TWI756444B - Network interface cards, fabric cards, and line cards for loop avoidance in a chassis switch - Google Patents

Abstract

A network interface card disposed in a chassis switch, which includes a switch device and a controller, is provided. The switch device includes a plurality of port connected to a plurality of other network interface cards in the chassis switch. When the network interface card is a fabric card, the controller sets the ports to a forwarding state and sends a first control packet through each of the ports. In response to the network interface card being a root fabric card, the controller receives a plurality of second control packets from a plurality of line cards through the ports and determines one of the line cards as a designated line card according to a plurality of second IDs included in the second control packets. In response to the network interface card being a backup fabric card, the controller sets the ports other than the one connected to the designated line card to a listening state.

Description

Network interface cards, switch cards, and line cards that avoid loops in box switches

The present application mainly relates to a path planning technology between a plurality of network interface cards, and particularly relates to a network interface card, a switch card, and a line card that can avoid the formation of loops in a box-type switch.

With the rapid development of network technology, people's demand for network bandwidth has not only begun to increase year by year, but also the demand for network environment has also changed from time to time. Therefore, the establishment of network environment needs to consider dynamic and simple make adjustments.

Since the switch chassis can selectively carry different communication components, such as one or more network interfaces, depending on the requirements of different network environments. Therefore, box switches are widely used in the installation of network environments, and because box switches usually contain multiple network interface cards, the need to manage these network interface cards is derived, usually by sending control packets. way to manage the network interface card.

FIG. 1 is a schematic diagram showing a transmission path of control packets between various network interface cards in a conventional box-type switch. Generally speaking, each network interface card in the box switch can be a switch card (Fabric card) or a line card (Line card). Taking Fig. 1 as an example, each switch card and each line card are connected in communication, so that they can transmit control packets to each other to achieve the purpose of management. However, since any switch card and any line card are connected to each other for communication, the transmission path of the control packet is likely to form a loop. To be more specific, if the management among these network interface cards is carried out by means of multicast (Multicast) to transmit control packets to achieve the purpose of management, loops are likely to be formed on the transmission path, and the loops will further cause broadcast storms. Broadcast storms will not only cause traffic jams between network interface cards, but also exhaust the resources of each network interface card due to the repeated transmission of control packets, which seriously affects the management performance of the box switch. .

In addition, if the transmission path planning of control packets is carried out in order to avoid the formation of loops, it is not conducive to transmission due to the dynamic change characteristics of each network interface card in the box switch (such as changes in insertion or removal of network interface cards, failures, etc.). For path planning, if the transmission path is planned by monitoring the change status of each network interface card, the additional use of controller monitoring will not only increase the construction cost of the box switch, but also affect its performance.

The present application proposes a network interface card, switch card, and line card that avoids forming loops in a box-type switch, in addition to avoiding loops in the packet transmission path in the box-type switch, it can also adapt to the network Various state changes of the interface card adaptively complete the path planning to avoid loop formation.

An embodiment of the present application provides a network interface card, which can be installed in a box-type switch. The above-mentioned network interface card includes a switching device and a controller. The switching device has a plurality of ports, wherein the ports are connected to a plurality of other network interface cards in the box-type switch, and each of the other network interface cards is a switch card or a line card. When the network interface card is a switch card, the controller executes the following steps: setting the ports to a forwarding state and transmitting a first control packet through each of the ports. Set as a root switch card and receive a plurality of second control packets from a plurality of line cards through the above-mentioned port, and determine one of the above-mentioned line cards according to the plurality of second identification codes included in the above-mentioned second control packets. Designating a line card, and setting the ports other than those connected to the designated line card to a listening state in response to the network interface card being set as a backup switch card. In addition, when the network interface card is a line card, the controller further performs the following steps: setting the port to the listening state and receiving the first control packet from each of the plurality of switching cards through the port, According to the plurality of first identification codes included in the first control packet, one of the above-mentioned exchange cards is determined as the above-mentioned source exchange card, and the remaining ones of the above-mentioned exchange cards are determined as one or more backup exchange cards, and according to the above-mentioned network interface The card is the designated line card and sets the port to the forwarding state.

Another embodiment of the present application provides a switch card, which can be installed in a box-type switch. The above-mentioned switch card includes a switch device and a controller. The switching device has a plurality of ports, wherein the ports are connected to a plurality of line cards in the box-type switch. The controller is used for setting the ports to a forwarding state and transmitting a first control packet including a first identification code through each of the ports, in response to receiving a message from the line card through the port within a time interval. A plurality of second control packets are executed to perform the following steps: determining one of the line cards as a designated line card according to the plurality of second identification codes included in the second control packets, and transmitting a third control packet through each of the ports , wherein the third control packet includes the information of the designated line card and the switch card being a source switch card.

Yet another embodiment of the present application provides a line card, which can be installed in a box-type switch. The above-mentioned line card includes a switching device and a controller. The switching device has a plurality of ports, wherein the ports are connected to a plurality of switching cards in the box-type switch. The above-mentioned controller is used for setting the above-mentioned port to a listening state and receiving a plurality of first control packets from the above-mentioned switching card through the above-mentioned port, and determining the above-mentioned switching card according to the plurality of first identification codes included in the above-mentioned first control packet. One is a source switch card, and one of the ports connected to the source switch card is set to a forwarding state to transmit a second control packet including a second identification code.

Regarding other additional features and advantages of the present application, those skilled in the art, without departing from the spirit and scope of the present application, can make use of the network interface cards, switch cards, and line cards disclosed in the implementation method of the present application. Obtained with a few alterations and refinements.

100‧‧‧Box Switch

11~14‧‧‧Exchange Card

21~28‧‧‧Line Card

310, 410‧‧‧Controller

320, 420‧‧‧ storage device

330, 430‧‧‧Switch

340-1~340-8, 440-1~440-4‧‧‧Port

S501~S522‧‧‧Step No.

FIG. 1 is a schematic diagram showing a transmission path of control packets between various network interface cards in a conventional box-type switch.

FIG. 2 is a schematic diagram of a control packet transmission path between a plurality of network interface cards in a box-type switch according to an embodiment of the present application.

FIG. 3 is a schematic diagram of an exchange card according to the embodiment of FIG. 2 .

FIG. 4 is a schematic diagram of a line card according to the embodiment of FIG. 2 .

FIGS. 5A to 5D are flowcharts of a method for avoiding broadcast storms according to an embodiment of the present application.

What is described in this chapter is the best way to implement the application, the purpose is to illustrate the spirit of the application but not to limit the scope of protection of the application. "" is used to indicate the existence of specific technical features, values, method steps, operation processes, elements and/or components, but does not exclude the possibility of adding more technical features, values, method steps, operation processes, elements , components, or any combination of the above.

FIG. 2 is a schematic diagram of a control packet transmission path between a plurality of network interface cards in a box-type switch according to an embodiment of the present application. The box-type switch 100 includes a plurality of network interface cards, wherein each network interface card can be a switch card or a line card.

Generally speaking, the box-type switch 100 can provide the flexibility of the network structure for the local area network. Through the configuration of the network interface card inside the box-type switch 100, it can dynamically adapt to the change of the network structure of the local area network. Accommodates more or fewer network termination devices. For example, the local area network can be a network constructed by Ethernet, Wireless Fidelity (WiFi) network, Twisted Pair network, or Coaxial cable network, etc. A road, also known as an intranet, usually covers a local area, such as an office, or a certain floor in a building. Each network interface card (such as a line card) in the box switch 100 can be further coupled to a network terminal device, such as a notebook computer, a desktop computer, a smart phone, a tablet computer, workstation, or server, etc.

For the convenience of description, in this embodiment, the box-type switch 100 includes 4 switching cards 11-14 and 8 line cards 21-28, wherein each switching card is connected to all the line cards, but not connected with other Switch cards are connected, and likewise, each line card is connected to all switch cards, but not to other line cards. However, it should be noted that the number of network interface cards shown in FIG. 2 is only for providing an illustrative example, and is not intended to limit the protection scope of this application. That is, the number of switch cards included in the box-type switch 100 may be less than or more than 4, and the number of line cards may be less than or more than 8.

Although not shown, the box-type switch 100 has a plurality of slots, and each slot can be accessed by a network interface card. Specifically, the slot can be further subdivided into a switch card slot and a line card slot, which are respectively used for the access of the switch card and the line card. In particular, each network interface card is configured with a respective identification code according to its slot position, and the identification code can be used for management among the network interface cards.

It is worth noting that, when managing these network interface cards in this embodiment, in order to avoid the occurrence of broadcast storms, each network interface card will perform corresponding actions according to its card type (for example, a switch card or a line card). To complete the control packet transmission path planning between network interface cards. As shown in Figure 2, the result of the path planning will obtain one of the switching cards 11 to 14 (eg, switching card 11) as the root switching card, and the other switching cards are backup switching cards; in addition, , one of the line cards 21 to 28 (eg, the line card 21 ) is a designated (designated) line card, and the other switch cards are backup line cards. In addition, only the source switch card (eg: switch card 11) can set the ports connected to all line cards to the forwarding state, and only the designated line card (eg: line card 21) can switch the ports connected to all switch cards to the forwarding state. The port is set to the forwarding state, and the backup switch card and the backup line card must set the ports connected to each other to the listening state, so that no transmission operation can be performed between the backup switch card and the backup line card (that is, the second The crossed line in the figure) prevents the transmission path from forming a loop and causing a broadcast storm.

FIG. 3 is a schematic diagram of an exchange card according to the embodiment of FIG. 2 . In this embodiment, the box-type switch 100 includes 4 switching cards and 8 line cards, wherein the hardware structure of each switching card is shown in FIG. 3 , including a controller 310 , a storage device 320 , a switching device 330 , and Port 340-1~340-8.

The controller 310 can be a general-purpose processor, a central processing unit (CPU), a micro control unit (MCU), an application processor (AP), or a digital signal processor (Digital Signal Processor). , DSP), etc., which may include various circuit logics to provide data processing and operation functions, read or write instructions/codes and data from the storage device 320, control the operation of the switching device 330 to execute control packets. Send and receive operations, and control the status settings of ports 340-1 to 340-8.

In particular, the controller 310 is used for coordinating the operations of the storage device 320, the switching device 330, and the ports 340-1 to 340-8, so as to implement the method for avoiding broadcast storms of the present application.

It should be understood by those skilled in the art that the circuit logic in the controller 310 may generally include a plurality of transistors to control the operation of the circuit logic to provide required functions and operations. Furthermore, the specific structure of the transistor and the connection relationship between them are usually determined by the compiler. For example, the Register Transfer Language (RTL) compiler can be operated by the processor, which is similar to the assembly language. A script of code is compiled into a form suitable for designing or manufacturing the circuit logic.

The storage device 320 may be random access memory (RAM), flash memory, cache memory, or other types of memory, or other storage media for storing the machine Readable instructions or code (eg, the code of the method for avoiding broadcast storms of the present application), and data, such as the management record (record) of each network interface card.

The switching device 330 is used for receiving the control signal from the controller 310 to set the forwarding/listening state of the ports 340-1 to 340-8, and to transmit and receive control packets through the ports 340-1 to 340-8, and also That is, the main function of the switching device 330 is to process the switching of control packets for the purpose of managing the network interface card. In one embodiment, the switch device 330 may be a (Gibabit) Ethernet switch conforming to standard specifications such as IEEE 802.3, 802.3u, 802.3ab, and 802.3x.

The ports 340-1 to 340-8 are respectively used to be coupled to all the line cards 21 to 28 in the box switch 100, and to transmit/forward control packets to the line cards 21 to 28, and/or receiving control packets from line cards 21-28.

It should be understood that the elements shown in FIG. 3 are only used to provide an illustrative example, and are not used to limit the protection scope of the present application. For example, the switch card may further include another switch device for processing data packet transfer operations, which is different from the switch device 330 ; or, the number of ports included in the switch card may be in accordance with the actual lines in the box-type switch 100 . The number of cards is adjusted accordingly.

FIG. 4 is a schematic diagram of a line card according to the embodiment of FIG. 2. FIG. In this embodiment, the box-type switch 100 includes four switching cards 11-14 and eight line cards 21-28, wherein the hardware structure of each line card is as shown in FIG. 4, including a controller 410 and a storage device 420 , the switching device 430, and the ports 440-1 to 440-4.

The controller 410 can be a general-purpose processor, a central processing unit, a microprocessor, an application processor, or a digital signal processor. Read or write commands/codes and data, control the switching device 430 to perform the transmission and reception of control packets, and control the status settings of the ports 440-1 to 440-4.

In particular, the controller 410 is used for coordinating the operations of the storage device 420, the switching device 430, and the ports 440-1 to 440-4, so as to implement the method for avoiding broadcast storms of the present application.

It should be understood by those skilled in the art that the circuit logic in the controller 410 may generally include a plurality of transistors to control the operation of the circuit logic to provide required functions and operations. Furthermore, the specific structure of the transistor and the connection relationship between them are usually determined by the compiler. For example, the register transfer language compiler can be operated by the processor to compile the instruction file similar to the assembly language code into suitable in the form required to design or manufacture the logic of the circuit.

The storage device 420 may be random access memory, flash memory, cache memory, or other types of memory, or other storage media for storing machine-readable instructions or code (eg, this application the code for methods to avoid broadcast storms), and data such as each network interface card's own management record.

The switching device 430 is used for receiving the control signal from the controller 410 to set the forwarding/listening state of the ports 440-1 to 440-4, and to transmit and receive control packets through the ports 440-1 to 440-4, and also That is, the main function of the switching device 430 is to process the switching of control packets for the purpose of managing the network interface card. In one embodiment, the switching device 430 may be a (Gigabit) Ethernet switch conforming to standard specifications such as IEEE 802.3, 802.3u, 802.3ab, and 802.3x.

The internal ports 440-1 to 440-4 are respectively used to be coupled to all the switch cards 11 to 14 in the box switch 100, and transmit/forward control packets to the switch card 11 according to the set forwarding/listening state. ~14, and/or receiving control packets from the switch cards 11~14.

It should be understood that the elements shown in FIG. 4 are only used to provide an illustrative example, and are not used to limit the protection scope of the present application. For example, the line card may further include another switching device for processing data packet forwarding, and its function is different from that of the switching device 430; The number of swap cards is adjusted accordingly.

FIGS. 5A to 5D are flowcharts of a method for avoiding loop formation according to an embodiment of the present application. In this embodiment, the method of avoiding the formation of loops can be applied to any network interface card (eg, switch card or line card) in the box-type switch.

First, the network interface card determines the configured identification code according to its slot position (step S501 ), and then determines whether the card is a switch card or a line card (step S502 ).

Following step S502, when the network interface card is a switch card, all ports are set to the forwarding state (step S503). Specifically, when a port is set to the forwarding state, it means that a network interface card (such as a switch card or a line card) can transmit and receive operations through this port, such as sending/forwarding control packets to other NIC, or receive control packets from other NICs. Next, the exchange card transmits a first control packet including the identification code of the network interface card through each port and starts timing a period of time (step S504 ). In one embodiment, the first control packet may be a bridge protocol data unit (Bridge Protocol Data Unit, BPDU).

Continuing with step S502, when the network interface card is a line card, all ports are set to the listening state and a period of time is started (step S505). Specifically, when a port is set to the listening state, it means that the network interface card (such as a switch card or line card) is not allowed to transmit through the port, but can only receive through the port. Operation. Next, the line card checks whether the above-mentioned first control packet is received through any port (step S506 ). The identification code carried in the first control packet replaces the source exchange card identification code in the management record (step S507). In other words, in this embodiment, the switch card corresponding to the smallest of the identification codes carried by all the first control packets is used as the source switch card. However, in another embodiment, the switch card corresponding to the largest one of the identification codes carried in all the first control packets may be the source switch card.

In one embodiment, each network interface card stores its own management record, which includes: the identification code of the source switch card, the identification code of the designated line card, and its own identification code.

Continuing with the "No" branch of step S506 and step S507, the line card further checks whether the time interval has expired (step S508). The card has received the first control packet from all switch cards within the time interval. Therefore, the line card can determine which switch card is the root switch card according to the management record currently stored, and will connect to the root switch card. The port of the switch card is set to the forwarding state (step S509 ), and then a second control packet including its own identification code and management record is transmitted through the port connected to the source switch card (step S510 ).

Continue to step S504, after the switch card transmits the first control packet, it checks whether the second control packet is received through any port (step S511). When the identification code carried in the packet is smaller than the designated line card identification code in the management record of the switching card, the identification code carried in the second control packet is used to replace the designated line card identification code in the management record of the switching card ( Step S512). In other words, in this embodiment, the line card corresponding to the smallest of the identification codes carried by all the second control packets is used as the designated line card. However, in another embodiment, the line card corresponding to the largest one of the identification codes carried by all the second control packets may be the designated line card.

Continuing the "No" branch of step S511 and step S512, the exchange card further checks whether the time interval has expired (step S513). The card has received the second control packet from all line cards within the timed interval. Next, it is judged whether the switch card is the source switch card according to whether the second control packet has been received (step S514 ), and if so, which line card is determined as the designated line card according to the management record stored therein (step S515 ) , and then transmit a third control packet including the information of the source switch card and the designated line card through each port (step S516 ).

Following step S510, after transmitting the second control packet, the line card receives the above-mentioned third control packet (step S517), and then determines whether it is a designated line card or a backup line card according to the information carried in the third control packet (step S518) .

Continue to step S518, when it is determined to be the designated line card, the line card will set all ports to the forwarding state, and forward the third control packet through each port other than the source switch card (step S519), and the process ends .

Following step S518, when it is determined to be the backup line card, the line card will discard the third control packet and not forward it (step S520), and the process ends.

Following step S514, when the switch card is not the source switch card, it waits to receive the third control packet forwarded by the designated line card (step S521). Specifically, when the switch card receives the forwarded third control packet , it is possible to confirm which switching card is the source switching card and which line card is the designated line card according to the third control packet, and at the same time it is determined that it is the backup switching card. After that, the backup switch card sets all ports except those connected to the designated line card to the listening state (step S522 ), and the process ends.

According to the foregoing embodiments, the embodiments of the present invention perform path planning by executing a specific process, so that the transmission path of the control packet avoids forming loops, thereby improving the resource utilization efficiency of the network interface card, and at the same time improving the box shape. Switch management efficiency. In addition, it is worth noting that the embodiment of the present invention can effectively complete the planning of the control packet transmission path in response to the state change of the network interface card in the box-type switch, and it can be adaptively carried out without additional monitoring of the network interface card change. The planning of the packet transmission path, so no additional construction cost is required.

Although various embodiments are disclosed as above in this application, they are only for reference and are not used to limit the scope of this application. Anyone who is familiar with the art can make some changes without departing from the spirit and scope of this application. with retouch. Therefore, the above embodiments are not intended to limit the scope of the present application, and the protection scope of the present application should be determined by the scope of the appended patent application.

Words such as "first", "second" and "third" used in the scope of the patent application are used to modify the elements in the claims, and are not used to indicate that there is a priority order, an antecedent relationship between them, or The precedence of one element over another, or the chronological order in which method steps are performed, is only used to distinguish elements with the same name.

100‧‧‧Box Switch

11~14‧‧‧Exchange Card

21~28‧‧‧Line Card

Claims (16)

A network interface card, which can be set in a chassis switch, includes: a switching device having a plurality of ports, wherein the ports are connected to a plurality of other network interface cards in the chassis switch, Each of the above-mentioned other network interface cards is a switch card or a line card; and a controller for performing the following steps when the above-mentioned network interface card is a switch card (fabric card): setting the above-mentioned ports is in a forwarding state and transmits a first control packet through each of the above-mentioned ports, in response to the above-mentioned network interface card being a root switch card, and receives the data from a plurality of line cards through the above-mentioned ports through the above-mentioned ports. A plurality of second control packets, and according to the plurality of second identification codes included in the second control packets, one of the line cards is determined as a designated (designated) line card, and the network interface card is a backup switch card according to the Setting the ports other than those connected to the designated line card to a listening state; wherein the controller is further configured to perform the following steps when the network interface card is a line card: set the port to a listening state. In the listening state, the first control packet is received from each of the plurality of switch cards through the port, and one of the switch cards is determined as the source switch card according to the plurality of first identification codes included in the first control packet. , and set the port to the forwarding state according to the network interface card being the designated line card. The network interface card as described in claim 1, wherein the controller is further configured to determine the remaining ones of the line cards according to the second identification code according to the network interface card is the root switch card as one or multiple backup (backup) a line card, and when the network interface card is a line card, according to the first identification code, it is determined that the rest of the exchange cards are one or more backup exchange cards. The network interface card described in claim 1, wherein the controller is further configured to, when the network interface card is a switch card, further execute the following steps: according to the network interface card being the root switch card A third control packet is transmitted through each of the above-mentioned ports, and the above-mentioned third control packet includes the information of the above-mentioned source switch card and the above-mentioned designated line card. The network interface card of claim 3, wherein the controller is further configured to, when the network interface card is a line card, further perform the following steps: connecting the port to one of the root switch cards is set to the above-mentioned forwarding state to transmit the above-mentioned second control packet, and the above-mentioned third control packet is received through the above-mentioned port. Since the above-mentioned network interface card is the above-mentioned designated line card, after the above-mentioned port is set to the above-mentioned forwarding state, each The port forwards the third control packet. The network interface card as described in item 1 of the claimed scope, wherein the second control packet further includes a record for storing the smallest or the largest of the first identification codes, and the controller uses the first identification code One of the above-mentioned exchange cards corresponding to the smallest or the largest of the codes is the above-mentioned source exchange card. The network interface card according to claim 1, wherein the controller uses one of the line cards corresponding to the smallest or largest of the second identification codes as the designated line card. A switch card, which can be set in a box-type switch, includes: a switching device having a plurality of ports, wherein the ports are connected to a plurality of line cards in the box switch; and a controller for setting the ports to a forwarding state and passing through each of the ports The port transmission includes a first control packet with a first identification code. In response to receiving a plurality of second control packets from the line card through the port within a time interval, the following steps are performed: according to the second control packet included in the second control packet. A plurality of second identification codes determine one of the line cards as a designated line card, and transmit a third control packet through each of the ports, wherein the third control packet includes the designated line card and the switch card as a source Exchange card information. The switching card as described in claim 7, wherein the controller is further configured to determine the second identification code according to the second identification code in response to receiving the second control packet from the line card through the port within the time interval The remainder of the line cards are one or more backup line cards. The switch card as described in claim 7, wherein the controller is further configured to perform the following step in response to not receiving the second control packet through the port within the time interval: receiving the line through the port The third control packet forwarded by the card determines that the switch card is a backup switch card according to the third control packet, and sets the ports other than those connected to the designated line card to a listening state. The switch card according to claim 7, wherein the controller uses one of the line cards corresponding to the smallest or largest of the second identification codes as the designated line card. A line card, which can be set in a box-type switch, includes: a switching device having a plurality of ports, wherein the ports are connected to a plurality of switching cards in the box-type switch; and a controller for setting the ports to a listening state and transferring the data from the switching cards through the ports Receive a plurality of first control packets, determine one of the above-mentioned switch cards as a source switch card according to the plurality of first identification codes included in the first control packets, and set one of the ports connected to one of the above-mentioned source switch cards In a forwarding state, a second control packet including a second identifier is transmitted. The line card according to claim 11, wherein the controller is further configured to determine the remaining exchange cards as one or more backup exchange cards according to the first identification code. The line card of claim 11, wherein the controller is further configured to receive a third control packet including the information of the source switch card and a designated line card from the source switch card through the port, and According to the third control packet, it is determined that the line card is the designated line card or a backup line card. The line card of claim 13, wherein the controller is further configured to, when the line card is the designated line card, set all ports to the forwarding state, and connect to the source switch card through Each of the above-mentioned ports other than the above-mentioned port forwards the above-mentioned third control packet. The line card of claim 13, wherein the controller is further configured to discard the third control packet when the line card is the backup line card. The line card as described in claim 11, wherein the controller is a One of the above-mentioned exchange cards corresponding to the smallest or largest of the above-mentioned first identification codes is the above-mentioned source exchange card.

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