JP2009267684A - Packet processor and its packet processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packet processor such as a router corresponding to gigabit Ethernet having two or more MPU modules and its packet processing method. <P>SOLUTION: In the packet processor 10, a network processing part 12 presets provisional routing time shorter than a time-out period of ARP entry, when a packet in which the ARP entry is already registered is received, when receiving time of the packet reaches between the provisional routing time and ARP time-out period, packet loss to be generated when routing packets continuously reach processor 10 is suppressed, and high-speed routing is continued in an operation accompanying cooperation and update of the ARP entry by provisionally and autonomously routing the packet, and further updating an ARP timer by transmitting the packet to an application processing part 14. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a packet processing apparatus such as a Gigabit Ethernet compatible router having two or more MPU modules and a packet processing method thereof.

  In a network conforming to the Ethernet (registered trademark) standard, a packet processing device such as a router is provided as a relay point for packet communication. Such a router is configured to include at least one MPU (Micro Processing Unit), and can select and control an optimum route from communication routes in the network, that is, can perform routing processing of packets to be transmitted and received.

  A router needs only to have one MPU to process frames that flow through Ethernet at a general speed, but for example, a system that transfers packets at a communication speed of 1 Gbps or higher, that is, Gigabit Ethernet. Then, if the router performs routing processing with one MPU, the MPU and its peripheral circuits are forced to operate at high speed, and the price of the router's constituent circuit becomes high.

  Therefore, as a router supporting Gigabit Ethernet, it is configured to include a network processing unit having a hardware module with enhanced routing processing and an application processing unit having a software module mainly performing application processing such as routing control. Conventionally, a router in which each processing unit is equipped with an MPU and both modules operate cooperatively has been developed.

  In such a gigabit Ethernet router, the network processing unit and the application processing unit are connected via a dedicated bus, and the network processing unit is based on a routing entry and an ARP (Address Resolution Protocol) entry passed from the application processing unit. Perform routing processing.

  The application processing unit may be configured as a software module having, for example, a software stack that performs network processing according to the TCP / IP protocol.

  Further, the network processing unit has a port such as an RJ-45 connector and is configured to be connected to the network, and may perform routing through, for example, two ports.

  When a predetermined packet is received in this Gigabit Ethernet compatible router, the application processing unit processes this packet, and passes the ARP entry and routing entry corresponding to this packet to the network processing unit. The network processing unit registers these entries in its own table. Routing entries and ARP entries are managed independently.

  For example, the hardware module in the network processing unit may have a table storing routing entries and ARP entries necessary for routing control, and autonomously perform high-speed routing processing based on these two entries. In these two tables, no entry is stored in the initial state.

  The network processing unit provides an ARP timer for each ARP entry, and deletes the ARP entry from the table when a predetermined timeout period elapses after receiving the ARP entry. However, the network processing unit does not delete the routing entry according to the elapsed time since reception.

  Similarly, the application processing unit may also provide an ARP timer to delete the ARP entry from the table when a predetermined timeout time elapses, and does not delete the routing entry according to the elapsed time since reception. . Especially in the application processing unit, when a packet that matches the stored ARP entry arrives, the ARP timer is reset at the time of arrival.

  By the way, in the network management system described in Patent Document 1, the ARP management server changes the ARP table of each host computer connected to the network based on a request to change the ARP table of any host computer. Unnecessary broadcast packet generation can be prevented, the cause of packet loss can be reduced, network device processing related to broadcast packet forwarding and processing can be reduced, and ARP table update and management at the time of host relocation is centrally managed be able to.

Further, in the standby system switching system for redundant packet network described in Patent Document 2, the ARP packet period periodically transmitted from the active packet processing apparatus connected to the layer 2 switch is changed to the connection port destination of the layer 2 switch. By monitoring with the device failure detection circuit and detecting the failure, the layer 2 switch can detect the failure, the time from the failure detection to changing the configuration information to the standby system can be shortened, and standby Packet loss during system switching can be suppressed.
JP2003-348084 JP 2006-033467

  In a conventional packet processing apparatus in which the network processing unit and the application processing unit are configured to include MPUs respectively, the timeout time of the ARP entry in the network processing unit is shorter than the timeout time of the ARP entry in the application processing unit. There is a case. In other words, the ARP entry is registered in the application processing unit for a predetermined packet received by the apparatus, but may be deleted from the table due to a timeout in the network processing unit.

  In such a case, the network processing unit cannot autonomously route the packet related to the time-out ARP entry, and sends the packet to the application processing unit to register the ARP entry in the ARP table. Here, when a large number of packets related to the ARP entry reach the device, all the packets that arrived until the ARP entry is registered are sent to the application processing unit. Packets that cannot be generated. Further, such a packet that cannot be processed may be discarded.

  The present invention eliminates such drawbacks of the prior art, and a packet processing apparatus capable of suppressing packet loss when the data related to the packet operates in synchronization between two or more MPU modules and the packet thereof An object is to provide a processing method.

  In order to solve the above-described problem, the present invention includes a network processing unit that enhances routing processing, and an application processing unit that mainly performs application processing such as routing control. The network processing unit and the application processing unit include: Each of the network processing means and the application processing means includes a main control unit that performs overall control of its own operation, an ARP table that stores ARP entries related to received packets, and a routing table that stores routing entries. In addition, the network processing unit and the application processing unit measure the reception time of a packet related to a predetermined ARP entry registered in the ARP table by an ARP timer, and determine a predetermined timeout. In the packet processing device that deletes the predetermined ARP entry from the ARP table when it cannot be received before the time elapses, the network processing means sets a provisional routing time shorter than the predetermined timeout time in advance. When receiving a packet related to a predetermined ARP entry registered in the ARP table, if the packet is received before the provisional routing time elapses, the packet is autonomously routed and the packet Is received after the provisional routing time elapses and before the predetermined timeout period elapses, the packet is provisionally routed autonomously and further sent to the application processing means. The ARP timer is updated, and the packet is When receiving after a timeout period may send the packet to the application processing unit to re-register the predetermined ARP entry.

  In addition, the network processing unit and the application processing unit mainly control their own operations, including a network processing unit with enhanced routing processing and an application processing unit that mainly performs application processing such as routing control. Packet processing that includes a main control unit, an ARP table that stores ARP entries related to received packets, and a routing table that stores routing entries, and coordinates each entry between the network processing unit and the application processing unit The packet processing method of the apparatus measures the reception time of a packet related to a predetermined ARP entry registered in the ARP table for each of the network processing unit and the application processing unit using an ARP timer, and a predetermined timeout time elapses. The first step of deleting the predetermined ARP entry from the ARP table when it has not been received by the time, and the network processing unit presets a provisional routing time shorter than the predetermined timeout time. A second step of performing a routing process according to the reception time when a packet related to a predetermined ARP entry registered in the ARP table is received, and the second step When the packet is received before the lapse of the routing time, between the third step of autonomously routing the packet and the packet after the provisional routing time elapses and before the predetermined timeout time elapses. When received, the packet is provisionally routed autonomously and the packet is further routed to the application. A fourth step of sending the packet to the application processing unit and updating the ARP timer; and if the packet is received after the predetermined time-out period, the packet is sent to the application processing unit and the predetermined ARP And a fifth step of re-registering the entry.

  According to the packet processing device of the present invention, the network processing unit sets a provisional routing time shorter than the timeout time of the ARP entry in advance, and when receiving a packet in which the ARP entry has already been registered, the packet is provisionally routed. If the packet arrives by the time, the received packet is routed autonomously. If the packet arrives between the provisional routing time and the ARP timeout time, the received packet is provisionally routed autonomously. In addition, the received packet is sent to the application processing unit to update the ARP timer. If the packet arrives after the ARP timeout time, the received packet is sent to the application processing unit to re-register the ARP entry. As a result, routing packets arrive at this device continuously. Packet loss can be suppressed that occurs when it is possible to continue the high-speed routing in operation with coordination and updating ARP entries.

  Next, an embodiment of a packet processing device according to the present invention will be described in detail with reference to the accompanying drawings. For example, as shown in FIG. 1, the packet processing apparatus 10 such as a Gigabit Ethernet compatible router of the present invention mainly performs a network processing unit 12 having a hardware module with enhanced routing processing and application processing such as routing control. An application processing unit 14 having a software module is connected to the network 16, and these processing units 12 and 14 respectively have main control units 22 and 32 such as a microprocessor (MPU: Micro Processing Unit). It is configured to operate so that both modules cooperate. Note that portions not directly related to understanding the present invention are not shown and redundant description is avoided.

  The network processing unit (N unit) 12 reinforces the routing processing of the device 10. For example, among the packets received by the device 10, the application processing unit The routing process can be strengthened by performing the routing based on the registered entry without registering the entry according to 14.

  The network processing unit 12 of the present embodiment includes a main control unit 22 that performs overall control of the operation of the processing unit 12 itself, and a routing processing module 24 that functions as a module that enhances routing processing. In addition, the network processing unit 12 includes a connector according to a standard such as RJ-45 as an input / output port connected to the network 16, and for example, in this embodiment, packets can be transmitted and received via the two ports 26 and 28. .

  The routing processing module 24 includes a routing table 42 and an ARP table 44 for registering a routing entry and an ARP (Address Resolution Protocol) entry, respectively, and may be implemented by hardware.

  The module 24 can register similar entries in the tables 42 and 44 in response to an instruction from the processing unit 14 when a routing entry and an ARP entry are registered in the application processing unit 14.

  In addition, the routing processing module 24 has an ARP timer for each ARP entry registered in the ARP table 44. This ARP timer is the same ARP entry after the packet of the corresponding ARP entry is transmitted from the network processing unit 12. The N part ARP reception time until the network processing unit 12 receives this packet is measured. When the N part ARP reception time exceeds a predetermined ARP timeout time T2, the module 24 deletes the ARP entry from the ARP table 44. Further, the module 24 does not delete the routing entry in the routing table 42 according to the timeout time.

  Particularly in this embodiment, the network processing unit 12 is controlled by, for example, the main control unit 22 to determine whether or not the ARP reception time t1 has passed a predetermined provisional routing time T1, and to determine that it has elapsed Provisional routing can be performed. The provisional routing time T1 is a time for determining the provisional routing period of the received packet. In this provisional routing, when the ARP entry is not registered in the network processing unit 12, the registration in the application processing unit 14 is not confirmed. This is provisional routing.

  When executing the temporary routing, the network processing unit 12 temporarily transmits the received packet by routing, and simultaneously supplies the received packet to the application processing unit 14 to update the ARP timer. In the processing unit 12, a time shorter than the ARP timeout time T2 is set as the provisional routing time T1.

  In addition, the application processing unit (A unit) 14 performs routing control of a packet passed from the network processing unit 12 among the packets received by the device 10, and sends control information 102 to the network processing unit 12. Supply. For example, the application processing unit 14 issues an ARP request to know the destination of the received packet, receives an ARP response corresponding to the ARP request, and registers an entry related to the received packet.

  The application processing unit 14 of the present embodiment includes a main control unit 32 that performs overall control of the operation of the processing unit 14 itself, and a network processing module 34 that functions as a module that performs application processing such as routing control. .

  The network processing module 34 includes a routing table 52 and an ARP table 54 for registering routing entries and ARP entries, and may be implemented by software.

  This module 34 obtains the destination IP address (Internet Protocol address) from the received packet, issues an ARP request to know the MAC address (Media Access Control address) corresponding to this destination IP address, and An ARP response corresponding to the ARP request is received, and a destination MAC address can be obtained based on the ARP response.

  Further, the module 34 registers the ARP entry based on the IP address and the MAC address obtained in this way in the ARP table 54, and also detects the routing to the destination based on the IP address and the MAC address, and performs routing. It can be registered in the table 52.

  The network processing module 34 has an ARP timer for each ARP entry registered in the ARP table 54. This ARP timer is used for the same ARP entry after the packet of the corresponding ARP entry is transmitted from the application processing unit 14. The A part ARP reception time until the application processing unit 14 receives the packet is measured. When the A part ARP reception time elapses a predetermined ARP timeout time T3, the module 34 deletes the ARP entry from the ARP table 54. Further, the module 34 does not delete the routing entry in the routing table 52 according to the timeout time.

  In the packet processing apparatus 10 shown in FIG. 1, a dotted line 104 indicates the progress of packets and routing when an ARP entry is newly registered in the apparatus 10 or is registered after timeout is deleted. A dotted line 106 indicates the progress of the packet and the routing when the ARP entry already registered in the apparatus 10 arrives before the timeout.

  Next, the operation when the packet is received in the Gigabit Ethernet compatible router 10 in the present embodiment will be described with reference to the sequence charts of FIGS.

  First, the operation when the destination indicated by the packet received by the router 10 is not registered in the ARP tables 44 and 54 will be described with reference to the sequence chart of FIG.

  When a predetermined packet is sent to the router 10 in the network 16 (S202), the packet is supplied to the network processing unit 12 via the first port 26 (S204).

  The network processing unit 12 obtains a destination IP address from the received packet, and determines whether or not an ARP entry for the destination is registered in the ARP table 44 of the routing processing module 24 (S206). At this time, whether or not the routing entry is registered in the routing table 42 may also be determined.

  In this operation example, since it is determined in step S206 that no ARP entry has been registered, this packet is sent to the application processing unit 14 regardless of the N-part ARP reception time (S208).

  The application processing unit 14 also obtains the destination IP address from the received packet, and determines whether or not the ARP entry for this destination is registered in the ARP table 54 of the network processing module 34. Since it is not registered, an ARP request based on this IP address is issued in order to know the destination MAC address (S210).

  This ARP request is transmitted via the second port 28 (S212) and sent to the network 16 (S214).

  When an ARP response to the ARP request is sent from the destination, the ARP response is sent from the network 16 to the router 10 (S216).

  The ARP response is received via the second port 28, sent to the network processing unit 12 (S218), and further sent to the application processing unit 14 (S220).

  The application processing unit 14 obtains a destination MAC address based on the ARP response, creates an ARP entry based on the destination IP address and MAC address, and registers the ARP entry in the ARP table 54 of the network processing module 34 (S222). . At this time, an ARP timer corresponding to the registered ARP entry is created in the application processing unit 14, and its counting operation is started.

  The ARP entry is sent to the network processing unit 12, and the application processing unit 14 instructs the network processing unit 12 to register the ARP entry (S224). In this way, the ARP entry is registered in the ARP table 44 of the network processing unit 12 (S226). At this time, the network processing unit 12 also creates an ARP timer corresponding to the registered ARP entry and starts its counting operation.

  Further, in the application processing unit 14, a routing entry to the destination indicated by such an ARP entry is detected from the routing table 52 and sent to the network processing unit 12, and the application processing unit 14 sends it to the network processing unit 12. Registration of the routing entry is instructed (S228).

  If the routing entry of the destination cannot be detected from the routing table 52, the network processing module 34 newly generates an optimum routing to the destination and registers it as a routing entry in the routing table 52, and further generates the generated routing. The entry may be sent to the network processing unit 12 to instruct its registration.

  In this way, the routing entry is registered in the ARP table 44 of the network processing unit 12 (S230).

  When the ARP entry and the routing entry are registered in the network processing unit 12, the packet received by the router 10 is transmitted according to the registered routing. In this embodiment, the application processing unit 14 sends the network processing unit 12 (S232), transmitted via the second port 28 (S234), and sent to the network 16 toward the destination (S236).

  Next, the operation when the destination indicated by the packet received by the router 10 is registered in the ARP tables 44 and 54 will be described with reference to the sequence chart of FIG.

  Also in this operation example, a packet sent from the network 16 to the router 10 is supplied to the network processing unit 12 via the first port 26 in the same manner as steps S202 and S204 in the operation example shown in FIG. .

  Further, the network processing unit 12 determines whether or not the ARP entry for the destination of the received packet is registered in the ARP table 44 of the routing processing module 24 in the same manner as Step S206 of the operation example shown in FIG. Here, an already registered ARP entry is detected.

  Here, in the network processing unit 12, the subsequent processing differs according to the N-part ARP reception time of the received packet.

  For example, when the N-part ARP reception time of the received packet is before reaching the provisional routing time T1, the operation is performed as shown in the sequence chart of FIG.

  In this case, when the destination ARP entry of the received packet is detected from the ARP table 44 in step S206 and the routing entry indicating the routing to this destination can be detected from the routing table 42 of the routing processing module 24, the network processing unit 12 Then, the packet transmission according to this routing is executed and autonomous routing is performed. In this embodiment, the packet received by the router 10 is not sent to the application processing unit 14 and is sent to the second port 28. (S242) and sent to the network 16 toward the destination (S246).

  When the N-part ARP reception time of the received packet is after the provisional routing time T1 and before reaching the ARP timeout time T2, the operation is performed as shown in the sequence chart of FIG.

  Even in this case, in step S206, the destination ARP entry of the received packet is detected from the ARP table 44, and the routing entry to this destination is detected from the routing table 42 of the routing processing module 24. Particularly in the present embodiment, the network processing unit 12 performs packet transmission according to this routing to perform autonomous routing, and the received packet is sent to the application processing unit 14 to update the ARP timer. . That is, the network processing unit 12 performs provisional routing for this packet.

  When the network processor 12 performs autonomous routing of the packet, the packet received by the router 10 is transmitted from the network processor 12 through the second port 28 in the same manner as in steps S242 and S244 in FIG. (S252) and sent to the network 16 toward the destination (S254).

  When the received packet is sent to the application processing unit 14 for updating the ARP timer (S256), the application processing unit 14 reads the IP address from this packet, and the ARP entry corresponding to this IP address is stored in the ARP table. The ARP timer corresponding to this ARP entry is reset (S258).

  Further, registration of the ARP entry is instructed from the application processing unit 14 to the network processing unit 12 (S260). The network processing unit 12 determines whether or not the ARP entry related to the registration instruction matches the ARP entry related to the provisionally routed packet, and if it matches, the corresponding ARP timer is reset in the ARP table 44 (S262). ).

  In the network processing unit 12, even when a packet to be routed is sent from the application processing unit 14 (S264), the packet may be discarded because it has already been transmitted by provisional routing (S266).

  On the other hand, in the network processing unit 12, if the ARP entry related to the registration instruction and the ARP entry related to the provisional routing do not match, the packet related to the registration instruction has not been routed yet. Packets registered in the table 44 and sent from the application processing unit 14 are routed and transmitted.

  As described above, when the router 10 of this embodiment receives a packet in the provisional routing execution period from the provisional routing time T1 to the ARP timeout time T2, the network processing unit 12 autonomously transmits the routing, The application processing unit 14 registers the ARP entry again, and the network processing unit 12 initializes the ARP entry.

  If the N-part ARP reception time of the received packet is after the ARP timeout time T2, the ARP entry has been deleted from the ARP table 44 or 54. In order to newly register the ARP entry, FIG. It operates as shown in the sequence chart.

  The packet processing apparatus of the present invention is optimally used when synchronizing ARP entries in a system in which two or more MPU modules operate in cooperation with each other, as shown in the above embodiment. The present invention can also be used effectively when other information or data is synchronized between the above MPU modules.

It is a block diagram which shows one Example of the packet processing apparatus of this invention. 2 is a sequence chart for explaining an operation procedure when an unregistered packet is received in the packet processing apparatus shown in FIG. 1. 3 is a sequence chart for explaining an operation procedure when a registered packet is received outside the provisional routing execution period in the packet processing device shown in FIG. 1. 2 is a sequence chart for explaining an operation procedure when an already registered packet is received within a provisional routing execution period in the packet processing device shown in FIG. 1.

Explanation of symbols

10 Packet processing device
12 Network processing unit
14 Application processing section
16 network
22, 32 MPU
24 Routing processing module
26, 28 ports
34 Network processing module
42, 52 Routing table
44, 54 ARP table

Claims (4)

Network processing means with enhanced routing processing;
Including application processing means mainly performing application processing such as routing control,
The network processing unit and the application processing unit are respectively a main control unit that performs overall control of its own operation, an ARP table that stores ARP (Address Resolution Protocol) entries related to received packets, and a routing table that stores routing entries. And coordinating each entry between the network processing means and the application processing means,
Further, each of the network processing means and the application processing means can measure a reception time of a packet related to a predetermined ARP entry registered in the ARP table by an ARP timer and receive the packet before a predetermined timeout time elapses. If not, in the packet processing device for deleting the predetermined ARP entry from the ARP table,
The network processing unit sets a provisional routing time shorter than the predetermined timeout time in advance, and when receiving a packet related to the predetermined ARP entry registered in the ARP table, the network processing means If received before, the packet is autonomously routed, and if the packet is received after the provisional routing time elapses and before the predetermined timeout time elapses, The packet is autonomously routed, the packet is further sent to the application processing means to update the ARP timer, and when the packet is received after the predetermined time-out period, the packet is Sent to the application processing means to re-establish the predetermined ARP entry. Packet processing device, characterized by recording.   2. The packet processing device according to claim 1, wherein the device is a Gigabit Ethernet compatible router. A main control in which the network processing unit and the application processing unit collectively control their own operations, including a network processing unit with enhanced routing processing and an application processing unit that mainly performs application processing such as routing control. A packet processing device for coordinating each entry between the network processing unit and the application processing unit, and an ARP table for storing an ARP entry related to a received packet, and a routing table for storing a routing entry. In the packet processing method, the method includes:
For each of the network processing unit and the application processing unit, the reception time of a packet related to a predetermined ARP entry registered in the ARP table was measured by an ARP timer, and could not be received until a predetermined timeout time passed A first step of deleting the predetermined ARP entry from the ARP table;
The network processing unit sets a provisional routing time shorter than the predetermined timeout time in advance, and when receiving a packet related to a predetermined ARP entry registered in the ARP table, a routing corresponding to the reception time A second step of performing processing,
The second step is a third step of autonomously routing the packet when the packet is received before the provisional routing time elapses;
If the packet is received after the provisional routing time has elapsed and before the predetermined timeout time has elapsed, the packet is provisionally routed autonomously, and the packet is further transmitted to the application processing unit. A fourth step of sending to the ARP timer to update,
And a fifth step of re-registering the predetermined ARP entry by sending the packet to the application processing unit when the packet is received after the predetermined time-out period has elapsed. Processing method. 2. The packet processing method according to claim 1, wherein the packet processing device is a Gigabit Ethernet compatible router.

Images