WO2017219777A1 - Packet processing method and device - Google Patents

Abstract

Provided are a packet processing method and device. The packet processing method is applied to the packet processing device, and comprises: when receiving a dynamic host configuration protocol (DHCP) response packet sent to a DHCP client by a DHCP server, generating an address resolution protocol (ARP) record for the DHCP response packet, a DHCP tag being provided in the ARP record; and when a timing time in the ARP record is reached, deleting the ARP record. In the solution, by deleting an ARP record related to a DHCP when a timing time in the ARP record is reached, the dynamic updating of an ARP table is realised, and the problem of high network arrangement costs due to the limitation of the ARP table is avoided. The present invention reduces network arrangement costs.

Description

Message processing method and device Technical field

The present invention relates to the field of communications technologies, and in particular, to a packet processing method and apparatus.

Background technique

The Dynamic Host Configuration Protocol (DHCP) is a protocol that a network host applies to the server to dynamically obtain an IP address and host configuration information that allows it to communicate normally. RFC 2131 details DHCP. DHCP uses the User Datagram Protocol (UDP) as the transport protocol. The host sends a message to port 67 of the DHCP server. The DHCP server sends a message back to port 68 of the host.

The work of DHCP is mainly divided into the following steps:

1. The host sends a DHCP packet (DHCP Discovery Packet) that requests the IP address and other configuration parameters.

2. The DHCP server sends back a DHCP Offer (DHCP Response Packet) containing a valid IP address and configuration.

3. The host selects the server of the DHCP Offer that arrives first, and sends a unicast message DHCP request (DHCP request message) to the user to accept the relevant configuration;

4. The selected DHCP server sends back an acknowledged unicast packet DHCP Ack (DHCP response packet).

Through the above steps, the host can communicate using the IP address obtained from the DHCP server and related configuration. The effective use period of the address is the lease period. Before the lease expires, the host must request the server to continue to lease. The server accepts the request to continue to use, otherwise it will give up unconditionally.

DHCP packets are broadcasted and cannot pass through multiple different subnets. If DHCP packets need to traverse multiple different subnets, you need to configure DHCP relay. DHCP relay can be configured on the router and can be configured on the DHCP client. Its main function The message is delivered to the DHCP server that is not on the same subnet as the client, and the return message of the DHCP server is sent back to the DHCP client to complete the allocation and management of the dynamic address of the DHCP client.

DHCP relay mode: The DHCP relay agent listens to all packets with the UDP destination port number 67 (that is, packets sent to the DHCP server). After receiving the request packet, the DHCP relay agent converts the broadcast request message into a unicast message according to the pre-defined DHCP server address, and fills in its own proxy address and sends it to the DHCP server.

With the development of technology, the capacity of the DHCP server is getting larger and larger, and the actual use is limited by the capacity of the address resolution protocol (ARP) table of the DHCP relay. A router that purchases expensive, large ARP table capacity in the network.

Summary of the invention

The technical problem to be solved by the embodiments of the present invention is to provide a packet processing method and apparatus, which are used to solve the problem that the cost of the network is high due to the limitation of the capacity of the ARP table of the existing DHCP relay.

In order to solve the above technical problem, an embodiment of the present invention provides a packet processing method, which is applied to a packet processing apparatus, and includes:

After receiving the DHCP response message sent by the dynamic host configuration protocol DHCP server to the DHCP client, generating an address resolution protocol ARP record for the DHCP response message, where the ARP record is provided with a DHCP tag;

The ARP record is deleted when the timing time in the ARP record arrives.

Further, when the timing time in the ARP record arrives, the packet processing method further includes:

Control stops sending ARP probe packets to the DHCP client.

Further, when receiving the DHCP response message sent by the DHCP server to the DHCP client, the message processing method further includes:

Establishing a direct route between the packet processing device and the DHCP client.

Further, when receiving the DHCP response message sent by the DHCP server to the DHCP client, the message processing method further includes:

Sending the DHCP response message to the DHCP client.

Further, the timing time is 1000 milliseconds.

An embodiment of the present invention provides a packet processing apparatus, including:

a generating module, configured to generate an address resolution protocol ARP record for the DHCP response message when receiving a DHCP response message sent by the dynamic host configuration protocol DHCP server to the DHCP client, where the ARP record is provided with a DHCP tag;

The deleting module is set to delete the ARP record when the timing time in the ARP record arrives.

Further, the message processing apparatus further includes:

The control module is configured to stop sending ARP probe packets to the DHCP client.

Further, the message processing apparatus further includes:

The route establishing module is configured to establish a direct route between the packet processing device and the DHCP client.

Further, the message processing apparatus further includes:

The sending module is configured to send the DHCP response message to the DHCP client.

Further, the timing time is 1000 milliseconds.

In the embodiment of the present invention, a computer storage medium is further provided, and the computer storage medium may store an execution instruction for executing the implementation of the message processing method in the foregoing embodiment.

The beneficial effects of the embodiments of the present invention are:

In the above solution, when the ARP record related to the ARP record is deleted, the ARP record related to the DHCP is deleted, and the dynamic update of the ARP table is realized, thereby avoiding the problem that the network cost is high due to the limitation of the ARP table, and the present invention is reduced. Distribution cost.

DRAWINGS

1 is a schematic flowchart of a packet processing method according to Embodiment 1 of the present invention;

2 is a schematic flowchart of processing a response packet by a DHCP relay;

Figure 3 is a scenario in which a common DHCP client obtains an IP address through a DHCP relay.

4 is a scenario in which a DHCP client obtains an IP address through N DHCP relays;

Figure 5 is a scenario in which a DHCP client obtains an IP address through an IP RAN network.

FIG. 6 is a schematic block diagram of a message processing apparatus according to Embodiment 2 of the present invention.

detailed description

The present invention will be described in detail below with reference to the drawings and specific embodiments.

The present invention provides a message processing method and apparatus for the problem of high network cost due to the limitation of the capacity of the existing DHCP relay ARP table.

Embodiment 1

As shown in FIG. 1, the packet processing method in the first embodiment of the present invention is applied to a message processing apparatus, including:

Step 11: When receiving a DHCP response message sent by the dynamic host configuration protocol DHCP server to the DHCP client, generate an address resolution protocol ARP record for the DHCP response message, where the ARP record is provided with a DHCP tag;

Step 12: Delete the ARP record when the timing time in the ARP record arrives.

It should be noted that the aging time of the ARP record is the aging time of the ARP record. Generally, the aging time is 1000 milliseconds, and the aging time can be set according to the application.

In the embodiment of the present invention, when the ARP record related to the ARP record is deleted, the ARP record related to the DHCP is deleted, and the dynamic update of the ARP table is implemented, thereby avoiding the problem that the network cost is high due to the limitation of the ARP table, and the present invention Reduced the cost of the network.

It should be noted that, in general, the message processing device is called a DHCP relay. It is usually set in the router or on the DHCP client side. The ARP entries of the original DHCP packets are not automatically deleted. In this case, if too many DHCP clients are connected to the network, the number of ARP entries will be too large, and the DHCP relay will be used for each ARP entry. The ARP probe packet is always sent. In this application, the ARP entry is automatically deleted after the aging time of the ARP entry is reached. Therefore, the ARP probe packet will not be sent again. Therefore, the time is reached in the ARP record. The message processing method further includes:

Control stops sending ARP probe packets to the DHCP client.

It should be noted that, when receiving the DHCP response message sent by the DHCP server to the DHCP client, the DHCP relay needs to establish a direct connection between the DHCP relay and the DHCP client, and simultaneously set the DHCP response. The message is sent to the DHCP client.

The specific working process of DHCP relay includes:

After receiving the DHCP Discover message, the DHCP relay replaces the source IP address of the packet and checks the route to forward the packet.

The DHCP relay agent receives the unicast DHCP Offer message, and the DHCP platform (refers to the protocol at the DHCP level of the router and the DHCP relay agent at the same level) specifies that the packet is sent to the DHCP client.

The DHCP relay agent receives the unicast DHCP Request message, and the same route is forwarded to the DHCP server.

Then, the DHCP relay process uses the method described in the present invention to process the received response message, as shown in FIG. 2, and the specific processing process includes:

Step 21: The DHCP relay receives a response packet without a route.

Step 22, it is determined whether the response message is a DHCP message; if it is not a DHCP message, step 23 is performed; otherwise, step 24 is performed;

Step 23, generating a normal dynamic ARP entry;

Step 24: Generate an ARP entry with a D flag, so that the ARP entry is a DHCP ARP entry, and the D-flagged message is sent to the DHCP platform, that is, the DHCP platform receives the ARP response packet and finds that I learned the IP address with a special D mark, so I was born. D mark in the age item of the ARP entry;

Step 25: Configure a timer. If the timer expires, determine whether the timeout ARP entry is marked with D. If the D flag is marked, go to step 27. Otherwise, go to step 28.

It should be noted that the default aging time of the D-marked ARP entry is 1000 milliseconds, and the aging time can be configured. For example, the router with the D-marked ARP entry has a shorter aging time configuration. The stronger the ability.

Step 27: After the aging, the ARP detection packet is not sent, and the ARP entry is automatically deleted.

Step 28: After the aging, the device sends a gratuitous ARP probe packet, and receives the response packet to update the aging time of the ARP entry.

The specific application scenarios of the present invention are specifically described below as follows:

As shown in Figure 3, a common DHCP client obtains an IP address through a DHCP relay. The DHCP relay uses the method of the present invention to process a DHCP response message.

As shown in FIG. 4, the DHCP client obtains an IP address through N DHCP relays, wherein the DHCP relay 1 processes the DHCP response message by using the method of the present invention.

As shown in FIG. 5, the DHCP client traverses the IP RAN network to obtain an IP address. The Layer 2 and Layer 3 bridge device (L2L3bridge) processes the DHCP response packet by using the method of the present invention.

In the embodiment of the present invention, the dynamic update of the ARP table is implemented, and the problem of high network cost due to the limitation of the ARP table is avoided, and the present invention reduces the cost of the network.

Embodiment 2

As shown in FIG. 6, the packet processing apparatus of the second embodiment of the present invention includes:

The generating module 61 is configured to: when receiving the DHCP response message sent by the dynamic host configuration protocol DHCP server to the DHCP client, generate an address resolution protocol ARP record for the DHCP response message, where the ARP record is set with a DHCP tag ;

The deleting module 62 is configured to delete the ARP record when the timing time in the ARP record arrives.

Optionally, the packet processing device further includes:

The control module is configured to stop sending ARP probe packets to the DHCP client.

Optionally, the packet processing device further includes:

The route establishing module is configured to establish a direct route between the packet processing device and the DHCP client.

Optionally, the packet processing device further includes:

The sending module is configured to send the DHCP response message to the DHCP client.

Specifically, the timing time is 1000 milliseconds.

It is to be noted that the packet processing apparatus of the present embodiment is the packet processing apparatus corresponding to the packet processing method of the first embodiment. All the implementation manners of the first embodiment are applicable to the embodiment, and can also be implemented and implemented. Example 1 has the same technical effect.

It will be apparent to those skilled in the art that the various modules or steps of the present invention described above can be implemented by a general-purpose computing device that can be centralized on a single computing device or distributed across a network 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 thereof 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 a preferred embodiment of the present invention, and it should be noted that those skilled in the art can also make several improvements and retouchings without departing from the principles of the present invention. Within the scope of protection of the invention.

Industrial applicability

The foregoing technical solution provided by the embodiment of the present invention can be applied to a packet processing process. In the foregoing solution, the ARP record related to the DHCP is deleted when the ARP recording time is reached, and the dynamic update of the ARP table is implemented to avoid The invention has a problem that the cost of the network is high due to the limitation of the ARP table, and the invention reduces the cost of the network.

Claims (10)

A packet processing method is applied to a message processing apparatus, including: After receiving the DHCP response message sent by the dynamic host configuration protocol DHCP server to the DHCP client, generating an address resolution protocol ARP record for the DHCP response message, where the ARP record is provided with a DHCP tag; The ARP record is deleted when the timing time in the ARP record arrives. The packet processing method according to claim 1, wherein the message processing method further comprises: when the timing time in the ARP record arrives: Control stops sending ARP probe packets to the DHCP client. The packet processing method according to claim 1, wherein the packet processing method further comprises: when receiving a DHCP response message sent by the DHCP server to the DHCP client: Establishing a direct route between the packet processing device and the DHCP client. The packet processing method according to claim 1, wherein the packet processing method further comprises: when receiving a DHCP response message sent by the DHCP server to the DHCP client: Sending the DHCP response message to the DHCP client. The message processing method according to claim 1, wherein said timing time is 1000 milliseconds. A message processing device comprising: a generating module, configured to generate an address resolution protocol ARP record for the DHCP response message when receiving a DHCP response message sent by the dynamic host configuration protocol DHCP server to the DHCP client, where the ARP record is provided with a DHCP tag; The deleting module is set to delete the ARP record when the timing time in the ARP record arrives. The message processing device according to claim 6, further comprising: The control module is configured to stop sending ARP probe packets to the DHCP client. The message processing device according to claim 6, further comprising: The route establishing module is configured to establish a direct route between the packet processing device and the DHCP client. The message processing device according to claim 6, further comprising: The sending module is configured to send the DHCP response message to the DHCP client. The message processing device according to claim 6, wherein said timing time is 1000 milliseconds.

Images