WO2012167559A1

WO2012167559A1 - Method and triple layer device for fast forwarding data packets

Info

Publication number: WO2012167559A1
Application number: PCT/CN2011/082301
Authority: WO
Inventors: 郭红燕; 靳海燕; 王日红
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-06-10
Filing date: 2011-11-16
Publication date: 2012-12-13
Also published as: CN102821032B; CN102821032A

Abstract

Disclosed in the present invention is a method for fast forwarding data packets, which comprises: a triple layer device estimates whether the packets can be fast forwarded; if so, then it rewrites the packets and forwards the packets directly; if not so, it transfers the packets to its own protocol stack and forwards the packets after processed by the protocol stack. The present invention also discloses a triple layer device for fast forwarding data packets. The present invention enables the triple layer device reducing repetition work of forwarding data packets and improving speed of forwarding data packets.

Description

Method for quickly forwarding data packets and three-layer device

The present invention relates to routing technologies in the field of communications, and in particular, to a method for rapidly forwarding data packets and a three-layer device. Background technique

The network is increasingly becoming an indispensable tool in people's daily lives. Almost everyone uses the Internet to query data, send and receive emails, and play online games. Users are increasingly demanding data transmission speeds. In a network, the speed of data transmission depends on the device that acts as a route, such as a Layer 3 device.

At present, the three-layer device needs to undergo a large amount of processing for forwarding data packets. The processing process includes: after receiving the data packet, the three-layer device performs type identification of the data packet, records the receiving port number, and then performs a series of processing such as path finding by the protocol stack. , the packet is sent after the processing is completed. However, all packets that are normally forwarded by a Layer 3 device use the same path.

It can be seen that the three-layer device does a lot of repetitive work in the process of forwarding, thereby seriously reducing the speed of packet forwarding. Summary of the invention

In view of the above, the object of the present invention is to provide a method for rapidly forwarding data packets and a Layer 3 device, which can reduce the repetitive work performed by the Layer 3 device to forward data packets and improve the packet forwarding speed.

In order to achieve the above object, the technical solution of the present invention is achieved as follows:

The present invention provides a method for rapidly forwarding a data packet, the method comprising the following steps: The layer 3 device determines whether the data packet can be quickly forwarded, and if so, rewrites the data packet and forwards the data packet; if not, the data packet It is forwarded by the protocol stack and then forwarded. In the foregoing solution, the determining whether the data packet can be quickly forwarded includes: if the Internet Protocol (IP) version number in the data packet is IPV4 or IPV6, the fragment identifier in the data packet is not fragmented, and the data packet is in the data packet. The IP protocol is the Transmission Control Protocol (TCP) or the User Datagram Protocol (UDP), and the five records recorded in the five-group and three-layer devices in the data packet are recorded in any one of the forwarding tables. If the tuples are the same, the data packets can be forwarded quickly, and vice versa.

In the above solution, the rewriting the data packet includes: the three-layer device uses the quintuple of the data packet to select a forwarding table, and then uses the information in the forwarding table to control the source medium access control (MAC, Media Access Control) in the data packet. Address, destination MAC address, IP address after NAT (Network Address Translation), port number after NAT, and virtual local area network (VLAN) value replacement.

In the foregoing solution, the forwarding table is related information that records a data packet that can be quickly forwarded in a connection, and specific content that needs to be rewritten when the data packet is quickly forwarded; the related information includes: a quintuple, a NAT type, The IP address after the NAT, the port number after the NAT, the source MAC address, the destination MAC address, and the VLAN value when the packet is sent. The Layer 3 device has multiple forwarding tables at the same time. The identifier of the forwarding table.

In the foregoing solution, before the forwarding, the method further includes: determining, by the third layer device, whether the data packet to be forwarded satisfies a condition for establishing a forwarding table for the connection that is in the connection, and if not, does not establish a forwarding table, if the condition is met. Then, the forwarding table is created and saved by using the information in the connection tracking table and the related information in the data packet to be sent.

In the foregoing solution, the condition for establishing the forwarding table includes: the three-layer device finds the corresponding connection tracking table according to the quintuple in the data packet, and the usage record of the help function in the connection tracking table is unused, and the IP protocol is TCP. Or UDP, and the connection status is the established connection, the forwarding identifier is forwarded; the layer 3 device checks the fragment identifier in the data packet as unfragmented; the layer 3 device extracts the quintuple of the data packet, using the quintuple group Lookup in the forwarding table already in the Layer 3 device, not found Record the forwarding table for the five-tuple.

In the above solution, after the forwarding, the method further includes: the three-layer device starts the timer in the connection tracking table after any one of the connection tracking tables is completed, and after the timer expires, the three-layer device queries the same five. If the forwarding table is not accessed between the current query and the last query, the Layer 3 device deletes the forwarding table and deletes the connection tracking table; otherwise, no operation is performed.

The present invention further provides a Layer 3 device for rapidly forwarding data packets, where the Layer 3 device includes: a fast forwarding module, a protocol processing module, and a sending module;

The fast forwarding module is configured to determine whether the data packet can be quickly forwarded. When the data packet can be quickly forwarded, the data packet is rewritten and sent to the sending module. When the data packet cannot be quickly forwarded, the data packet is sent to the protocol processing module.

a protocol processing module, configured to receive a data packet sent by the fast forwarding module, and send the data packet to the sending module after being processed by the protocol stack of the layer 3 device;

The sending module is configured to receive the rewritten data packet sent by the fast forwarding module, the processed data packet sent by the protocol processing module, and send the data packet.

In the foregoing solution, the fast forwarding module determines whether the data packet can be quickly forwarded as: extracting an IP version number, a fragment identifier, and a quintuple in the data packet. If the IP version number is IPV4 or IPV6, the fragment identifier is not divided. The IP protocol in the quintuple is TCP or UDP, and all the forwarding tables stored in the quintuple are used for comparison. If the same quintuple appears in the forwarding table, the packet It can be forwarded quickly, otherwise it cannot be forwarded quickly.

In the above solution, the fast forwarding module rewrites the data packet to: use the quintuple of the data packet to select the forwarding table, and then use the information in the forwarding table to use the source MAC address, the destination MAC address, and the NAT in the data packet. Replace the information such as the IP address, port number after NAT, and VLAN value.

In the above solution, the sending module is further configured to determine whether the data packet satisfies the condition for establishing a forwarding table before sending the data packet, and does not perform an operation when the condition is not met, and when the condition is met, The information required to establish the forwarding table in the data packet is sent to the fast forwarding module to be sent to the fast forwarding module. Correspondingly, the fast forwarding module is further configured to receive the information in the notification after receiving the notification of the forwarding table sent by the sending module. Obtaining the information required to establish a forwarding table in the connection tracking table from the protocol processing module, and establishing a forwarding table;

The protocol processing module is further configured to send, to the fast forwarding module, information required to establish a transfer in the connection tracking table.

In the above solution, the sending module is further configured to extract a quintuple and a shard identifier in the data packet, and obtain a corresponding connection tracking table from the protocol processing module by using the arbitrarily obtained acquisition request, if the connection tracking table is The usage of the help function is recorded as unused, the IP protocol is TCP or UDP, and the connection status is the established connection. The forwarding identifier is forwarded, the fragmentation identifier of the data packet is unfragmented, and the quintuple is used to write the ratio. Sending the comparison instruction to the fast forwarding module, and then receiving the comparison result returned by the fast forwarding module, the comparison result is that the forwarding table of the quintuple does not exist, and a forwarding table is established for the connection of the data packet;

Correspondingly, the protocol processing module is further configured to receive an acquisition request sent by the sending module, analyze the quintuple in the obtaining request, find the connection tracking table corresponding to the quintuple, and then send a connection tracking table to the sending module;

The fast forwarding module is further configured to receive a comparison instruction of the sending module, and extract a quintuple in the comparison instruction to find whether there is a forwarding table for recording the quintuple, and if yes, send the presence of the five to the sending module. The comparison result of the forwarding table of the tuple, if not, sends a comparison result of the forwarding table in which the quintuple does not exist to the transmitting module.

In the above solution, the protocol processing module is further configured to enable a timer in the connection tracking table after any one of the connection tracking tables is completed. When the timer expires, the received response is a forwarding table in this time. If the query and the last query have never been accessed, delete the connection tracking table and send the finger to the fast forwarding module to delete the forwarding table with the same five-tuple. Order, otherwise do not operate;

Correspondingly, the fast forwarding module is further configured to receive the query information of the protocol processing module, and send the reply information that has never been visited between the current query and the last query according to the usage of the forwarding table or in the present The reply information that has been accessed between the secondary query and the last query is deleted by the receiving protocol processing module and deleting the forwarding table having the same five-tuple forwarding table.

In the foregoing solution, the Layer 3 device includes: a packet receiving module, configured to receive a data packet, determine whether the fast forwarding module is enabled, and if it is enabled, send the data packet to the fast forwarding module, if not, the data packet is Sent to the protocol processing module;

Correspondingly, the fast forwarding module is further configured to send a start notification to the packet receiving module, and receive the data packet sent by the packet receiving module;

The protocol processing module is further configured to receive a data packet sent by the packet receiving module.

The method for rapidly forwarding data packets and the three-layer device provided by the invention have the following advantages and features: The three-layer device can use the quintuple of the data packet to determine whether it can be quickly forwarded, so that the same connection is received by the three-layer device. The data packets do not need to be forwarded and uploaded to the protocol stack for processing, so that the data packet transmission time can be greatly reduced, and the repetitive work of the Layer 3 device forwarding the data packets in the same connection is reduced. In turn, the packet forwarding speed of the Layer 3 device is improved. DRAWINGS

1 is a schematic flowchart of an implementation process of a method for rapidly forwarding a data packet according to the present invention;

FIG. 2 is a schematic structural diagram of a three-layer device for rapidly forwarding data packets according to the present invention. detailed description

The basic idea of the present invention is: The three-layer device determines whether the data packet can be quickly forwarded, and if so, the data packet is rewritten and directly forwarded; if not, the data packet is forwarded by the protocol stack and then forwarded. The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in FIG. 1 , the method for rapidly forwarding a data packet includes the following steps: Step 101: After receiving a data packet, the layer 3 device determines whether the data packet can be quickly forwarded. If yes, step 102 is performed, if not, , step 103 is performed;

Here, the data packet mainly includes: a quintuple, a VLAN value, a fragment identifier, an IP version number, a source MAC address, a destination MAC address, and the like; wherein, the quintuple refers to: an IP source address,

IP destination address, source port, destination port, and IP protocol number.

In this step, the determining whether the data packet can be quickly forwarded includes: if the data packet

The IP version number is IPV4 or IPV6. The fragment ID in the data packet is not fragmented. The IP protocol in the data packet is TCP, or UDP. Any one of the five-group and three-layer devices in the data packet is transferred. If the quintuple recorded in the publication is the same, the data packet can be forwarded quickly, and vice versa.

The forwarding table records the related information of the data packet that can be quickly forwarded in the connection and the specific content that needs to be rewritten when the data packet is quickly forwarded; the forwarding table includes: a quintuple, a NAT type, and an IP after the NAT The address, the port number after the NAT, the source MAC address, the destination MAC address, and the VLAN value when the packet is sent. The Layer 3 device can have multiple forwarding tables at the same time. The quintuple is used to distinguish the identifiers of the forwarding tables. .

Step 102: The layer 3 device selects the forwarding table by using the quintuple of the data packet, and rewrites the data packet by using the information in the forwarding table, and then performs step 104;

Here, the rewriting data packet refers to replacing the content in the related field in the data packet according to the information in the forwarding table, and the replaced content includes: a source MAC address, a destination MAC address, an IP address and a port number after the NAT, and a VLAN value. .

Step 103: The layer 3 device hands over the data packet to its own protocol stack for processing;

In step 103, the processing process of the protocol stack is determined by the processing function existing in the three-layer device. During the processing of the protocol stack, the three-layer device performs NAT on the data packet, and modifies the source of the data packet. MAC address, destination MAC address, and modification of the VLAN value, and finally select the sending port for the data packet;

The Layer 3 device also uses connection tracking technology to record information about packets at different stages, and uses this information to establish a connection tracking table for the connection to which the packet resides. The connection tracking table includes: 5-tuple, NAT type, NAT IP address, port number after NAT, source MAC address when the packet is sent, destination MAC address, timer, status of the connection, forwarding identifier, usage record of the help function, etc.

Step 104: Add a data packet to the sending queue, and determine whether the data packet meets the condition for establishing a forwarding table. If the condition is met, a forwarding table is established for the connection where the data packet is located. If the condition is not met, the forwarding table is not established.

Here, the sending queue is a FIFO (First Input First Output) queue set by a three-layer device.

The establishing the forwarding table refers to: firstly selecting a corresponding connection tracking table by using a quintuple in the data packet, and then extracting a NAT type in the connection tracking table, an IP address after NAT, a port number after NAT, and the like; The source MAC address, the destination MAC address and the VLAN value, and the PPP header content when the data packet is sent are extracted from the packet. Finally, the forwarding table is created and saved by using the extracted content.

Whether the condition for establishing the forwarding table is satisfied includes: checking, according to the quintuple in the data packet, the connection tracking table of the connection where the data packet is located, whether the usage record of the help function in the connection tracking table is unused, and whether the IP protocol is TCP or UDP, and whether the connection status is an established connection, whether the forwarding identifier is forwarded or not; check whether the fragment identifier in the data packet is unfragmented; and check whether there is an existing forwarding table in the Layer 3 device. Record the forwarding table for the quintuple.

Step 105: The layer 3 device extracts the data packet from the sending queue for transmission.

After the above steps, the forwarding of data packets that are forwarded locally through a connection can be completed. The Layer 3 device can be set by software according to the actual situation. In addition, after the step 105 is completed, the layer 3 device also deletes the forwarding table, and the deleting process includes: After the third layer device completes any operation in any one of the connection tracking tables, the timer of the connection tracking table is started, and when the timer expires The Layer 3 device queries the usage of the forwarding table with the same five-tuple. If the forwarding table is not accessed between the current query and the last query, the Layer 3 device deletes the forwarding table and deletes the connection tracking. Table; otherwise no action.

Here, any one of the operations refers to all operations in the three-layer device regarding the connection tracking table, such as: querying or extracting information of the connection tracking table when the forwarding table is established, and processing the data packet when the protocol stack of the three-layer device processes the data packet. The operation of the connection tracking table for information extraction of the data packet and status recording;

The forwarding table is accessed, and refers to: In the foregoing steps 101 and 102, the layer 3 device uses the forwarding table to compare with the data packet, and uses the forwarding table to rewrite the data packet.

To implement the foregoing method, as shown in FIG. 2, the three-layer device for rapidly forwarding data packets of the present invention includes: a fast forwarding module 21, a protocol processing module 22, and a sending module 23;

The fast forwarding module 21 is configured to determine whether the data packet can be quickly forwarded. When the data packet can be quickly forwarded, the data packet is rewritten and sent to the sending module. When the data packet cannot be quickly forwarded, the data packet is sent to the protocol processing module.

Here, the data packet includes: an IP source address, an IP destination address, a source port, a destination port, an IP protocol, a VLAN value, a fragment identifier, an IP protocol version number, a PPP encapsulation identifier source MAC address, and a gateway MAC address. Etc.; The quintuple refers to: IP source address, IP destination address, source port, destination port, and ten office number.

The protocol processing module 22 is configured to receive the data packet sent by the fast forwarding module, and process the data packet to the sending module after being processed by the protocol stack of the layer 3 device.

Here, the specific process of the protocol processing module processing the data packet is determined by the processing function existing in the three-layer device.

The sending module 23 is configured to receive the rewritten data packet sent by the fast forwarding module, and The processed data packet sent by the processing module is sent, and the data packet is sent.

Here, the sending of the data packet refers to the sending of the data packet from the queue after the data packet is placed in the FIFO queue.

The fast forwarding module 21 is specifically configured to extract an IP protocol version number, a fragment identifier, an IP protocol, and a quintuple in the data packet. If the IP protocol version number in the data packet is IPV4 or IPV6, the packet in the data packet The slice identifier is not fragmented. The IP protocol in the data packet is TCP or UDP, and the quintuple in the data packet is the same as the quintuple recorded in the forwarding table. The data packet can be forwarded quickly, otherwise the data packet cannot be fast. Forward.

The fast forwarding module 21 is further configured to select a forwarding table by using a quintuple of the data packet, and then use the information in the forwarding table to access the source medium in the data packet to control the MAC address, the destination MAC address, the IP address after the NAT, Replace the port number after the NAT, the VLAN value of the virtual LAN, and so on;

The forwarding table records information about a data packet that can be quickly forwarded, and the information includes: a quintuple, a NAT type, an IP address after NAT, a port number after NAT, a source MAC address, a MAC address of a gateway, and a VLAN value. The content of the quintuple refers to the IP source address, the IP destination address, the source port, the destination port, and the ten-party negotiation number.

The fast forwarding module 21 is also used to save the forwarding table.

The sending module 23 is further configured to determine whether the data packet satisfies the condition for establishing a forwarding table for the connection before the data packet is sent, and does not perform the operation when the condition is not met; when the condition is met, the forwarding table is established in the data packet. The notification that the information is written to establish the forwarding table is sent to the fast forwarding module 21; correspondingly, the fast forwarding module 21 is further configured to receive the information in the notification after the notification of the forwarding table sent by the sending module 23, and the protocol processing module 22: Obtain the information required to establish the forwarding table in the connection tracking table, and finally establish a forwarding table. The protocol processing module 22 is further configured to send, to the fast forwarding module 21, information required to establish a forwarding table in the connection tracking table.

The sending module 23 is further configured to extract a quintuple and a fragment identifier in the data packet, and utilize the five The acquisition request written by the tuple obtains the corresponding connection tracking table from the protocol processing module 22. If the usage record of the help function in the connection tracking table is unused, the IP protocol is TCP or UDP, and the connection status is an established connection. The forwarding identifier is forwarded, and the fragment identifier of the data packet is unfragmented, and then the quintuple is used to write the comparison instruction, and the comparison instruction is sent to the fast forwarding module 21; after receiving the comparison result sent by the fast forwarding module, If the result is that there is no forwarding table of the quintuple, a forwarding table is established for the connection where the data packet is located;

Correspondingly, the protocol processing module 22 is further configured to receive the acquisition request sent by the sending module, analyze the quintuple in the obtaining request, find the connection tracking table corresponding to the quintuple, and then send the connection tracking to the sending module 23. The fast forwarding module 21 is further configured to receive the comparison instruction of the sending module 23, and extract the quintuple in the comparison instruction to find out whether the forwarding table of the quintuple is recorded, and if yes, send The module 23 transmits the comparison result of the forwarding table in which the quintu is present, and if not, transmits the comparison result of the forwarding table in which the quintuple does not exist to the transmitting module 23.

The protocol processing module 22 is specifically configured to process a data packet by using an existing processing function, perform NAT on the data packet, modify a source MAC address, a destination MAC address, and a modified VLAN value of the data packet, and finally Selecting a sending port for the data packet; also for using the connection tracking technology to record information about packets at different stages, and using the information to establish a connection tracking table of the connection where the data packet is located;

The connection tracking table includes: a quintuple, a NAT type, an IP address after NAT, a port number after NAT, a source MAC address when the data packet is sent, a destination MAC address, a timer, a connection status, and a forwarding identifier. Information such as the usage record of the help function.

The protocol processing module 22 is further configured to: after any one of the connection tracking tables completes any operation, start a timer in the connection tracking table, and when the timer expires, reply to the fast forwarding to the forwarding table in the query and If the secondary query has never been accessed, the connection tracking table is deleted, and the fast forwarding module 21 is sent an instruction to delete the forwarding table having the same five-tuple. Otherwise do not operate;

Correspondingly, the fast forwarding module 21 is further configured to receive the query information of the protocol processing module 22, and send the reply information that has never been visited between the current query and the last query according to the usage of the forwarding table or The reply information that has been accessed between the current query and the last query deletes the forwarding table after receiving the instruction sent by the protocol processing module 22 to delete the forwarding table having the same five-tuple.

The above-mentioned three-layer device further includes: a packet receiving module 24, configured to receive a data packet, determine whether the fast forwarding module 21 is enabled, and if it is enabled, send the data packet to the fast forwarding module 21, if not, the data is The packet is sent to the protocol processing module 22;

Correspondingly, the fast forwarding module 21 is further configured to send a start notification to the message receiving module 24, and receive the data packet sent by the message receiving module 24. The protocol processing module 22 is further configured to receive the data packet sent by the message receiving module 24. .

The fast forwarding module 21 can determine whether to enable according to the actual situation.

It can be seen that the packet forwarding operation in the locally forwarded connection can be completed by using the above module, and the fast forwarding module can be started according to the actual situation.

With the above solution, in the process of processing all the data packets of a forwarding connection, the data packets that meet the conditions of the forwarding table are forwarded in advance, so that the processing of the protocol stack of the three-layer device can be reduced, and the three-layer device can be improved. The purpose of processing speed.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

Claim

A method for rapidly forwarding a data packet, the method comprising:

The Layer 3 device determines whether the data packet can be forwarded quickly. If it can, the data packet is rewritten and then forwarded. If not, the data packet is forwarded by the protocol stack and then forwarded.

2. The method according to claim 1, wherein the determining whether the data packet can be quickly forwarded comprises: if the Internet Protocol IP version number in the data packet is IPV4 or IPV6, the fragment identifier in the data packet is not Fragmentation, the IP protocol in the data packet is the Transmission Control Protocol TCP or the User Datagram Protocol UDP, and the quintuple in the data packet is the same as the quintuple recorded in any one of the forwarding tables stored in the Layer 3 device, then the data Packets can be forwarded quickly, and vice versa cannot be forwarded quickly.

The method according to claim 1, wherein the rewriting the data packet comprises: the three-layer device uses the quintuple of the data packet to select a forwarding table, and then uses the information in the forwarding table to The source medium access control MAC address, destination MAC address, IP address after network address translation NAT, port number after NAT, and virtual LAN VLAN value are replaced.

The method according to claim 3, wherein the forwarding table is related information that records a data packet that can be quickly forwarded in a connection, and specific content that needs to be rewritten when the data packet is quickly forwarded; Related information includes: quintuple, NAT type, IP address after NAT, port number after NAT, source MAC address, destination MAC address, and VLAN value when the packet is sent. Published, using a five-tuple as an identifier to distinguish each forwarding table.

The method according to claim 1, wherein before the forwarding, the method further comprises: the layer 3 device determining whether the data packet to be forwarded satisfies the condition for establishing a forwarding table for the connection in which it is located, if not If it is satisfied, the forwarding table is not established. If the condition is met, the forwarding table is created and saved by using the information in the connection tracking table and the related information in the data packet to be transmitted.

6. The method according to claim 5, wherein the data packet is satisfied The conditions for establishing a forwarding table for the connection are as follows: According to the quintuple in the data packet, the corresponding connection tracking table is found, whether the usage record of the help function in the connection tracking table is unused, whether the IP protocol is TCP or UDP, and Whether the connection status is an established connection, whether the forwarding identifier is forwarded or not; whether the fragmentation identifier in the data packet is unfragmented; and whether the five-yuan is recorded in the forwarding table already existing in the three-layer device. Group forwarding table.

The method according to claim 1, wherein after the forwarding, the method further comprises: the three-layer device starting the timer in the connection tracking table after any one of the connection tracking tables is completed, when the timing is After the device times out, the Layer 3 device queries the forwarding table of the same quintuple. If the forwarding table is not accessed between the current query and the last query, the Layer 3 device deletes the forwarding table and deletes the table. The connection tracking table; otherwise, no action is taken.

A three-layer device for rapidly forwarding data packets, wherein the three-layer device includes: a fast forwarding module, a protocol processing module, and a sending module;

The fast forwarding module is configured to determine whether the data packet can be forwarded quickly. When the data packet can be quickly forwarded, the data packet is rewritten and sent to the sending module. When the data packet cannot be quickly forwarded, the data packet is sent to the protocol processing module.

The Layer 3 device according to claim 8, wherein the fast forwarding module determines whether the data packet can be quickly forwarded as: extracting an IP version number, a fragment identifier, and a quintuple in the data packet, if the IP The version number is IPV4 or IPV6. The fragment ID is not fragmented. The IP protocol in the quintuple is TCP or UDP, and the quintuple is compared with all the forwarding tables saved in the module. If there are the same five When a tuple appears in the forwarding table, the data packet can be forwarded quickly, and vice versa.

The Layer 3 device according to claim 8, wherein the fast forwarding module rewrites the data packet to: use a quintuple of the data packet to select a forwarding table, and then use the information in the forwarding table to use the data packet. The source MAC address, destination MAC address, IP address after NAT, port number after NAT, and VLAN value are replaced.

11. The three-layer device according to claim 8, wherein

The sending module is further configured to determine, before sending the data packet, whether the data packet satisfies the condition for establishing a forwarding table for the data packet, and does not operate when the condition is not met. When the condition is met, the information required to establish the forwarding table in the data packet is written as The notification of establishing the forwarding table is sent to the fast forwarding module;

Correspondingly, the fast forwarding module is further configured to: after receiving the notification of the forwarding table sent by the sending module, extract the information in the notification, obtain the information required to establish the forwarding table in the connection tracking table from the protocol processing module, and establish a forwarding table;

The three-layer device according to claim 11, wherein the sending module is further configured to extract a quintuple and a shard identifier in the data packet, and use the quintuple to obtain an acquisition request from the protocol processing module. Obtain the corresponding connection tracking table, if the usage record of the help function in the connection tracking table is unused, the IP protocol is TCP or UDP, and the connection status is established connection, the forwarding identifier is forwarded, and the packet is fragmented. The identifier is not fragmented, and the quintuple is used to write the comparison instruction, and the comparison instruction is sent to the fast forwarding module, and then the comparison result returned by the fast forwarding module is received, and the comparison result is that the quintuple does not exist. Publish, establish a forwarding table for the connection where the data packet is located;

Correspondingly, the protocol processing module is further configured to receive an acquisition request sent by the sending module, analyze the quintuple in the obtaining request, find the connection tracking table corresponding to the quintuple, and then send a connection tracking table to the sending module. ;

The fast forwarding module is further configured to receive a comparison instruction of the sending module, and extract the comparison instruction. After the quintuple in the middle, it is searched whether there is a forwarding table for recording the quintuple, and if so, the comparison result of the forwarding table in which the quintu is present is sent to the sending module, and if not, the non-existing node is sent to the sending module. The comparison result of the five-tuple forwarding table.

13. The three-layer device according to claim 8, wherein

The protocol processing module is further configured to start a timer in the connection tracking table after any one of the connection tracking tables completes the operation, and after the timer expires, the fast forwarding is forwarded to the forwarding table in the query and If the secondary query has never been accessed, the connection tracking table is deleted, and the instruction for deleting the forwarding table with the same five-tuple is sent to the fast forwarding module, otherwise the operation is not performed;

Correspondingly, the fast forwarding module is further configured to receive the query information of the protocol processing module, and send the reply information that has never been visited between the current query and the last query according to the usage of the forwarding table or in the present The reply message that has been accessed between the secondary query and the last query deletes the forwarding table after receiving an instruction sent by the protocol processing module to delete the forwarding table having the same five-tuple.

The Layer 3 device according to claim 8, wherein the Layer 3 device comprises: a message receiving module, configured to receive a data packet, determine whether the fast forwarding module is enabled, and if enabled, send the data packet. To the fast forwarding module, if not, sending the data packet to the protocol processing module;