) in a switch is usually adopted. However, when more users require layer-two isolation from each other, VLAN division will take up a lot of VLAN resources. Meanwhile, in order to implement layer-three intercommunication between clients, it is needed to plan different IP network segments for each VLAN and configure IP addresses of VLAN interfaces. Thus, over division of VLAN will reduce the allocation efficiency of IP addresses.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] Features of the present disclosure are illustrated by way of example and not limited in the following figure(s), in which like numerals indicate like elements, in which:

[0003] Fig. 1 is a schematic diagram illustrating an example network structure in which MAC-Forced Forwarding (MFF) and VRRPE are implemented;

[0004] Fig. 2 is a flowchart illustrating an example method for transmitting messages in VRRPE of the present disclosure.

[0005] Fig. 3 is a schematic diagram illustrating an example structure of a device for transmitting messages in VRRPE of the present disclosure.

[0006] Fig. 4 is a schematic diagram illustrating another example structure of a device for transmitting messages in VRRPE of the present disclosure.

DETAILED DESCRIPTION

[0007] For simplicity and illustrative purposes, the present disclosure is described by referring mainly to examples thereof. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be readily apparent however, that the present disclosure may be practiced without limitation to these specific details. In other instances, some methods and structures have not been described in detail so as not to unnecessarily obscure the present disclosure. Throughout the present disclosure, the terms "a" and "an" are intended to denote at least one of a particular element. As used herein, the term "includes" means includes but not limited to, the term "including" means including but not limited to. The term "based on" means based at least in part on.

[0008] In order to improve the present situation of low allocation efficiency of IP addresses caused by over division of VLAN, MAC-Forced Forwarding (MFF) can be used to implement layer-two isolation and layer-three intercommunication between client hosts in the same broadcast domain.

[0009] Virtual Router Redundancy Protocol (VRRP) is a protocol that provides redundancy to routers within a LAN in which a group of routers which can perform gateway functions is added to a backup group to form a virtual router. An election mechanism of VRRP is used to decide which router performs traffic forwarding task. The elected router is the 'main device' of the group of VRPP routers. The hosts in the LAN only need to configure the virtual router as the default gateway.

[0010] In addition to the virtual gateway redundancy backup function provided by VRRP, VRRP load balancing mode (VRRPE) provides load balancing function. The principle of VRRPE includes: one virtual IP address corresponds to multiple virtual MAC addresses; each router in a VRRP backup group corresponds to a virtual MAC address; using different virtual MAC address responses to address resolution protocol (ARP) requests of client hosts, so that traffic of different hosts can be sent to different routers, and each router in the backup group can forward traffic. In VRRPE, one backup group is formed to implement load sharing between multiple routers in the backup group, thereby reducing or avoiding the problem that backup routers in VRRP backup group are always in idle state, and the utilization rate of network resources is low.

[0011 ] There are some problems when MFF and VRRPE are used together. Fig. 1 is a schematic diagram illustrating an example network structure in which MFF and VRRPE are used. In Fig. 1 , device 130 is a server enabled with Dynamic Host Configuration Protocol (DHCP), device 100 is a device enabled to perform MFF functions (hereinafter referred to as 'an MFF device'); and router 111 and router 112 are VRRPE devices. The device 100 is to reply, in place of a gateway, a gateway MAC address to ARP requests of hosts PC121 , PC122 and PC123. The gateway MAC address is obtained by exchanging ARP messages with the gateway, IPv4 is taken as an example for illustration here. The device 100 only records a MAC address of one gateway. In VRRPE, since the MFF function enables device 100 to reply directly, in place of the gateway, to the ARP requests of the clients, the ARP request messages of PC121 , PC122 or PC123 will not be sent to the router 111 or the router 112. As such, PC121 , PC122 and PC123 can only obtain one virtual MAC address of the same VRRPE and cannot perform load balancing.

[0012] In examples of the present disclosure, by intercepting an ARP request message sent by the client, modifying the destination IP address of the ARP request message to be the gateway IP address, and forwarding the ARP request message to a main device of the VRRPE device; and intercepting a response message sent by the VRRPE device according to a load balancing algorithm and sending the ARP response message to the client which sends the ARP request message, the message sent by the client can be sent to a specific gateway in a load balancing manner, thereby allowing integration of MFF and VRRPE and simplifying networking requirements.

[0013] The present disclosure provides a method for transmitting messages in VRRPE in a network with MFF. The network includes an MFF device, and a VRRPE device which is used as a gateway. The MFF device is connected with the VRRPE device, and the MFF device is connected with a plurality of clients.

[0014] Referring to Fig. 2, Fig. 2 is a flowchart illustrating an example method for transmitting messages in VRRPE of the present disclosure. The specific blocks are as following:

[0015] Block 201 : the MFF device intercepts an ARP request message sent by a client connected to the MFF device, records information of the ARP request message, modifies a destination IP address of the ARP request message to be the gateway IP address, and forwards the ARP request message to a main device of the VRRPE device.

[0016] The information of the ARP request message recorded in this block includes a source IP address, the destination IP address, a port number and VLAN ID. When recording the information of the ARP request message, the MFF device sets an information aging or expiry time for the recorded information. If a response message of which a destination IP address is the recorded source IP address is not intercepted within the information aging time, then the locally recorded information of corresponding ARP request message is aged or expires.

[0017] The MFF device can obtain the gateway IP address in this block through the following ways:

manually configuring the gateway IP address;

or, obtaining the gateway IP address from the server by using Dynamic Host Configuration Protocol (DHCP).

[0018] Block 202: the MFF device:

(i) intercepts a response message which is sent by the main device of the VRRPE device,

(ii) takes a virtual MAC address assigned by the main device according to a load balancing algorithm as a source MAC address, and

(iii) sends the ARP response message to the client according to the recorded information of the ARP request message, so that the client can transmit messages according to the source MAC address and the source IP address of the received response message.

[0019] In block 202, (iii) includes: modifying the source IP address of the ARP response message to the recorded destination IP address of the ARP request message, and unicasting the ARP response message to the client according to the port number and the VLAN ID in the recorded information of the ARP request message.

[0020] In block 202, after (i) and (ii) and before (iii), the method further includes:

[0021 ] The MFF device searches the destination IP address of the intercepted response message in the locally recorded information of the ARP request message. If the destination IP address of the intercepted response message is found, then the MFF device sends the ARP response message to the client according to the recorded information of the ARP request message and subsequent blocks; otherwise (not found), transparently transmits the ARP response message.

[0022] If the ARP response message intercepted by the MFF device is a response message sent by the VRRPE device in response to the ARP request message forwarded by the MFF device, then the destination IP address of the ARP response message is recorded as the source IP address in the recorded information of the ARP request message. If the destination IP address of the ARP response message is not in the recorded information, then it shows that the ARP response message may be sent by a server, and the ARP response message is forwarded directly.

[0023] In this block, after the MFF device sends the ARP response message to the client according to the recorded information of the ARP request message, the method further includes:

[0024] The MFF device deletes the recorded information of the corresponding ARP request message. When the virtual MAC address is successfully obtained and sent to the client which sends the ARP request message, the recorded information of the ARP request message can be deleted in order to save memory space.

[0025] The MFF device monitors message interaction between the VRRPE devices, to obtain and record a virtual MAC address of each VRRPE device. The MFF device sets an address aging time for the recorded virtual MAC address of each VRRPE device, and when the address aging time is up, corresponding virtual MAC address is aged. Within the address aging time, when the MFF device monitors the recorded virtual MAC address of the VRRPE device, the recorded address aging time of the corresponding MAC address is updated. That is, the virtual MAC address of each VRRPE device is updated in real time. If one VRRPE is offline or breaks down, if the MFF device does not monitor message interaction between the VRRPE device and other VRRPE devices any more within the set address aging time, then the recorded virtual MAC address of this VRRPE is aged.

[0026] When the preset time is up, if the MFF device intercepts an ARP request message sent by a client connected to the MFF device, the MFF device assigns the recorded virtual MAC address to the client which sends the ARP request message through the load balancing algorithm based on information of the ARP request message. The MFF device also sends a response message, which takes the assigned virtual MAC address as a source MAC address and takes the obtained destination IP address of the ARP request message as a source IP address, to the client so that the client can transmit messages according to the source MAC address and the source IP address of the received response message.

[0027] In examples of the present disclosure, within the preset time, the MFF device does not fast-reply directly, and forwards the ARP request message to the main device of VRRPE so that the main device of VRRPE assigns the virtual MAC address through a load balancing algorithm. When the preset time is up, the MFF device learns all the virtual MAC addresses assigned by the main device of VRRPE. When intercepting an ARP request message, the MFF device itself assigns an obtained virtual MAC address of the VRRPE device through the load balancing algorithm, so that the message sent by the client later can be sent to a specific VRRPE device in a load balancing manner, so that the VRRPE device can fulfill load balancing purposes without networking limits.

[0028] The MFF device sets an address aging time for the recorded virtual MAC address of each VRRPE device, and when the address aging time is up, the corresponding virtual MAC address is aged. Within the address aging time, when the MFF device monitors the recorded virtual MAC address of the VRRPE device, the recorded address aging time of the corresponding MAC address is updated. In practice, the preset time can be set according to specific applications. When the preset time is up, in the case of a stable network, the MFF device has obtained virtual MAC addresses of all VRRPE devices which participate in load-balancing in the network by monitoring message interaction between the VRRPE devices. At this time, the MFF device assigns the virtual MAC address by running load-balancing in the MFF device itself.

[0029] Example implementation(s) of transmission of messages in VRRPE will be hereinafter described in detail with reference to the accompanying drawings. Taking the network shown in Fig. 1 , in order to implement layer-two isolation and layer-three intercommunication between different clients, if the client 121 needs to access the client 122, the VRRPE device 111 or the VRRPE device 112, the client 121 needs to learn the virtual MAC address of a gateway. In Fig. 1 , it is assumed that the VRRPE device 111 is elected as a main device in VRRPE, the VRRPE device 111 assigns a virtual MAC address MAC111 to itself, and the VRRPE device 111 assigns a virtual MAC address MAC112 to the VRRPE device 112.

[0030] Taking the client 121 accessing the client 122 as an example, it is assumed that the preset time is not reached. The MFF device 100 intercepts an ARP request message sent by the client 121 , and the ARP request message is not permitted to be forwarded directly. The MFF device 100 records information of the ARP request message, and the information of the ARP request message includes: a source IP address, a source MAC address, a destination IP address, a port number and VLAN ID of the message. The source IP address and the source MAC address of the message are addresses of the client 121 ; the destination IP address of the message is an address of the client 122; the port number is a port number of a port through which the MFF device 100 receives the ARP request message.

[0031 ] The MFF device 100 obtains the gateway IP address through manual configuration or through DHCP from the server 130. After intercepting the ARP request message, the MFF device 100 modifies the destination IP address of the ARP request message to the gateway IP address, and forwards the ARP request message to the VRRPE device 111 . The operation of the VRRPE device 111 is the same as the existing implementations. The VRRPE device 111 assigns a virtual MAC address to the client which sends the ARP request message through a load balancing algorithm, and takes the virtual MAC address as a source MAC address of a response message. The MFF device 100 intercepts an ARP response message reaching the MFF device 100 itself and does not directly forward the ARP response message. The MFF device 100 needs to determine whether the destination IP address of the ARP response message is recorded in the locally recorded information of the ARP request message. If the destination IP address of the ARP response message is recorded in the locally recorded information of the ARP request message, the ARP response message is a response message which is sent by the main device of VRRPE in response to the ARP request message sent by the MFF device 100. The MFF device 100 finds the corresponding destination IP address, the corresponding port number and the corresponding VLAN ID in the recorded ARP request message, and sends the ARP response message (which takes the found destination IP address as a source IP address) to the client 121 through a port corresponding to the found port number in a VLAN corresponding to the found VLAN ID. This way, the client 121 can transmit messages according to the source MAC address and the source IP address of the ARP response message later. If the destination IP address of the ARP response message is not recorded in the locally recorded information of the ARP request message, then the ARP response message may be other response message. For example, the ARP response message may be a response message through which the server sends IP address, and so on. In this case, the MFF device 100 does not process the ARP response message and forwards the ARP response message directly.

[0032] Taking the client 121 accessing the client 123 as an example, it is assumed that the preset time is exceeded, then the MFF device 100 obtains virtual MAC addresses MAC111 and MAC112 of various VRRPE devices by monitoring message interaction between the VRRPE device 111 and the VRRPE device 112.

[0033] The MFF device 100 intercepts an ARP request message sent by the client 121 and does not allow the ARP message to be forwarded directly. The MFF device 100 assigns a virtual MAC address to the client 121 which sends the ARP request message through the load balancing algorithm; if the virtual MAC address assigned according to the load balancing algorithm is MAC111 . The MFF device 100 sends a response, which takes MAC111 as a source IP address and takes the destination IP address of the ARP request message, i.e., the IP address of the client 123 as a source IP address, to the client 121 , so that the client 121 can transmit messages according to the source MAC address and the source IP address of the ARP response message later.

[0034] The present disclosure also provides a device which can be applied in MFF network. Referring to Fig. 3, Fig. 3 is a schematic diagram illustrating an example structure of a device for transmitting messages in VRRPE of the present disclosure. The device includes: an intercepting unit 301 , a recording unit 302 and a sending unit 303.

[0035] The intercepting unit 301 is to intercept an address resolution protocol (ARP) request message sent by a client connected to a device in which the intercepting unit 301 is; intercept a response message sent by a main device of the VRRPE and takes a virtual MAC address assigned according to a load balancing algorithm as a source MAC address. [0036] The recording unit 302 is to record information of the ARP request message intercepted by the intercepting unit 301 .

[0037] The sending unit 303 is to modify a destination IP address of the intercepted ARP request message to be an obtained gateway IP address, and send the ARP request message to the main device of the VRRPE device; send the ARP response message intercepted by the intercepting unit 301 to the client according to the information of the ARP request message recorded by the recording unit 302, so that the client can transmit messages according to the source MAC address and the source IP address of the received response message.

[0038] The information of the ARP request message recorded by the recording unit 302 includes: the source IP address, the destination IP address, a port number and VLAN ID.

[0039] The sending unit 303 is further to modify a source IP address of the ARP response message to be the destination IP address of the ARP request message recorded by the recording unit 302, and unicast the ARP response message to the client according to the port number and the VLAN ID in the recorded information of the ARP request message.

[0040] The device further includes a search unit 304.

[0041 ] The search unit 304 is to, when the intercepting unit 301 intercepts the ARP response message, search the destination IP address of the intercepted response message in the information of the ARP request message recorded by the recording unit 302.

[0042] The sending unit 303 is further to, if the search unit 304 finds the destination IP address of the intercepted response message in the information of the ARP request message recorded by the recording unit 302, send the ARP response message to the client according to the recorded information of the ARP request message; otherwise, transparently transmit the ARP response message.

[0043] The recording unit 302 is further to, when the sending unit 303 sends the ARP response message to the client according to the recorded information of the ARP request message, delete the recorded information of corresponding ARP request message.

[0044] The recording unit 302 is further to set an information aging time for the recorded information of the ARP request message; if the intercepting unit 301 does not intercept a response message which takes the recorded source IP address as the destination IP address, age the locally recorded information of corresponding ARP request message.

[0045] The device further includes: a monitoring unit 305 and an allocation unit 306.

[0046] The monitoring unit 305 is to monitor interactive messages between the VRRPE devices to obtain and record a virtual MAC address of each VRRPE device.

[0047] The allocation unit 306 is to, when the preset time is up, if the intercepting unit 301 intercepts the ARP request message sent by the client connected to the intercepting unit 301 , assign the virtual MAC address recorded by the monitoring unit 305 to the client which sends the ARP message according to the information of the ARP request message through the load balancing algorithm.

[0048] The sending unit 303 is further to send the ARP response message which takes the virtual MAC address assigned by the allocation unit 306 as a source MAC address and takes the destination IP address of the ARP request message as a source IP address to the client, so that the client can transmit messages according to the source MAC address and the source IP address of the received response message.

[0049] The device further includes an aging unit 307.

[0050] The aging unit 307 is to set an address aging time for the virtual MAC address of each VRRPE device recorded by the monitoring unit 305; and when the address aging time is up, age the corresponding virtual MAC address.

[0051 ] The monitoring unit 305 is further to, within the address aging time set by the aging unit 307, when the recorded virtual MAC address of the VRRPE device is monitored, update the recorded address aging time of the corresponding virtual MAC address.

[0052] The above units can be integrated or combined into one unit. They can also be arranged differently, such as being further split into a plurality of sub-units.

[0053] Figure 4 is a schematic diagram illustrating an example structure of another device for transmitting message in VRRPE according to the present disclosure. As shown in Fig. 4, the device includes a CPU 401 , a memory 402 and a storage 403. The CPU 401 , the memory 402 and the storage 403 are connected with each other via an internal bus. The memory 402 stores units of machine readable instructions executable by the CPU 401 , including an intercepting unit 404, a sending unit 406, a search unit 407, a monitoring unit 408, an allocation unit 409 and an aging unit 410. The storage 403 stores a recording unit 405. Functions of the intercepting unit 404, the recording unit 405, the sending unit 406, the search unit 407, the monitoring unit 408, the allocation unit 409 and the aging unit 410 are similar with the functions of the intercepting unit 301 , the recording unit 302, the sending unit 303, the search unit 304, the monitoring unit 305, the allocation unit 306 and the aging unit 307 respectively. Functions of the intercepting unit 404, the recording unit 405, the sending unit 406, the search unit 407, the monitoring unit 408, the allocation unit 409 and the aging unit 410 are mainly initiated or directed by the intercepting unit 404, the recording unit 405, the sending unit 406, the search unit 407, the monitoring unit 408, the allocation unit 409 and the aging unit 410. The functions may be implemented with the assistance of other modules, and may involve cooperation of multiple modules, e.g., may utilize processing functions of the CPU 401 , may read information from the storage 403, may relay on the internal bus for data transmission, and etc.

[0054] The methods, units and devices described herein may be implemented by hardware, machine-readable instructions or a combination of hardware and machine-readable instructions. Machine-readable instructions used in the examples disclosed herein may be stored in storage medium readable by multiple processors, such as hard drive, CD-ROM, DVD, compact disk, floppy disk, magnetic tape drive, RAM, ROM or other proper storage device. Or, at least part of the machine-readable instructions may be substituted by specific-purpose hardware, such as custom integrated circuits, gate array, FPGA, PLD and specific-purpose computers and so on.

[0055] A machine-readable storage medium is also provided to store instructions to cause a machine to execute a process as described according to examples herein. Specifically, a system or apparatus having a storage medium that stores machine-readable program codes for implementing functions of any of the above examples and that may cause the system or the apparatus (or CPU or MPU) read and execute the program codes stored in the storage medium.

[0056] In this situation, the program codes read from the storage medium may implement any one of the above examples, thus the program codes and the storage medium storing the program codes are part of the technical scheme.

[0057] The storage medium for providing the program codes may include floppy disk, hard drive, magneto-optical disk, compact disk (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tape drive, Flash card, ROM and so on. The program code may be downloaded from a server computer via a communication network.

[0058] It should be noted that, alternatively to the program codes being executed by a computer, at least part of the operations performed by the program codes may be implemented by an operation system running in a computer following instructions based on the program codes to implement any of the above examples.

[0059] In addition, the program codes implemented from a storage medium are written in a storage in an extension board inserted in the computer or in a storage in an extension unit connected to the computer. In this example, a CPU in the extension board or the extension unit executes at least part of the operations according to the instructions based on the program codes to implement any of the above examples. [0060] Although described specifically throughout the entirety of the instant disclosure, representative examples of the present disclosure have utility over a wide range of applications, and the above discussion is not intended and should not be construed to be limiting, but is offered as an illustrative discussion of aspects of the disclosure.

[0061 ] What has been described and illustrated herein is an example along with some of its variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Many variations are possible within the spirit and scope of the subject matter, which is intended to be defined by the following claims -- and their equivalents -- in which all terms are meant in their broadest reasonable sense unless otherwise indicated.