WO2013078814A1

WO2013078814A1 - Ip address allocation method and device

Info

Publication number: WO2013078814A1
Application number: PCT/CN2012/074195
Authority: WO
Inventors: 张玉莹
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-12-01
Filing date: 2012-04-17
Publication date: 2013-06-06
Also published as: CN102413203A

Abstract

Disclosed are an IP address allocation method and device. The method comprises: after a dynamic host configuration protocol (DHCP) relay receives a first DHCP discovery message, determining whether to acquire Internet Protocol (IP) addresses from a DHCP server; if yes, acquiring multiple IP addresses from the DHCP server and storing the IP addresses; and selecting an IP address from the acquired IP addresses, and allocating the IP address to a client host that transmits the first DHCP detection message. Through the present invention, the network traffic between the DHCP relay and DHCP server in a DHCP network is reduced, and meanwhile, the requirement for the processing capacity of the DHCP server is lowered.

Description

TECHNICAL FIELD The present invention relates to the field of communications, and in particular to a method and an apparatus for allocating an IP address. A Dynamic Host Configuration Protocol (DHCP) is a dynamic configuration protocol that allocates Internet Protocol (IP) addresses and other network parameters to the host.

The DHCP protocol adopts the client host-server (CLIENT-SERVER) mechanism, and the entire configuration process is automatically implemented. All configuration information is centrally controlled by the DHCP server (DHCP Server). By configuring the IP address to use the lease, you can achieve the IP address reuse effect. Because by default, the router does not send received broadcast packets from one subnet to another. When the DHCP server and the client host are not in the same subnet, the router acting as the default gateway of the client host must send the broadcast packet to the subnet where the DHCP server is located. This function is called DHCP Relay. The DHCP Relay implements transparent interaction between the DHCP client (DHCP Client) and the DHCP server (DHCP Server). Currently, a DHCP relay network generally adopts a topology scheme as shown in FIG. 1. The DHCP client host communicates with the DHCP relay layer through a Layer 2 transparent transmission network. The DHCP relay agent and the DHCP server implement Layer 3 routing. The DHCP packets need to be re-packaged when they pass through the DHCP relay agent. In the DHCP Relay network, whenever a DHCP client host goes online, the DHCP Relay and the DHCP Server complete a DHCP process. 2 is a flow chart of DHCP packet exchange of a client host according to the related art. As shown in FIG. 2, a DHCP client host needs to complete the network parameter acquisition through two exchanges, complete the renewal process through one interaction, and complete the transfer through one pass. Release process. When a large number of DHCP client hosts come online, the number of packets between the DHCP relay agent and the DHCP server will be very large, occupy a large amount of bandwidth, increase unnecessary network traffic, and bring insecure factors to the network. Document processing capabilities are also a big challenge. SUMMARY OF THE INVENTION In the related art, in a DHCP relay network, whenever a DHCP client host goes online, the DHCP Relay needs to complete a DHCP process with the DHCP server, thereby increasing the network traffic between the DHCP Relay and the DHCP Server. The invention provides a method and an apparatus for allocating an IP address to at least solve the above problems. According to an embodiment of the present invention, a method for allocating an IP address is provided, including: after receiving a first dynamic host configuration protocol DHCP discovery message, the DHCP relay determines whether it is necessary to obtain a network protocol IP address from a DHCP server; If the result is yes, the DHCP relay acquires and stores a plurality of IP addresses from the DHCP server; and selects one of the obtained multiple IP addresses to be allocated to send the first DHCP discovery message. Client host. Preferably, in the case that the determining result is no, the method further includes: selecting an IP address from the locally stored IP addresses and assigning the IP address to the client host. Preferably, determining whether to obtain the network protocol IP address from the DHCP server comprises: determining whether the DHCP relay stores an IP address that is not allocated to the client host. Preferably, if the determination result is yes, acquiring the plurality of IP addresses from the DHCP server includes: sending a second DHCP discovery message to the DHCP server; obtaining a request from the DHCP response message sent by the DHCP server to obtain the Multiple IP addresses. Preferably, after obtaining the request to acquire the multiple IP addresses from the DHCP response message sent by the DHCP server, the method further includes: sending, to the DHCP server, a DHCP request message that carries the multiple IP addresses; When the plurality of IP addresses are consistent with the IP address sent by the DHCP, the DHCP acknowledgement message sent by the DHCP server is received. Preferably, after receiving the DHCP confirmation message sent by the DHCP server, the method further includes: establishing a client host information table, where the client host information table is set to record a correspondence between the client host and an IP address allocated for the client host. After receiving the leaving message sent by the client host, releasing the IP address assigned to the client host, deleting the information of the client host in the client host information table; determining that the DHCP server is the DHCP relay After the allocated time of the plurality of IP addresses reaches the first preset lease period, it is determined whether there is still information of the client host in the client host information table, and if the determination result is no, the DHCP is sent to the DHCP. The server sends a DHCP release message to release the plurality of IP addresses. If the determination result is yes, the plurality of IP addresses are renewed to the DHCP server. Preferably, after selecting one of the obtained multiple IP addresses to be allocated to the client host that sends the first DHCP discovery message, the method further includes: when the second preset lease arrives, determining Receiving a leaving message from the client host, if not, sending a notification to the client host, informing the client host to renew the IP address selected from the obtained plurality of IP addresses, wherein The first preset lease period is greater than the second preset lease period. According to another embodiment of the present invention, an apparatus for allocating an IP address is provided, including: a first determining module, configured to: after receiving the first dynamic host configuration protocol DHCP discovery message, determine whether a network protocol needs to be obtained from a DHCP server An IP address; an obtaining module, configured to acquire and store a plurality of IP addresses from the DHCP server if the determination result is yes; and an allocation module configured to select one IP address allocation from the obtained plurality of IP addresses A client host that sends the first DHCP discovery message. Preferably, the allocating module is further configured to: if the result of the determination is negative, select an IP address from the locally stored IP addresses and assign the IP address to the client host. Preferably, the obtaining module includes: a sending unit, configured to send a second DHCP discovery message to the DHCP server; and an acquiring unit, configured to acquire a request to obtain the multiple IPs from a DHCP response message sent by the DHCP server address. Preferably, the device further includes: a sending module, configured to send a DHCP request message carrying the multiple IP addresses to the DHCP server; and a receiving module, configured to send the multiple IP addresses and the DHCP server If the IP addresses are the same, the DHCP confirmation message sent by the DHCP server is received. Preferably, the device further includes: an establishing module, configured to: after receiving the DHCP acknowledgement message, establish a client host information table, where the client host information table is set to record a client host and an IP address assigned to the client host The release module is configured to release the IP address assigned to the client host after receiving the leaving message sent by the client host, and delete the information of the client host in the client host information table; The setting is to determine that the IP address usage time in the DHCP relay reaches a preset lease period; the second determining module is configured to determine whether there is still information about the client host in the client host information table; the sending module is further configured to If the determination result of the second determining module is negative, sending a DHCP release message to the DHCP server, releasing all locally stored IP addresses; and renewing the module, setting the judgment result in the second determining module In the case of YES, the plurality of IP addresses are renewed to the DHCP server. Through the invention, the DHCP relay can apply for multiple IP addresses to the DHCP server through one packet exchange, and implement batch application of the IP address and network parameters. When the client host goes online, the DHCP relay can assign the IP address obtained from the DHCP server to the client host without having to apply for an IP address to the DHCP server when each client host goes online, thereby reducing the DHCP relay and the DHCP server. Network traffic. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawings: FIG. 1 is a schematic diagram of a network topology of a DHCP relay network according to the related art; FIG. 2 is a flowchart of DHCP packet interaction of a client host according to the related art; FIG. 3 is an IP address according to an embodiment of the present invention. FIG. 4 is a flowchart of a method for processing a DHCP Discover message by a DHCP relay according to a preferred embodiment of the present invention; FIG. 5 is a flowchart of a method for processing a DHCP Discover message by a DHCP server according to a preferred embodiment of the present invention; FIG. 6 is a flowchart of a method for processing a DHCP Offer message by a DHCP relay according to a preferred embodiment of the present invention; FIG. 7 is a flowchart of a method for processing a DHCP Request message by a DHCP server according to a preferred embodiment of the present invention; 8 is a flowchart of a method for processing a DHCP ACK message by a DHCP relay according to a preferred embodiment of the present invention; FIG. 9 is a flowchart of a method for processing a DHCP Release message by a DHCP Relay according to a preferred embodiment of the present invention; A block diagram of a device for allocating an IP address of an embodiment of the invention; FIG. 11 is a block diagram showing the structure of a device for allocating a preferred IP address according to an embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. In the related art, in a DHCP relay network, whenever a DHCP client host goes online, the DHCP Relay needs to complete a DHCP process with the DHCP server, thereby increasing the network traffic between the DHCP Relay and the DHCP Server. The example provides a method and a device for allocating an IP address. In the embodiment of the present invention, the DHCP relay can apply for multiple IP addresses to the DHCP server through a packet exchange, and implement batch application of the IP address and network parameters. When the client host goes online, the DHCP Relay can assign the IP address obtained from the DHCP server to the client host, which reduces the network traffic between the DHCP Relay and the DHCP Server. According to the embodiment of the present invention, a method for allocating an IP address is provided, which may be, but is not limited to, a bulk application for implementing a DHCP client host IP address and network parameters in a DHCP Relay in the DHCP relay network as shown in FIG. 2 . FIG. 3 is a flowchart of a method for allocating an IP address according to an embodiment of the present invention. As shown in FIG. 3, the method may include the following steps (step S302-step S306). Step S302: After receiving the first dynamic host configuration protocol (DHCP) discovery message, the DHCP relay determines whether it is necessary to obtain a network protocol IP address from the DHCP server. Step S304, in a case where the determination result is YES, the DHCP relay acquires and stores a plurality of IP addresses from the DHCP server. Step S306, selecting one of the obtained multiple IP addresses to be assigned to the client host that sends the first DHCP discovery message. After receiving the DHCP discovery message, the method first determines whether it is necessary to obtain an IP address and a corresponding network parameter from the DHCP server, and if the judgment result is yes, obtain multiple IP addresses from the DHCP server, and obtain more from the DHCP server. Select one IP address and corresponding network parameters from the IPs, and assign them to the client host requesting the IP address and corresponding network parameters. At the same time, multiple IP addresses allocated by the DHCP server can be saved, so that when other client hosts request to allocate an IP address and corresponding network parameters, the client host can be directly assigned an IP address and corresponding network parameters from the remaining IP addresses without The DHCP server exchanges packets, which reduces network traffic between the DHCP Relay and the DHCP server and reduces the processing power of the DHCP Server. The above various steps are described below. Currently, in a DHCP relay network, when a client host goes online, the IP address and corresponding network parameters can be obtained through a DHCP process. The client host sends a DHCP discovery message to the DHCP Relay (DHCP Discover After receiving the DHCP discovery message, the DHCP Relay re-encapsulates the received DHCP discovery message and sends a re-encapsulated DHCP discovery message to the DHCP server to request the DHCP server to assign an IP address and corresponding network parameters. After receiving the re-encapsulated DHCP discovery message, the client host is assigned an IP address and corresponding network parameters, and sends a DHCP response message (DHCP OFFER) carrying the assigned IP address and corresponding network parameters to the DHCP Relay; the DHCP Relay receives the DHCP response. After the message, the IP address assigned by the DHCP server and the corresponding network parameters are sent to the client host, so that the client host accesses the network through the assigned IP address and corresponding network parameters. However, when a large number of client hosts are online, the DHCP Relay obtains an IP address and corresponding network parameters for each online client from the DHCP server, so that a large number of packet interactions occur between the DHCP Relay and the DHCP server, thereby occupying the network. Bandwidth, and challenges the processing power of the DHCP Server. In the embodiment of the present invention, the DHCP relay can apply for multiple IP addresses and corresponding network parameters to the DHCP server at one time in order to reduce the packet exchange between the DHCP relay and the DHCP server. . When the client host goes online, the DHCP Relay will assign one of the multiple IP addresses requested by the DHCP server to the client host requesting the IP address and corresponding network parameters. During the above process, the DHCP relay does not need to exchange packets with the DHCP server, which reduces the network traffic between the DHCP relay and the DHCP server and reduces the processing requirements of the DHCP server. In addition, a related authentication mechanism can be adopted between the DHCP Relay and the DHCP Server to improve security performance. When the client host goes online, it sends a DHCP discovery message (that is, the first DHCP discovery message) to the DHCP relay. After receiving the DHCP discovery message sent by the client host, the DHCP relay can determine whether it needs to obtain the IP address and corresponding network parameters from the DHCP server. When obtaining the IP address and corresponding network parameters from the DHCP server, obtain multiple IP addresses and corresponding network parameters from the DHCP server. When you do not need to obtain the IP address and corresponding network parameters from DHCP, select from the IP addresses stored in the DHCP Relay. An IP address is assigned to the client host. You can configure the conditions for the DHCP relay to apply for IP addresses and corresponding network parameters from the DHCP server in batches. The DHCP relay determines whether it needs to obtain an IP address from the DHCP server. For example, after the DHCP relay agent receives the DHCP discovery message from the client host, the DHCP relay determines whether the number of remaining IP addresses in the DHCP relay is less than a preset threshold. When the number of IP addresses is less than the preset threshold, the DHCP relay obtains multiple IP addresses and corresponding network parameters from the DHCP server. When the number of remaining IP addresses in the DHCP relay is greater than the preset threshold, the DHCP relay can directly receive the remaining from the DHCP relay. The IP address is assigned to the client host in the IP address and the corresponding network parameters. Alternatively, after receiving the DHCP discovery message, it may be determined whether an IP address is stored in the DHCP Relay. If the DHCP relay stores an IP address, you can directly select an IP address and corresponding network parameters from the IP addresses stored in the DHCP relay, and assign them to the client host that requests the network parameters. If the DHCP relay does not store the client host, The IP address and the corresponding network parameters, the DHCP relay can obtain multiple IP addresses and corresponding network parameters from the DHCP server. After obtaining multiple IP addresses, the DHCP relay selects an IP address and corresponding network parameters from multiple IP addresses obtained. It is assigned to the client host that sends the DHCP discovery message, and the DHCP Relay can store the acquired multiple IP addresses and network parameters, and when other client hosts go online, they are assigned to other client hosts. Further, after receiving the DHCP discovery message, the DHCP relay may determine whether the DHCP discovery message is received for the first time in the current period, that is, after receiving the DHCP discovery message, determine whether the DHCP relay is The DHCP Receive message is received for the first time after each batch release of the IP address. When the DHCP Relay receives the DHCP Discover message for the first time, the DHCP Relay obtains multiple IP addresses and corresponding network parameters from the DHCP server. When the DHCP Relay is not the first Upon receiving the DHCP discovery message, it can be determined that the DHCP relay has obtained multiple IP addresses from the DHCP server. The DHCP relay can select one IP address and corresponding network parameters from multiple IP addresses stored locally, and assign it to send DHCP discovery. The client host of the message. If the DHCP relay needs to obtain multiple IP addresses from the DHCP server, the DHCP relay can re-encapsulate the received DHCP discovery message and send a re-encapsulated DHCP discovery message (second DHCP discovery message) to the DHCP server to request DHCP Server. The DHCP relay assigns multiple IP addresses and corresponding network parameters to the DHCP relay. The DHCP server assigns an IP address to the DHCP relay according to the actual situation. The IP address and corresponding network parameters can be carried in the DHCP response message and sent to the DHCP relay. The DHCP relay receives the DHCP relay. The DHCP response message sent by the DHCP server, and the multiple IP addresses assigned to it and the corresponding network parameters can be obtained from the DHCP response message. At the same time, the DHCP relay can send the received IP address and the corresponding network parameters to the DHCP server. For example, the IP address and the corresponding network parameters are carried in the DHCP request message (DHCP Request message), and the DHCP server allocates the IP address information. After verifying that the IP address information received by the DHCP Relay is consistent with the IP address information assigned to it, the DHCP Relay sends a DHCP acknowledgment message (DHCP ACK message) to the DHCP Relay. The DHCP Relay receives the DHCP acknowledgment message sent by the DHCP server and stores it. The IP address assigned to it and the corresponding network parameters. In practical applications, the number of assigned IP addresses can be determined by the DHCP Relay or by DHCP.

Server is ok. When the DHCP relay determines the number of IP addresses to be assigned, the DHCP Discovery message sent by the DHCP relay can carry the number of IP addresses to be applied for; the number of IP addresses assigned by the DHCP server is determined. When the amount is exceeded, the DHCP server can determine the number of IP addresses assigned to it according to the DHCP relay. For example, according to the number of client hosts owned by the DHCP relay, the IP address of the DHCP relay and/or the DHCP relay application history, and the DHCP server. The amount of the assigned IP address, etc., determines the number of IP addresses assigned to the DHCP Relay. In a preferred embodiment of the present invention, the DHCP Relay may establish a client host information table for managing the IP address assigned to the client and the corresponding network parameters, and record the IP address and corresponding address of the client host and the client host. Correspondence of network parameters. When the client host is offline, it can send a Leave message to the DHCP Relay. After receiving the Leave message sent by the client host, the DHCP Relay releases the IP address assigned to the client host and deletes the information of the corresponding client host in the client host information table. When other client hosts are online, the IP address can be reassigned to the host requesting the IP address and corresponding network parameters. To increase the utilization of IP addresses, you can set a lease for the assigned IP address. Preferably, the DHCP server can assign a longer lease to the IP address segment. The DHCP Relay assigns a shorter lease to the client host. The user's keep-alive can be implemented, and frequent packet exchange between the DHCP relay and the DHCP server is avoided. When the lease of the IP address is reached, the client can renew the IP address and corresponding network parameters to the DHCP relay. The DHCP Relay can continue to the DHCP server when the long lease period allocated by the DHCP server for the IP address segment arrives. Rent IP address and network parameters. In the embodiment of the present invention, in order to reduce signaling interaction between the DHCP relay and the DHCP server, the DHCP may release multiple IP addresses allocated by the DHCP server for the DHCP relay at one time, for example, when the DHCP relay determines the DHCP server. When the usage time of multiple IP addresses (for example, an IP address segment) reaches the preset lease period (that is, the longer lease period mentioned above), it is determined whether there is still information about the client host in the client host information table. If the result of the determination is negative, a DHCP release message is sent to the DHCP server, and all IP addresses stored locally are released. If the determination result is YES, the DHCP server is renewed to a plurality of IP addresses assigned thereto. In a preferred embodiment of the present invention, the DHCP relay can use the Option field in the DHCP packet to complete the batch application of the IP address and corresponding network parameters between the DHCP Relay and the DHCP server. In the preferred embodiment of the present invention, two custom Option fields of the DHCP protocol may be used, which may be called Option-A and Option-B, respectively. The DHCP Relay can be used to perform client host number allocation planning. For example, if the DHCP relay agent is configured to connect 100 client hosts, the DHCP relay agent will receive the DHCP Discover message from the first DHCP client to re-encapsulate the packet. Client host number planning information: Apply for 100 IP addresses and corresponding network parameters. As shown in Figure 4, after receiving the DHCP Discover message, the DHCP Relay can determine to send DHCP.

Whether the client host of the Discover message is the first client host. If it is the first client host, DHCP Relay When the packet is re-encapsulated, the Option-A option field is inserted. This field carries the total number of user plans. If the client host is not the first client host, determine whether there is any remaining IP address segment requested by the DHCP relay. If so, the DHCP relay performs the DHCP server function to directly assign the IP address and network parameters to the DHCP client host. If there is no remaining IP address in the relay, the client host can be denied access and an alarm print is given. As shown in Figure 5, when the DHCP server receives the DHCP Discover message carrying Option-A, it determines whether the DHCP server identifies Option-A. If the DHCP server can identify Option-A, it can parse the parameter information carried in Option-A. (Request for IP address and the number of corresponding network addresses, DHCP Relay client host planning number, etc.). If the DHCP server can meet the requirements described in Option-A, you can assign 100 IP addresses at a time. You can also encapsulate the relevant network parameters into Option-B and insert the DHCP Offer packets to the DHCP Relay. If there are less than 100 IP addresses remaining in the DHCP Server, special handling is required. For example, the DHCP relay is not assigned an IP address, it is considered to be in an abnormal state, and an alarm is given; or, for each DHCP request, an IP address is assigned and an alarm is given; or according to the remaining IP address in the DHCP server. The number is determined by the number of IP addresses assigned by the DHCP Relay. If the DHCP server does not support the Option-A option, you can directly ignore the Option-A option, perform normal process processing, and do not insert the Option-B option in the response packet. As shown in Figure 6, when the DHCP Relay receives the DHCP Offer packet, it determines whether the DHCP Offer packet carries the Option-B option. If the packet carries the correct Option-B option, the temporary user entry is created and sent to the DHCP server. The DHCP Request message carrying the Option-A option is copied to the Option-A option and encapsulated in the DHCP Request message. If the DHCP Offer packet received by the DHCP Relay does not carry the Option-B option, the normal DHCP packet exchange process is performed. As shown in Figure 7, when the DHCP server receives the DHCP Request message carrying Option-A, it compares the received IP address and the corresponding network parameters with the temporary entries established on the DHCP server. If they are the same, the local user is established. The information is sent and the DHCP ACK packet carrying Option-B is sent for confirmation. If the packets are inconsistent, the user access is denied. If the DHCP Request message does not contain the Option-A option, the DHCP message is a normal DHCP process. As shown in Figure 8, when the DHCP Relay receives the DHCP ACK packet, it determines whether to carry the Option-B option. If it is carried, the DHCP Relay establishes a user information table and sends a DHCP ACK packet to the first client. If the DHCP Offer message does not carry the Option-B option, the normal packet exchange process is performed. When the client in the network initiates the DHCP process to obtain the IP address and the corresponding network parameters, the DHCP relay can directly push the IP address and related parameters to act as a DHCP server without having to send packets between the DHCP relay and the DHCP server. Interaction. When the client host that has obtained the IP and network parameters renews the lease, the packet only needs to be exchanged between the user and the DHCP relay. When the lease of the DHCP relay agent expires, a process of renewing the lease between the DHCP relay agent and the DHCP server is performed. The interaction with the above-mentioned packets is similar. As shown in Figure 9, when the DHCP Relay receives the Leave message, it can determine whether it is the last user. When the user is the last user to leave, the DHCP relay can perform the following two methods: 1) clear local user information; 2) send a DHCP Release message to the DHCP server to release all IP addresses. When the user is not the last user, the DHCP relay does not need to exchange packets with the DHCP server. You only need to clear the user information locally. In the actual application, the DHCP Relay can pre-bind the Media Access Control (MAC) address and IP address of the client host, and only assign an IP address to the bound MAC address to improve security. Sex. The preferred embodiment of the present invention optimizes the interaction of the DHCP message, and overcomes the problem that the DHCP packet exchange data traffic is large in a large network topology, which brings a large burden to the DHCP server, and is fully compatible with the existing protocol standard. , greatly reducing the number of DHCP message interactions and improving security performance to a certain extent. According to an embodiment of the present invention, an IP address allocation apparatus is further provided, which can be located in a DHCP relay to allocate an IP address and corresponding network parameters to a client host in a DHCP network. FIG. 10 is a structural block diagram of an apparatus for allocating an IP address according to an embodiment of the present invention. As shown in FIG. 10, the apparatus may include: a first determining module 10, an obtaining module 20, and an allocating module 30. The first judging module 10 is configured to: after receiving the first DHCP discovery message (that is, the DHCP discovery message sent by the client host), determine whether it is necessary to obtain an IP address from the DHCP server (DHCP server); the acquiring module 20, and the first The determining module 10 is coupled to be configured to acquire and store a plurality of IP addresses from the DHCP server if the determination result is yes; the assigning module 30 is coupled to the obtaining module 20, and is configured to select from the acquired multiple IP addresses. An IP address is assigned to the client host that sent the first DHCP discovery message. To avoid increasing network traffic between the DHCP Relay and the DHCP Server, the DHCP Relay can apply to the DHCP Server for multiple IP addresses and corresponding network parameters at one time. When the client host in the network goes online, the DHCP Relay can assign one of the multiple IP addresses requested from the DHCP server to the client host requesting the IP address and the corresponding network parameters. In this process, the DHCP relay does not need to exchange packets with the DHCP server, which can effectively reduce the network traffic between the DHCP relay and the DHCP server. At the same time, the DHCP does not need to process excessive DHCP packets, thus reducing the processing capacity of the DHCP server. Requirements. When the client host goes online, it can send a DHCP discovery message to the DHCP relay. After the DHCP relay receives the DHCP discovery message sent by the client host, the first determining module 10 can determine whether to obtain the IP address and the corresponding network parameter from the DHCP server. When obtaining the IP address and the corresponding network parameter, the obtaining module 20 may obtain multiple IP addresses and corresponding network parameters from the DHCP server. If the DHCP relay does not need to obtain an IP address and corresponding network parameters from the DHCP server, the allocation module 30 may be locally from the DHCP relay. An IP address is selected from the stored IP addresses and assigned to the client host requesting the IP address and corresponding network parameters. You can configure the conditions for the DHCP relay to apply for IP addresses and corresponding network parameters from the DHCP server in batches. The DHCP relay determines whether to obtain an IP address from the DHCP server based on the preset conditions. For example, after the DHCP discovery message of the client host is received, the first determining module 10 can determine whether the number of remaining IP addresses in the DHCP relay is less than a preset threshold. When the number of remaining IP addresses in the relay is less than a preset threshold, the obtaining module 20 may obtain multiple IP addresses and corresponding network parameters from the DHCP server. When the number of remaining IP addresses in the DHCP relay is greater than a preset threshold, the allocation module 30 The client host can be assigned an IP address and corresponding network parameters from the remaining IP addresses in the DHCP Relay. Alternatively, after receiving the DHCP discovery message, the first determining module 10 may determine whether an IP address is stored in the DHCP relay. If the DHCP relay stores an IP address that can be used by the client host, the distribution module 30 can select an IP address and corresponding network parameter from the IP address stored in the DHCP relay, and assign it to the client host that requests the network parameter; The IP address is not stored, and the obtaining module 20 can obtain multiple IP addresses and corresponding network parameters from the DHCP server. After obtaining multiple IP addresses, the allocation module 30 selects an IP address and corresponding network parameters from the obtained IP addresses, and assigns them to the IP address. The client host that sends the DHCP discovery message, and the DHCP Relay can store the acquired multiple IP addresses and network parameters, and when other client hosts go online, they are assigned to other client hosts. Further, after the DHCP relay receives the DHCP discovery message, the first determining module 10 determines whether the DHCP discovery message is received for the first time to receive the DHCP discovery message, that is, after receiving the DHCP discovery message, whether the DHCP relay is determined. It is the first time that a DHCP discovery message is received. When the DHCP relay receives the DHCP discovery message for the first time, the obtaining module 20 can obtain multiple IP addresses and corresponding network parameters from the DHCP server; when the DHCP relay is not receiving the DHCP for the first time The discovery message can be determined that the DHCP relay has obtained multiple IP addresses from the DHCP server, and the distribution module 30 can select one IP address and corresponding network parameters from the obtained multiple IP addresses, and allocate them to the corresponding client host. When the obtaining module 20 can obtain multiple IP addresses from the DHCP server, the DHCP Relay can re-encapsulate the received DHCP discovery message and send the re-encapsulated DHCP to the DHCP server. The discovery message (referred to as the second DHCP discovery message) requests the DHCP server to allocate multiple IP addresses and corresponding network parameters, and the DHCP server allocates an IP address to the DHCP Relay, and carries the allocated IP and corresponding network parameters in the DHCP response message. Sent to the DHCP Relay; DHCP Relay receives the DHCP Server

The DHCP response message, from which the IP address assigned to it and the corresponding network parameters are obtained. Therefore, in a preferred embodiment of the present invention, in order to achieve the above object, the obtaining module 20 may include: a sending unit, configured to send a second DHCP discovery message (ie, a re-encapsulated DHCP discovery message) to the DHCP server; The obtaining unit is configured to obtain a request for acquiring multiple IP addresses and corresponding network parameters from a DHCP response message sent by the DHCP server. At the same time, the DHCP relay can send the received IP address to the DHCP server, and the DHCP authenticates the assigned IP address information. After the verification is passed, for example, after the received IP address information is consistent with the assigned IP address information, the DHCP Relay is sent to the DHCP Relay. A DHCP acknowledgement message is sent, and the DHCP relay receives the DHCP determination message sent by the DHCP server, and stores the assigned IP address and corresponding network parameters. Therefore, in a preferred embodiment of the present invention, as shown in FIG. 11, the foregoing apparatus may further include: a sending module 40, coupled to the acquiring module 20, configured to send a DHCP carrying multiple IP addresses to the DHCP server. The request message 50 is coupled to the sending module 40 and configured to receive the DHCP acknowledgement message sent by the DHCP server when the multiple IP addresses match the IP address sent by the DHCP server. With the preferred embodiment, the reliability of IP address allocation can be improved, and the accuracy of IP address allocation can be ensured. In a preferred embodiment of the present invention, the DHCP relay may establish a client host information table in order to manage the IP address and corresponding network parameters allocated thereto. Therefore, the foregoing apparatus may further include: an establishing module, configured to receive the DHCP After confirming the message, a client host information table is created, wherein the client host information table can record the correspondence between the client host and the IP address assigned to the client host. Through the preferred embodiment, the DHCP Relay can conveniently manage the IP address. When the client host is offline, it can send a Leave message to the DHCP Relay. After receiving the Leave message sent by the client host, the DHCP Relay releases the IP address assigned to the client host and deletes the information of the corresponding client host in the client host information table. When other client hosts are online, the IP address can be assigned here to the host requesting the IP address and the corresponding network parameters. Therefore, the device may further include: a release module configured to: after receiving the leaving message sent by the client host, release the IP address assigned to the client host, and delete the information of the corresponding client host in the client host information table. To increase the utilization of IP addresses, you can set a lease for the assigned IP address. Preferably, the DHCP server can assign a longer lease to the IP address segment. The DHCP Relay assigns a shorter lease to the client host. The user's keep-alive can be implemented, and frequent packet exchange between the DHCP relay and the DHCP server is avoided. When the lease of the IP address is reached, the client host and the DHCP relay can renew the IP address and corresponding Network parameters. After the DHCP relay determines that the IP address usage time in the DHCP relay reaches the preset lease period, it determines whether there is still information about the client host in the client host information table. If the judgment result is no, the DHCP release is sent to the DHCP server. The message releases all IP addresses stored locally, and if the judgment result is yes, the DHCP server is renewed to allocate a plurality of IP addresses assigned thereto. In order to achieve the above object, the foregoing apparatus may further include: a determining module, configured to determine that an IP address usage time in the DHCP relay reaches a preset lease period; and a second determining module, configured to determine whether a client exists in the client host information table The information of the host; if the judgment result is no, the sending module is further configured to send a DHCP release message to the DHCP server to release all the IP addresses stored locally; if the judgment result is yes, the renewal module is set to DHCP. The server renews the leased IP address. From the above description, it can be seen that the following technical effects are implemented in the embodiment of the present invention: The DHCP relay can apply for multiple IP addresses to the DHCP server through one packet exchange, and implement batch application of the IP address and network parameters. When the client host goes online, the DHCP Relay can assign the IP address obtained from the DHCP server to the client host, which reduces the network traffic between the DHCP Relay and the DHCP Server. At the same time, the DHCP relay agent and the DHCP server can adopt the relevant authentication mechanism to improve security. The DHCP relay can pre-bind the MAC address and IP address of the client host, and only assign IP addresses to the bound MAC address to improve security. Sex. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. The steps shown or described are performed, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

1. A method for allocating an IP address, including:

Dynamic host configuration protocol After receiving the first DHCP discovery message, the DHCP relay determines whether it needs to obtain the network protocol IP address from the DHCP server.

In a case where the determination result is yes, the DHCP relay acquires and stores a plurality of IP addresses from the DHCP server;

Selecting one of the obtained multiple IP addresses is assigned to the client host that sends the first DHCP discovery message.

2. The method according to claim 1, wherein, in the case that the determination result is negative, the method further comprises: selecting an IP address from the locally stored IP addresses and assigning to the client host.

3. The method according to claim 1, wherein determining whether to obtain a network protocol IP address from a DHCP server comprises:

It is determined whether the DHCP relay stores an IP address that is not allocated to the client host.

4. The method according to claim 1, wherein, in a case where the determination result is yes, obtaining a plurality of IP addresses from the DHCP server includes:

Sending a second DHCP discovery message to the DHCP server;

Obtaining a request from the DHCP response message sent by the DHCP server to acquire the plurality of IP addresses.

The method according to claim 4, wherein, after obtaining the request for acquiring the plurality of IP addresses from the DHCP response message sent by the DHCP server, the method further includes:

And sending, by the DHCP server, a DHCP request message that carries the multiple IP addresses; and if the multiple IP addresses are consistent with the IP address sent by the DHCP server, receiving a DHCP confirmation message sent by the DHCP server.

The method according to claim 5, wherein, after receiving the DHCP acknowledgement message sent by the DHCP server, the method further includes:

Establishing a client host information table, where the client host information table is set to record a correspondence between the client host and an IP address assigned to the client host; After receiving the leaving message sent by the client host, releasing the IP address assigned to the client host, and deleting the information of the client host in the client host information table;

After determining that the usage time of the multiple IP addresses allocated by the DHCP server for the DHCP relay reaches a first preset lease period, determining whether there is still information about the client host in the client host information table, If the result is no, a DHCP release message is sent to the DHCP server to release the plurality of IP addresses. If the determination result is yes, the plurality of IP addresses are renewed to the DHCP server.

The method according to claim 6, wherein after selecting one of the plurality of acquired IP addresses to be allocated to the client host that sends the first DHCP discovery message, the method further includes: When the second preset lease arrives, it is determined whether a departure message from the client host is received, and if not, a notification is sent to the client host to notify the client host to renew the obtained multiple IPs from the lease. The IP address selected in the address, where the first preset lease period is greater than the second preset lease period.

8. A device for allocating an IP address, comprising:

The first determining module is configured to: after receiving the first dynamic host configuration protocol DHCP discovery message, determine whether the network protocol IP address needs to be obtained from the DHCP server;

Obtaining a module, configured to acquire and store a plurality of IP addresses from the DHCP server if the determination result is yes;

And an allocating module, configured to select one of the obtained multiple IP addresses to be assigned to the client host that sends the first DHCP discovery message.

9. The apparatus according to claim 8, wherein the allocating module is further configured to: when the determination result is negative, select an IP address from the locally stored IP addresses and assign the IP address to the client host.

The device according to claim 8, wherein the obtaining module comprises:

And a sending unit, configured to send a second DHCP discovery message to the DHCP server, where the acquiring unit is configured to acquire the multiple IP addresses from the DHCP response message sent by the DHCP server.

The device according to claim 10, wherein the device further comprises:

a sending module, configured to send, to the DHCP server, a DHCP request message that carries the multiple IP addresses; The receiving module is configured to receive a DHCP acknowledgement message sent by the DHCP server if the multiple IP addresses are consistent with the IP address sent by the DHCP server.

12. The device according to claim 11, wherein the device further comprises:

The establishing module is configured to: after receiving the DHCP confirmation message, establish a client host information table, where the client host information table is set to record a correspondence between the client host and an IP address assigned to the client host;

The release module is configured to: after receiving the leaving message sent by the client host, release the IP address assigned to the client host, and delete the information of the client host in the client host information table;

The determining module is configured to determine that the IP address usage time in the DHCP relay reaches a preset lease period; the second determining module is configured to determine whether there is still information about the client host in the client host information table;

The sending module is further configured to: when the determination result of the second determining module is negative, send a DHCP release message to the DHCP server, release all locally stored IP addresses; and renew the renting module, set to When the determination result of the second determination module is YES, the plurality of IP addresses are renewed to the DHCP server.