CN102255814A - Method, device and system for selecting transfer path - Google Patents

Abstract

The embodiment of the invention discloses a method, device and system for selecting a transmission path. Adopting the technical solution provided by the embodiment of the present invention, by analyzing information such as the client IP address in the DHCP response message, generating an optimal path information table to guide the forwarding of the client data message, the data message transmission path in the prior art can be solved. The authentication path of the access network is inconsistent, and the client cannot access the network.

Description

A method, device and system for selecting transmission path

technical field

The invention relates to the field of network communication, in particular to a method, device and system for selecting a transmission path.

Background technique

There are three roles in the Dynamic Host Configuration Protocol (DHCP for short): DHCP client, DHCP server and DHCP relay. When the DHCP client and the DHCP server are in different subnets, the DHCP relay agent can relay the DHCP protocol packets to the destination DHCP server across network segments, so that the DHCP clients on different networks can share one DHCP server.

Broadband Remote Access Server (BRAS for short) is a new type of access gateway for broadband network applications. It is located at the edge of the backbone network and completes user access, authentication, billing, and control of various broadband access methods , management, and realize the aggregation and forwarding of various services. The BRAS can act as a DHCP server at the same time. After completing the user authentication, it sends a DHCP response message to the DHCP relay agent, which is used to assign an Internet Protocol (Internet Protocol, referred to as IP) address and a Domain Name Server (Domain Name Server, Domain Name Server) to the DHCP client. DNS) and other configuration information, and generate a user forwarding checklist on the BRAS, check the user's source IP, virtual local area network (Virtual Local Area Network, referred to as VLAN) and other information, and prevent counterfeit user traffic from being forwarded from the BRAS device .

If the DHCP relay agent is connected to multiple BRASs at the same time, or there are multiple virtual links between the DHCP relay agent and a BRAS, when the data packet transmission path of the client is inconsistent with the authentication path of the client accessing the network, due to the forwarding check table, The validity check of the data packet of the client fails, causing the client to fail to access the network.

Contents of the invention

Embodiments of the present invention provide a method, device and system for selecting a transmission path to solve the problem in the prior art that the data message transmission path of the client is inconsistent with the authentication path for the client to access the network, and the client cannot access the network.

According to one aspect of the present invention, the present invention provides a method for selecting a transmission path, comprising:

Receiving a Dynamic Host Configuration Protocol DHCP response message, the DHCP response message including the client's Internet Protocol IP address;

Acquire preferred path information according to the DHCP response message, where the preferred path information includes a correspondence between the IP address of the client and the port identifier of the port receiving the DHCP response message;

Recording the preferred route information in the preferred route information table;

receive datagrams;

Query the preferred path information table according to the source IP address of the data message, when the source IP address of the data message is the same as the IP address of an existing preferred path information in the preferred path information table, from The port corresponding to the port identifier in the existing preferred path information forwards the data message.

According to another aspect of the present invention, the present invention provides a device for selecting a transmission path, including a receiver, an acquisition unit, a recording unit, an inquiry unit and a transmitter, wherein:

The receiver is configured to receive a DHCP response message from the server, the DHCP response message includes the client's Internet Protocol IP address; the receiver is also used to receive a data message;

The obtaining unit is configured to obtain preferred path information according to the DHCP response message, the preferred path information including the correspondence between the IP address of the client and the port identifier of the port receiving the DHCP response message;

The recording unit is configured to record the preferred route information in the preferred route information table;

The query unit is configured to query the preferred path information table according to the source IP address of the data message;

The sender is configured to, when the source IP address of the data message is the same as the IP address of an existing preferred path information in the preferred path information table, corresponding to the port identifier from the existing preferred path information The port forwards the data packet.

According to another aspect of the present invention, the present invention provides a system for selecting a transmission path, including a network device and a server, wherein:

The network device is configured to receive a DHCP response message from the server, the DHCP response message includes the IP address of the client, obtains preferred path information according to the DHCP response message, and the preferred path information includes the The IP address of the client and the port identification of the DHCP response message; record the preferred path information in the preferred path information table; the network device is also used to receive data packets, according to the source IP of the data packets address query the preferred path information table, when the source IP address of the data message is the same as the IP address of an existing preferred path information in the preferred path information table, from the port of the existing preferred path information Identify the corresponding port to forward the data packet.

Adopting the technical solution provided by the present invention, by analyzing information such as the client IP address in the DHCP response message, generating an optimal path information table to guide the forwarding of the client data message, the data message transmission path of the client in the prior art can be solved The authentication path for the client to access the network is inconsistent, and the client cannot access the network.

Description of drawings

FIG. 1 is a flow chart of a method for selecting a transmission path provided by an embodiment of the present invention;

Fig. 2 is an information interaction diagram for selecting a transmission path provided by an embodiment of the present invention;

Fig. 3 is another information interaction diagram for selecting a transmission path provided by an embodiment of the present invention;

FIG. 4 is a flow chart of another method for selecting a transmission path provided by an embodiment of the present invention;

Fig. 5 is a block diagram of a device for selecting a transmission path provided by an embodiment of the present invention;

Fig. 6 is a block diagram of a system for selecting a transmission path provided by an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

Embodiments of the present invention provide a method, device and system for selecting a transmission path. The method includes: receiving a DHCP response message, the DHCP response message including the IP address of the client; obtaining preferred path information according to the DHCP response message, the preferred path information including the client's IP address and Receive the corresponding relationship of the port identification of the port of the DHCP response message; record the preferred path information in the preferred path information table; receive the data message; query the preferred path information according to the source IP address of the data message table, when the source IP address of the data message is the same as the IP address of an existing preferred path information in the preferred path information table, forward the datagram. Adopt the technical scheme that the embodiment of the present invention provides, by analyzing information such as client IP address in the DHCP response message, generate preferred path information table, guide the forwarding of client data message, guarantee the data message transmission path of client and client The authentication path for accessing the network is the same, enabling the client to access the network normally.

Referring to FIG. 1 , it is a flow chart of a method for selecting a transmission path provided by an embodiment of the present invention, and the method includes:

101: The network device receives the DHCP request message from the client, and forwards the DHCP request message to the server; the server assigns an IP address to the client, and responds to a DHCP response message; the network device receives the A DHCP response message, where the DHCP response message includes the IP address of the client.

The network device includes a router with a DHCP relay function.

The server includes a router with a DHCP server function, such as a BRAS.

102: The network device acquires preferred path information, where the preferred path information includes a correspondence between the IP address of the client and the port identifier of the port receiving the DHCP response message;

The network device can parse the DHCP response message to obtain the IP address of the client.

The port identifier may be a port number; it may also be a port number and a VLAN identifier.

The network device may also acquire the VLAN identifier according to the DHCP response message.

103: The network device records the preferred path information in a preferred path information table.

Optionally, the network device establishes the preferred path information table according to the DHCP response message.

The network device forwards the DHCP response message to the client.

104: The network device receives a data packet;

105: The network device queries the preferred path information table according to the source IP address of the data packet;

106: When the source IP address of the data message is the same as the IP address of an existing preferred path information in the preferred path information table, forward the datagram.

When the source IP address of the data message is different from the IP address of any existing preferred path information in the preferred path information table, the network device forwards the data message according to the routing table.

For example, as shown in FIG. 2 , client A is simultaneously connected to BRAS1 and BRAS2 through a DHCP relay agent, wherein port Port1 of the DHCP relay agent is connected to BRAS1, and port Port2 of the DHCP relay agent is connected to BRAS2.

When client A accesses the network, it sends a DHCP request message to the DHCP server through the DHCP relay agent, requesting to assign an IP address;

After the DHCP relay agent receives the DHCP request message sent by client A, it forwards the DHCP request message sent by client A to BRAS1;

After receiving the DHCP request message, BRAS1 allocates an IP address and configuration information, etc. for client A, and encapsulates them in a DHCP response message and sends them to the DHCP relay agent;

After the DHCP relay agent receives the DHCP response message, it parses the DHCP response message to obtain the IP address IP-A assigned to client A, and records the port number Port1 and IP-A that received the DHCP response message to the preferred path information table; for example, as shown in Table 1:

Table 1 Optimal route information table

IP address The port number ... IP-A Port1

The DHCP relay forwards the DHCP response message to the client A;

Client A receives the DHCP response message, and obtains the IP address IP-A and configuration information, such as DNS, from the DHCP response message.

When client A accesses the network, the source IP address of the data packet sent is IP-A;

After the DHCP relay receives the data message, it preferentially searches the optimal path information table according to the source IP address of the data message, namely IP-A;

When the preferred path information table contains an IP address of IP-A with existing preferred path information, the corresponding port is identified from the port of the existing preferred path information, that is, Port1, and the data message is forwarded. In this way, it is ensured that the transmission path of the data packet of the client is consistent with the authentication path of the client accessing the network.

For another example, as shown in Figure 3, port Port1 of the DHCP relay is connected to BRAS1, and there are virtual link 1 and virtual link 2 between the DHCP relay and BRAS1, wherein virtual link 1 corresponds to VLAN1 (Virtual Local Area Network , virtual local area network, referred to as VLAN), virtual link 1 corresponds to VLAN2.

When client A accesses the network, it sends a DHCP request message to BRAS1 through VLAN1;

After BRAS1 receives the DHCP request message, it allocates an IP address and configuration information for client A, and encapsulates them in a DHCP response message and sends it to the DHCP relay agent;

After the DHCP relay receives the DHCP response message, it parses the DHCP response message to obtain the IP address IP-A assigned to client A, and will receive the port identifier Port1 and VLAN1 of the DHCP response message, and IP-A Record it in the preferred path information table; for example, as shown in Table 2:

Table 2 Optimal route information table

IP address The port number VLAN ID ... IP-A Port1 VLAN1

The DHCP relay forwards the DHCP response message to the client A;

Client A receives the DHCP response message, and obtains the IP address IP-A, configuration information, and so on.

When client A accesses the network, the source IP address of the data packet sent is IP-A;

After the DHCP relay receives the data message, it preferentially inquires the optimal path information table according to IP-A;

When there is an IP address of IP-A in the preferred path information table, the data message is forwarded from the port Port1 and VLAN1 corresponding to the port identifier. In this way, it is ensured that the transmission path of the data packet of the client is consistent with the authentication path of the client accessing the network.

As shown in FIG. 4, it is a flow chart of another method for selecting a transmission path provided by an embodiment of the present invention, and the method includes:

The network device may configure a transmission path selection policy and set a state of the transmission path selection policy.

The network device receives the DHCP request message from the DHCP client, and forwards the DHCP request message to the DHCP server; the DHCP server assigns an IP address for the DHCP client, and responds to the DHCP response message; the network device receives The DHCP response message includes the IP address of the DHCP client.

When the state of the transmission path selection strategy is set to enable Enable, the network device obtains the preferred path information when the DHCP client accesses the network, records the preferred path information in the preferred path information table, and then sends the DHCP The client forwards the DHCP response message; when the state of the transmission path selection policy is set to disable, the network device forwards the DHCP response message to the DHCP client.

The network device receives the data packet.

When the state of the transmission path selection policy is set to Enable, the network device queries the preferred path information table according to the source IP address of the data message, when the source IP address of the data message is the same as When the IP address of an existing preferred path information in the preferred path information table is the same, the data packet is forwarded from the port corresponding to the port identifier in the existing preferred path information; when the source IP address of the data packet is When the address is different from the IP address of any existing preferred path information in the preferred path information table, the network device forwards the data packet according to the routing table. When the state of the transmission path selection policy is set to disable, the network device forwards the data message according to the routing table.

The network device is a DHCP relay.

Referring to FIG. 5 , it is a block diagram of a device for selecting a transmission path provided by an embodiment of the present invention. The device includes a receiver 501, an acquisition unit 502, a recording unit 503, a query unit 504 and a transmitter 505, wherein:

The receiver 501 is configured to receive a DHCP response message from the server, the DHCP response message includes the IP address of the client; the receiver 501 is also used to receive a data message;

The obtaining unit 502 is configured to obtain preferred path information according to the DHCP response message, the preferred path information including the correspondence between the IP address of the client and the port identifier of the port receiving the DHCP response message;

The recording unit 503 is configured to record the preferred route information in the preferred route information table;

The query unit 504 is configured to query the preferred path information table according to the source IP address of the data packet;

The sender 505 is configured to, when the source IP address of the data message is the same as the IP address of an existing preferred path information in the preferred path information table, identify the port from the existing preferred path information The corresponding port forwards the data message.

The device includes a router with a DHCP relay function.

Optionally, the acquiring unit 502 is further configured to acquire the VLAN ID of the client access network.

The port identifier may be a port number; it may also be a port number and a VLAN identifier.

The device may also include:

The establishing unit is configured to establish the preferred route information table before recording the preferred route information in the preferred route information table.

The sender 505 is also configured to forward the DHCP response message to the client.

When the source IP address of the data message is different from the IP address of any existing preferred path information in the preferred path information table, the query unit 504 is further configured to Querying the routing table to obtain a next-hop egress port identifier, and the sender 505 is configured to forward the data packet from a port corresponding to the next-hop egress port identifier.

Optionally, the device also includes:

The policy unit is configured to configure a transmission path selection policy, and set the state of the transmission path selection policy to Enable or Disable.

When the state of the transmission path selection policy is Enable, the acquiring unit 502, the recording unit 503, the querying unit 504 and the transmitter 505 perform the above corresponding operations.

When the state of the transmission path selection policy is disabled, the query unit 504 is used to query the routing table according to the destination address of the data message to obtain the next hop exit port identifier, and the sender 505 is used to Forwarding the data packet from the port corresponding to the next hop egress port identifier.

Referring to FIG. 6 , it is a block diagram of a system for selecting a transmission path provided by an embodiment of the present invention. The system includes a network device 601 and a server 602 . in:

The network device 601 is configured to receive a DHCP response message from the server 602, the DHCP response message includes the IP address of the client, and obtains preferred path information according to the DHCP response message, and the preferred path information Including the IP address of the client and the port identifier of the DHCP response message; recording the preferred path information in the preferred path information table; the network device is also used to receive data packets, according to the data packet The source IP address queries the preferred path information table, and when the source IP address of the data message is the same as the IP address of an existing preferred path information in the preferred route information table, the preferred path information from the existing preferred path information The port corresponding to the port identifier forwards the data packet.

The port identifier may be a port number; it may also be a port number and a VLAN identifier.

The network device 601 is further configured to forward the datagram according to the routing table when the source IP address of the datagram is different from the IP address of any existing preferred path information in the preferred path information table arts.

The network device includes a router with a DHCP relay function.

The server includes a router with a DHCP server function, such as a BRAS.

The network device 601 is further configured to receive a DHCP request message from a client, and forward the DHCP request message to the server 602 .

The server 602 is configured to receive the DHCP request message, assign an IP address to the client, and send the DHCP response message to the network device 601 .

The network device 601 is further configured to forward the DHCP response message to the client.

Adopting the technical solution provided by the embodiment of the present invention, by analyzing information such as the client IP address in the DHCP response message, generating an optimal path information table to guide the forwarding of the client data message, the data message of the client in the prior art can be solved. The transmission path is inconsistent with the authentication path for the client to access the network, and the client cannot access the network.

Those of ordinary skill in the art can understand that all or part of the steps in the method of the above-mentioned embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, and the storage medium can be a ROM /RAM, disk or CD, etc.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention.

Claims (11)

1. A method for selecting a delivery path, comprising: Receiving a Dynamic Host Configuration Protocol DHCP response message, the DHCP response message including the client's Internet Protocol IP address; Acquire preferred path information according to the DHCP response message, where the preferred path information includes a correspondence between the IP address of the client and the port identifier of the port receiving the DHCP response message; Recording the preferred route information in the preferred route information table; receive datagrams; Query the preferred path information table according to the source IP address of the data message, when the source IP address of the data message is the same as the IP address of an existing preferred path information in the preferred path information table, from The port corresponding to the port identifier in the existing preferred path information forwards the data packet. 2. The method according to claim 1, characterized in that the method further comprises: When the source IP address of the data message is different from the IP address of any existing preferred path information in the preferred path information table, the data message is forwarded according to the routing table. 3. method according to claim 2, is characterized in that, before receiving the DHCP response message from server, also comprises: receiving a DHCP request message from the client; Forward the DHCP request message to the server. 4. The method according to any one of claims 1 to 3, wherein, before obtaining the preferred path information according to the DHCP response message, it also includes configuring a local transmission path selection strategy, selecting the transmission path The status of the policy is set to Enable. 5. The method according to any one of claims 1 to 4, wherein the port identifier includes a port number, or The port identifier includes a port number and a VLAN identifier. 6. A device for selecting a transmission path, comprising a receiver, an acquisition unit, a recording unit, an inquiry unit and a transmitter, wherein: The receiver is configured to receive a DHCP response message from the server, the DHCP response message includes the client's Internet Protocol IP address; the receiver is also used to receive a data message; The obtaining unit is configured to obtain preferred path information according to the DHCP response message, the preferred path information including the correspondence between the IP address of the client and the port identifier of the port receiving the DHCP response message; The recording unit is configured to record the preferred route information in the preferred route information table; The query unit is configured to query the preferred path information table according to the source IP address of the data message; The sender is configured to, when the source IP address of the data message is the same as the IP address of an existing preferred path information in the preferred path information table, corresponding to the port identifier from the existing preferred path information The port forwards the data packet. 7. The device according to claim 6, wherein the transmitter is further used for, When the source IP address of the data message is different from the IP address of any existing preferred path information in the preferred path information table, the data message is forwarded according to the routing table. 8. The device according to claim 6, wherein the device further comprises a strategy unit configured to configure a local transmission path selection strategy before obtaining the preferred path information according to the DHCP response message, and to set the The state of the routing selection policy is set to Enable. 9. The device according to claim 6, further comprising an establishment unit, configured to establish the preferred route information table before recording the preferred route information in the preferred route information table. 10. A system for selecting a transmission path, comprising a network device and a server, wherein: The network device is configured to receive a DHCP response message from the server, the DHCP response message includes the IP address of the client, obtains preferred path information according to the DHCP response message, and the preferred path information includes the The IP address of the client and the port identification of the DHCP response message; record the preferred path information in the preferred path information table; the network device is also used to receive data packets, according to the source IP of the data packets address query the preferred path information table, when the source IP address of the data message is the same as the IP address of an existing preferred path information in the preferred path information table, from the port of the existing preferred path information Identify the corresponding port to forward the data message. 11. The system according to claim 8, wherein the network device is also used for when the source IP address of the data message and any one of the IP addresses in the preferred path information table that already have preferred path information When the addresses are different, the data message is forwarded according to the routing table.

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