JP2015170974A - relay device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chassis type relay device capable of reducing a communication load inside the device.SOLUTION: In a first outer port (P[3, 1]) of a first line card (LC[3]) that serves as one of ingress side line cards and a second outer port (P[4, 1]) of a second line card (LC[4]) that serves as the other are set link aggregation groups (LAG[1]). The ingress side line card (LC[1]), when relaying a frame FL1 received at a predetermined outer port to a first network domain to which a first and a second outer ports belong by multi cast or broad cast, relays the frame only to either one of the first line card and the second line card.

Description

  The present invention relates to a chassis-type relay device, for example, a relay device in which a link aggregation group is set across line cards.

  For example, in Patent Literature 1, an IF-MGID table is provided in an interface (IF) card to reduce resources and processing load related to management of a plurality of grouped ports, and an SW in a switch (SW) card. A configuration example provided with an MGID table is shown. Correspondence between multi-group ID (MGID) and each port in the IF card is set in the IF-MGID table, and correspondence between MGID and each IF card is set in the SW-MGID table. .

  In Patent Document 2, it is assumed that a link aggregation group is set across a plurality of line units and different links are used for transmission and reception, and various types for preventing flooding that occurs in this case A configuration with means is shown. Further, in this configuration, each line card includes a flooding setting table that determines whether or not transmission to each port is necessary in order to determine an output port when flooding occurs. In the table, any one of the ports in which the link aggregation group is set is set to be sent.

JP2013-128250A JP 2008-79043 A

  A relay device called a chassis type in which a plurality of line cards are mounted in one housing is known. In such a relay device, for example, a link aggregation group (hereinafter abbreviated as LAG) may be set across the line cards between the ports of the two line cards. A port group in which LAG is set is logically regarded as one port, and a frame passing through the one logical port is appropriately distributed to each port constituting the logical port.

  The relay device relays a multicast or broadcast frame. Here, when the destination port of the frame includes a LAG set across the line cards, the frame is relayed from the receiving side line card to the transmitting side line card where the LAG is set. The The frame relay between the line cards is performed by a backplane having a mesh-like wiring or a switch card for switching between the line cards.

  The backplane and the switch card are required to have a wide communication band because all frames associated with communication between the plurality of line cards and the outside of the apparatus are aggregated. However, it is becoming increasingly difficult to secure a sufficient communication band as the speed of the relay device increases and the scale increases. In particular, the relay of frames such as multicast as described above places a large communication load on the backplane and the switch card. Therefore, it is desirable to reduce such a communication load.

  The present invention has been made in view of the above, and one of its purposes is to provide a chassis type relay device capable of reducing the communication load inside the device.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of a typical embodiment will be briefly described as follows.

  The relay device according to the present embodiment includes a plurality of line cards each having a single or a plurality of external ports. The plurality of line cards include an ingress side line card that relays a frame received at a predetermined external port to another line card, and an egress side line card that transmits a frame relayed from the ingress side line card from a predetermined external port. Have. The first line card that is one of the egress side line cards includes a first external port, and the second line card that is any other of the egress side line cards includes a second external port. A link aggregation group is set for the first external port and the second external port. When the ingress side line card relays a frame received at a predetermined external port to the first network domain to which the first external port and the second external port belong by multicast or broadcast, the ingress side line card transmits the frame to the first line card and the second line card. Relay to only one of the line cards.

  The effects obtained by the representative embodiments of the invention disclosed in the present application will be briefly described. In the chassis type relay device, the communication load inside the device can be reduced.

In the relay apparatus by Embodiment 1 of this invention, it is the schematic which shows the structural example and the operation example. FIG. 2 is a schematic diagram illustrating an operation example different from that in FIG. 1 in the relay device of FIG. 1. FIG. 2 is a block diagram illustrating a configuration example of the line card in the relay device of FIG. 1. (A) is a figure which shows the structural example of the address table in FIG. 3, (b) is a figure which shows the structural example of the LAG table in FIG. 3, (c) is a structure of the port table in FIG. It is a figure which shows an example. FIG. 4 is an explanatory diagram illustrating a schematic operation example at the time of unicast relay in the relay device including the line card of FIG. FIG. 4 is an explanatory diagram illustrating a schematic operation example at the time of multicast or broadcast relay in the relay device including the line card of FIG. 3. (A) is the schematic which shows the structural example in the relay apparatus by Embodiment 2 of this invention, (b) is the schematic which shows the structural example of the relay system to which the relay apparatus of (a) is applied. It is. It is the schematic which shows the structural example and operation example of a relay apparatus examined as a comparative example of FIG.

  In the following embodiment, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not irrelevant, and one is the other. Some or all of the modifications, details, supplementary explanations, and the like are related. Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), especially when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and may be more or less than the specific number.

  Further, in the following embodiments, the constituent elements (including element steps and the like) are not necessarily indispensable unless otherwise specified and apparently essential in principle. Needless to say. Similarly, in the following embodiments, when referring to the shapes, positional relationships, etc. of the components, etc., the shapes are substantially the same unless otherwise specified, or otherwise apparent in principle. And the like are included. The same applies to the above numerical values and ranges.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

(Embodiment 1)
<< Schematic configuration of relay device (this embodiment) >>
FIG. 1 is a schematic diagram illustrating a configuration example and an operation example of the relay device according to the first embodiment of the present invention. The relay device shown in FIG. 1 includes a plurality of (four in this case) line cards LC [1] to LC [4] and a plurality of line cards LC [1] to LC [4] in one casing. This is a chassis-type switch device equipped with a backplane 10 that bears the relay. Hereinafter, each of the plurality of line cards LC [1] to LC [4] is representatively referred to as a line card LC. The relay device corresponds to, for example, an L2 switch that performs layer 2 relay processing based on OSI (Open Systems Interconnection), an L3 switch that performs layer 3 relay processing, or the like. Here, for convenience, the case where the relay device is an L2 switch will be described as an example.

  Although illustration is omitted, the backplane 10 is constituted by, for example, a wiring board on which a plurality of card slots are mounted, and a plurality of line cards LC are mounted in the plurality of card slots, respectively. Although illustration is omitted, actually, a management card or the like for managing a plurality of line cards LC is mounted in the plurality of card slots. The backplane 10 includes a communication line 16 that connects a plurality of line cards LC in a mesh shape through a plurality of card slots.

  Here, a system in which relaying between a plurality of line cards LC is performed through the backplane 10 is taken as an example, but instead, a system in which switching is performed through a switch card may be used. In this case, a switch card is mounted in the plurality of card slots described above, and the backplane includes communication lines that connect the switch card and the plurality of line cards LC, respectively.

  The plurality of line cards LC include an ingress line card that relays a frame received at a predetermined external port to another line card LC or its own external port, and a frame relayed from the ingress side line card to a predetermined external port. Egress line card transmitting from the port. In the example of FIG. 1, the ingress side line card corresponds to the line card LC [1], and the egress side line card corresponds to the line cards LC [2] to LC [4]. Here, for convenience of explanation, the ingress side line card and the egress side line card are separated, but in reality, each of the plurality of line cards LC is assigned to the ingress side line card according to the direction of communication. Can also be an egress line card.

  The line card LC [1] includes a plurality of external ports P [1,1], P [1,2], an LC table processing unit 12a, and an LC table (card table) 13a. A plurality of P [1,1] and P [1,2] are each connected to the outside of the apparatus via a communication line (specifically, an Ethernet (registered trademark) line) 11, and a frame is formed between the outside of the apparatus. Communication (specifically, Ethernet frame) is performed. In the example of FIG. 1, the external port P [1,1] is set to a network domain (ie, broadcast domain) with a VLAN (Virtual Local Area Network) identifier (VID) = 1, and the external port P [1,2] Is set in the network domain of VLAN identifier (VID) = 2.

  The LC table (card table) 13a is a table for multicast (hereinafter abbreviated as MC) or broadcast (hereinafter abbreviated as BC), and includes a network domain and a destination line card LC corresponding to the network domain. Keep the relationship. When the LC table processing unit 12a relays the MC or BC frame to another line card, the LC table processing unit 12a relays the frame to the destination line card LC determined based on the LC table 13a.

  The line card LC [2] includes a plurality of external ports P [2,1], P [2,2], a port table processing unit 14b, and a port table 15b. A plurality of external ports P [2,1] and P [2,2] transmit or receive frames to / from the outside of the apparatus, as in the case of the line card LC [1]. In the example of FIG. 1, the external port P [2,1] is set to the network domain with VLAN identifier (VID) = 1, and the external port P [2,2] is the network domain with VLAN identifier (VID) = 2. Set to

  The port table 15b is a table for MC or BC, and holds the relationship between the network domain and the external port of its own destination corresponding to the network domain. When the MC or BC frame is relayed from the ingress side line card, the port table processing unit 14b relays the frame to the destination external port determined based on the port table 15b. Further, the port table processing unit 14b relays the MC or BC frame received at its predetermined external port to its predetermined external port excluding the received external port (that is, at the ingress side line card). Also when operating), the frame is relayed to the external port of the destination determined based on the port table 15b.

  The line card LC [3] includes an external port P [3, 1], a port table processing unit 14c, and a port table 15c. The external port P [3, 1] transmits / receives a frame to / from the outside of the apparatus as in the case of the line card LC [1]. In the example of FIG. 1, the external port P [3, 1] is set to the network domain with VLAN identifier (VID) = 1. The port table processing unit 14c and the port table 15c have the same functions as the port table processing unit 14b and the port table 15b of the line card LC [2].

  The line card LC [4] includes a plurality of external ports P [4, 1], P [4, 2], P [4, 3], a port table processing unit 14d, and a port table 15d. A plurality of external ports P [4,1], P [4,2], and P [4,3] transmit or receive frames to / from the outside of the apparatus as in the case of the line card LC [1]. Do. In the example of FIG. 1, the external port P [4, 1] is set in the network domain with VLAN identifier (VID) = 1. The external ports P [4,2] and P [4,3] are set in the network domain with VLAN identifier (VID) = 2. The port table processing unit 14d and the port table 15d have the same functions as the port table processing unit 14b and the port table 15b of the line card LC [2].

  Here, in the example of FIG. 1, the external port (first external port) P [3, 1] of the line card (first line card) LC [3] to be the egress side line card and the egress side line card. LAG (LAG [1]) is set in the external port (second external port) P [4, 1] of the line card (second line card) LC [4]. That is, LAG is set across the line cards LC. Also, the external port (third external port) P [4, 2] and the external port (fourth external port) P [4, 3] of the line card (third line card) LC [4] serving as the egress side card. Is set to LAG (LAG [2]).

  The LC table 13a of the line card LC [1] holds the line cards LC [2] and LC [3] as destination line cards corresponding to the network domain (first network domain) with VLAN identifier (VID) = 1. . That is, the LC table 13a holds the line card (first line card) LC [3] corresponding to one of the LAG [1] as the destination line card, but the line corresponding to the other of the LAG [1]. The card (second line card) LC [4] is not held. The LC table 13a holds line cards LC [2] and LC [4] as destination line cards corresponding to the network domain (second network domain) with VLAN identifier (VID) = 2.

  The port table 15b of the line card LC [2] holds the external port P [2,1] as a destination external port corresponding to the network domain of VLAN identifier (VID) = 1, and VLAN identifier (VID) = 2. The external port P [2, 2] is held as a destination external port corresponding to the network domain. The port table 15c of the line card (first line card) LC [3] has an external port (first external port) as a destination external port corresponding to the network domain (first network domain) with VLAN identifier (VID) = 1. Hold P [3,1].

  The port table 15d of the line card (second line card or third line card) LC [4] has an external port as a destination external port corresponding to the network domain (first network domain) with VLAN identifier (VID) = 1. (Second external port) Holds nothing including P [4, 1]. The port table 15d includes external ports (third and fourth external ports) P [4, 2], P [4,2], as destination external ports corresponding to the network domain (second network domain) with VLAN identifier (VID) = 2. Only one of P [4, 3] is held. In this example, the port table 15d holds only the external port (third external port) P [4, 2].

  Although not shown in FIG. 1, the line card LC [1] actually has the port table processing unit 14a and the port table 15a as in the case of the line cards LC [2] to LC [4]. Prepare. Similarly to the line card LC [1], the line cards LC [2] to LC [4] also include LC table processing units 12b to 12d and LC tables 13b to 13d, respectively. Hereinafter, each of the LC table processing units 12a to 12d will be referred to as an LC table processing unit 12, and each of the LC tables 13a to 13d will be referred to as an LC table 13 as a representative. Each of the port table processing units 14a to 14d is referred to as a port table processing unit 14, and each of the port tables 15a to 15d is referred to as a port table 15.

<< Schematic operation of relay device (this embodiment) >>
Next, an operation example of the relay apparatus in FIG. 1 will be described. As shown in FIG. 1, the line card (ingress side line card) LC [1] receives the frame at the external port P [1, 1], and adds VLAN identifier (VID) = 1 to the frame FL1. . The line card LC [1] searches for the destination of the frame FL1. Here, for example, when the destination is unknown, or when the destination is a multicast (MC) address or a broadcast (BC) address, the line card LC [1] sets the frame FL1 to VLAN identifier (VID) = 1. Relay to the network domain (first network domain) by MC or BC.

  At this time, the LC table processing unit 12a of the line card LC [1] relays the frame FL1 to the line cards LC [2] and LC [3] based on the LC table 13a. That is, the line card LC [1] uses the frame FL1 as either the line card (first line card) LC [3] or the line card (second line card) LC [4] corresponding to LAG [1]. Relay to only one of them. The port table processing unit 14b of the line card LC [2] transmits the relayed frame FL1 from the external port P [2, 1] based on the port table 15b. Similarly, the port table processing unit 14c of the line card LC [3] transmits the relayed frame FL1 from the external port P [3, 1] based on the port table 15c.

  FIG. 2 is a schematic diagram showing an operation example different from FIG. 1 in the relay apparatus of FIG. As shown in FIG. 2, the line card (ingress side line card) LC [1] receives the frame at the external port P [1,2], and adds VLAN identifier (VID) = 2 to the frame FL2. . As in the case of FIG. 1, when the destination is unknown or the destination is an MC address or a BC address, the line card LC [1] transmits the frame FL2 to the network domain (VLAN ID (VID) = 2) Relay to MC or BC to the second network domain).

  At this time, the LC table processing unit 12a of the line card LC [1] relays the frame FL2 to the line cards LC [2] and LC [4] based on the LC table 13a. The port table processing unit 14b of the line card LC [2] transmits the relayed frame FL2 from the external port P [2, 2] based on the port table 15b. Similarly, the port table processing unit 14c of the line card LC [4] transmits the relayed frame FL2 from the external port P [4, 2] based on the port table 15c. That is, the line card (third line card) LC [4] transmits the relayed frame FL2 to the external ports (third and fourth external ports) P [4, 2], P corresponding to LAG [2]. Transmit from only one of [4, 3].

<< Schematic Configuration and Operation of Relay Device (Comparative Example) >>
FIG. 8 is a schematic diagram illustrating a configuration example and an operation example of a relay apparatus studied as a comparative example of FIG. The line card LC [1] in FIG. 8 includes an LC table processing unit 37a and an LC table 38a as in the case of FIG. However, the content held in the LC table 38a is different from the content held in the LC table 13a in FIG. That is, the LC table 38a holds all line cards LC [3] and LC [4] corresponding to LAG [1] as destination line cards corresponding to the network domain of VLAN identifier (VID) = 1. Further, the line card LC [1] of FIG. 8 further includes a distributed ID calculation unit 35a and a LAG table 36a, as compared with the configuration example of FIG.

  The line card LC [3] in FIG. 8 includes a port table processing unit 39c and a port table 40c, as in the case of FIG. Further, the line card LC [3] further includes a LAG table 36c and a distributed execution unit 41c, as compared with the configuration example of FIG.

  The line card LC [4] in FIG. 8 includes a port table processing unit 39d and a port table 40d as in the case of FIG. However, the content held in the port table 40d is different from the content held in the port table 15d in FIG. That is, the port table 40d includes all external ports P [4,2], P [4,3] corresponding to LAG [2] as destination external ports corresponding to the network domain with VLAN identifier (VID) = 2. Hold. In addition, the line card LC [4] further includes a LAG table 36d and a distribution execution unit 41d as compared with the configuration example of FIG.

  The LAG tables 36a, 36c, and 36d of the line cards LC [1], LC [3], and LC [4] all hold information on each LAG set in the relay device. Specifically, as shown in the LAG table 36d, a LAG identifier (LAGID), a VLAN identifier (VID), an ID of an external port that is a member of the LAG, and a distributed ID for each external port Hold. For example, LAG [1] belonging to the network domain with VLAN identifier (VID) = 1 is composed of external ports P [3, 1], P [4, 1], and external ports P [3, 1], P [ 4, 1] are associated with the distribution IDs = 1 and 2, respectively. For example, {LAG [1]} means the identifier (ID) of LAG [1], and in the present specification, {AA} means the ID of AA.

  In such a configuration, as in the case of FIG. 1, it is assumed that the line card LC [1] relays an MC or BC frame toward the network domain with VLAN identifier (VID) = 1. The distributed ID calculation unit 35a of the line card LC [1] recognizes the presence of LAG based on the LAG table 36a, and for the frame FL1 received at the external port P [1, 1], information in the frame. Is used to calculate the distribution ID. Here, it is assumed that the distribution ID = 1 is calculated. The LC table processing unit 37a sends the frame FL1 to which the distribution ID (= 1) is added by the distribution ID calculation unit 35a to the destination line card (here, the line card LC [2], LC) determined based on the LC table 38a. [3], LC [4]).

  The port table processing unit 39c of the line card LC [3] transfers the relayed frame FL1 to the destination external port (here, P [3, 1]) based on the port table 40c via the distribution execution unit 41c. Send to. Based on the LAG table 36c, the distribution execution unit 41c determines whether or not LAG is set for the destination external port, and if set, determines whether or not the frame can be transmitted from the destination external port with the setting. The determination is made based on the distributed ID. Specifically, the distribution execution unit 41c acquires a distribution ID (here, “1”) corresponding to the destination external port (P [3, 1]) based on the LAG table 36c. The distribution execution unit 41c matches the acquired distribution ID (= 1) with the distribution ID (= 1) added to the frame FL1, and therefore from the destination external port (P [3, 1]). Allow frame transmission.

  Similarly, the port table processing unit 39d of the line card LC [4] sends the relayed frame FL1 to the destination external port (here, P [4, 1) based on the port table 40d via the distribution execution unit 41d. ]). The distribution execution unit 41d acquires a distribution ID (here, “2”) corresponding to the destination external port (P [4, 1]) based on the LAG table 36d. The distribution execution unit 41d does not match the acquired distribution ID (= 2) and the distribution ID (= 1) added to the frame FL1, so the external port (P [4, 1]) of the destination Frame transmission from is prohibited. Also, the line card LC [2] actually transmits a frame from an external port via a distributed execution unit (not shown). However, since there is no LAG setting in the line card LC [2], the case of FIG. Similarly, the frame is transmitted from the external port P [2, 1].

<< Effects of relay device (this embodiment) >>
For example, in the relay device of FIG. 8 as a comparative example, the line card LC [1] relays the frame to both the line cards LC [3] and LC [4] corresponding to LAG [1]. For this reason, an increase in communication load on the backplane 10 and an increase in processing load due to frame copying in the LC table processing unit 37a occur. Furthermore, an increase in processing load accompanying the processing of the distributed ID calculation unit 35a and the distributed execution units 41c and 41d also occurs.

  On the other hand, in the relay apparatus according to the first embodiment, as shown in FIG. 1, the line card LC [1] is only one of the line cards LC [3] and LC [4] corresponding to LAG [1]. Frames are being relayed. For this reason, it is possible to reduce the communication load on the backplane 10 and the processing load accompanying the copy of the frame in the LC table processing unit 12a. In addition, in the relay apparatus according to the first embodiment, LAG distribution is not performed only for multicast (MC) or broadcast (BC) frames, thereby reducing the processing load associated with LAG distribution processing.

  In the example of FIG. 1, the external port of LAG [1] used at the time of MC or BC is determined as the external port P [3, 1] of the line card LC [3]. Even when the port P [4,1] is set, the same effect can be obtained. That is, when the LAG is set across the line cards LC and, for example, in the following cases, the ingress side line card LC is only one of the line cards LC corresponding to the LAG at the time of MC or BC. Frames can be relayed.

  First, at least one line card (for example, LC [3]) among the line cards LC corresponding to LAG includes only one external port (P [3, 1]) in which LAG is set. Is the case. In this case, the one external port (P [3, 1]) may be used during MC or BC. Second, at least one line card (for example, LC [4]) in the line card LC corresponding to LAG is added to one external port (P [4, 1]) in which LAG is set. This is a case where other external ports (P [4,2], P [4,3]) are provided. Even in this case, the other external ports (P [4,2], P [4,3]) are different from one external port (P [4,1]) in which LAG is set. If it belongs to the network domain, the one external port (P [4, 1]) may be used for MC or BC.

  Here, when the above-described method of Patent Document 2 is used, for example, after the line card LC [1] in FIG. 1 relays the frame to the line cards LC [2] and LC [3], the line card LC [2] ] Or LC3 [3] sends out the frame from an external port in which LAG is set based on its own flooding setting table. In this case, as in the case of FIG. 8, an increase in communication load on the backplane 10 and an increase in processing load due to frame copying occur. Further, in Patent Document 1 described above, LAG setting is not particularly performed. However, if LAG setting is performed, a method similar to that in Patent Document 2 or FIG. 8 is usually used.

《Line card configuration》
FIG. 3 is a block diagram showing a configuration example of the line card in the relay apparatus of FIG. 4A is a diagram showing a configuration example of the address table in FIG. 3, FIG. 4B is a diagram showing a configuration example of the LAG table in FIG. 3, and FIG. 3 is a diagram illustrating a configuration example of a port table in FIG. The line card LC [n] shown in FIG. 3 includes (n−1) m (m is one or more) external ports P [n, 1] to P [n, m] and the backplane 10. (N-1) internal ports PI [1] to PI [n-1] connected to the respective line cards, various processing units, and various tables. Hereinafter, the various processing units and the various tables will be described.

  The interface unit 20 includes a reception buffer and a transmission buffer, and between each external port P [n, 1] to P [n, m] or each internal port PI [1] to PI [n−1]. Frames are transmitted or received. When receiving a frame at each port (external port or internal port), the interface unit 20 transmits the frame to the relay processing unit 21 after performing the following predetermined processing.

  The interface unit 20 includes a VID setting unit 25 and a VID table 26. The VID table 26 holds VLAN identifier (VID) assignment rules. Although not particularly limited, for example, when a port VLAN is used, the correspondence relationship between each external port P [n, 1] to P [n, m] and a VLAN identifier (VID) is maintained. When the VID setting unit 25 receives a frame at predetermined external ports P [n, 1] to P [n, m], the VID setting unit 25 adds a VLAN identifier (VID) determined based on the VID table 26 to the frame. . Further, when the interface unit 20 receives a frame at a predetermined external port P [n, 1] to P [n, m], the interface unit 20 includes an external port identifier (reception port identifier) of the external port that has received the frame. Is added).

  As shown in FIG. 4A, the address table FDB includes a MAC (Media Access Control) address and a VLAN identifier (VID) (in other words, a network domain), an external corresponding to the MAC address and the VLAN identifier (VID). Correspondence relationship with port identifier or LAG identifier (LAGID) is maintained. The external port identifier is an identifier that identifies the line card LC and an external port in the line card.

  In the example of FIG. 4A, for example, the MAC address MA2 belonging to the network domain with VLAN identifier (VID) = 2 exists ahead of the external port P [1,2]. The external port P [1,2] means the [2] th external port (for example, P [2]) of the [1] th line card LC [1] as can be seen from FIG. Also, for example, the MAC address MA3 belonging to the network domain with VLAN identifier (VID) = 1 exists ahead of LAG [1], and the MAC address MA5 belonging to the network domain with VLAN identifier (VID) = 1 is an external port. It exists ahead of P [2,1].

  When the relay processing unit 21 receives a frame at a predetermined port (external port or internal port), the relay processing unit 21 learns information on a transmission source included in the frame in the address table FDB. Specifically, the relay processing unit 21 transmits the source MAC address (SMAC) of the frame, the VLAN identifier (VID) added to the frame by the interface unit 20 of itself or another line card LC, and the reception port identifier. Are learned in the address table FDB. Further, the relay processing unit 21 determines the transmission source (in other words, ingress) (IN) and the destination (in other words, egress) (EG) associated with the relay of the frame, as in the following (1) to (4). Processing according to the determination result is performed.

  (1) When the transmission source (IN) is another line card and the destination (EG) is MC or BC, the relay processing unit 21 transmits the frame to the port table processing unit 14. For example, the line card of the transmission source (IN) can be identified by the reception port identifier. Whether or not the destination (EG) is MC or BC is added to the frame, for example, whether or not the destination MAC address (DMAC) is the MAC address of MC or BC, or when the destination is not learned. This can be determined by the presence or absence of a flooding flag.

  (2) When the transmission source (IN) is its own line card (for example, the reception port identifier is its own line card) and the destination (EG) is MC or BC, the relay processing unit 21 stores the frame in the LC table. It transmits to the processing unit 12.

  (3) When the transmission source (IN) is its own line card and the destination (EG) is not the MAC address of the MC or BC, the relay processing unit 21 performs destination search. In other words, when the relay processing unit 21 receives a frame at its external port P [n, 1] to P [n, m], except when the destination (EG) is the MAC address of the MC or BC. Then, the destination is searched based on the address table FDB. Specifically, the relay processing unit 21 uses the destination MAC address (DMAC) and the VLAN identifier (VID) included in the frame as search keys, or the destination external port identifier (that is, the line card and the external port), or the destination Search for a LAG identifier (LAGID).

  Here, if the search result of the address table FDB is a hit (that is, unicast (UC)) and the external port identifier is obtained as the search result, the relay processing unit 21 determines the external port identifier. After adding (called a destination port identifier) to the frame, the frame is transmitted to the relay execution unit 24. When the search result of the address table FDB is a hit and the LAG identifier (LAGID) is obtained as the search result, the relay processing unit 21 adds the LAG identifier to the frame, and then adds the frame to the distributed processing unit. 22 to send. On the other hand, when the search result of the address table FDB is a miss hit, the relay processing unit 21 adds a flooding flag or the like to the frame and transmits the frame to the LC table processing unit 12, for example.

  (4) When the transmission source (IN) is another line card and the destination (EG) is unicast (UC), the relay processing unit 21 transmits the frame to the relay execution unit 24. That is, for example, when the reception port identifier added to the frame is another line card LC and the destination port identifier added to the frame is its own external port, the relay processing unit 21 relays the frame to the relay execution unit. 24.

  As shown in FIG. 4B, the LAG table 23 holds the relationship between the LAG identifier (LAGID) for identifying the LAG and the external port identifier representing the line card and the external port that are members of the LAG identifier. To do. In the example of FIG. 4B, LAG [1] is composed of external ports P [3, 1], P [4, 1], and LAG [2] is external ports P [4, 2], P [4, 3].

  As described above, when the destination of the frame in the relay processing unit 21 is the LAG identifier, the distributed processing unit 22 determines the destination port identifier (that is, the destination line card and the external) based on the LAG table 23 and a predetermined distribution rule. Port). Specifically, the distributed processing unit 22 refers to the LAG identifier added to the frame by the relay processing unit 21 and recognizes the external port that is a member of the LAG identifier based on the LAG table 23.

  The distribution processing unit 22 performs a hash operation using the source MAC address (SMAC) and the destination MAC address (DMAC) included in the frame, but is not limited to the distribution ID obtained by the hash operation. Based on this, one external port is selected from the recognized external ports. The distribution processing unit 22 adds the external port identifier (destination port identifier) of the selected external port to the frame, and then transmits the frame to the relay execution unit 24.

  As illustrated in FIG. 1 and the like, the LC table processing unit 12 determines a destination line card LC (other line cards other than itself) based on the LC table 13. Then, the LC table processing unit 12 copies frames as many as the number of destination line cards, and adds an identifier (referred to as a destination card identifier) indicating the destination line card for each copied frame, Each frame is transmitted to the relay execution unit 24. In addition, based on the LC table 13, the LC table processing unit 12 transmits a frame to the port table processing unit 14 when the destination line card includes its own line card.

  The port table processing unit 14 determines a destination external port in its own line card based on the port table 15 as shown in FIG. Then, the port table processing unit 14 copies frames as many as the number of destination external ports and adds an identifier (destination port identifier) indicating the destination external port for each copied frame, The frame is transmitted to the relay execution unit 24. At this time, if there is a destination external port that matches the reception port identifier added to the frame, the port table processing unit 14 sets the destination external port from the destination in order to prevent the frame from being folded back. exclude.

  As shown in FIG. 4C, the port table 15 holds a relationship between a VLAN identifier (VID) (that is, a network domain) and an external port of its own destination corresponding to the network domain. In the example of FIG. 4C, the external port P [1,1] is included in the destination external port corresponding to the network domain with VLAN identifier (VID) = 1, and the network domain with VLAN identifier (VID) = 2. The external port P [1,2] is included in the corresponding external port of the destination. Although not particularly limited, the port table 15 is configured by, for example, a bitmap or the like in which “O” and “X” in FIG. 4C are associated with “1” and “0”, respectively. Similarly, the LC table 13 is also composed of, for example, a bitmap.

  The relay execution unit 24 transmits the frame from each processing unit described above toward a predetermined transmission buffer in the interface unit 20. The predetermined transmission buffer is a buffer corresponding to the destination port identifier or destination card identifier added to the frame. The transmission buffer in the interface unit 20 receives the frame from the relay execution unit 24, and corresponds to the external ports P [n, 1] to P [n, m] (that is, the external port corresponding to the destination port identifier), or The frame is transmitted to the corresponding internal ports PI [1] to PI [n−1] (that is, the internal port corresponding to the destination card identifier).

<Operation of line card>
FIG. 5 is an explanatory diagram illustrating a schematic operation example when a frame is relayed by unicast in the relay device including the line card of FIG. Here, it is assumed that the frame FL3 received at the external port P [1,1] of the line card LC [1] is relayed to the external port P [4,1] of the line card LC [4]. LAG [1] is set between the external port P [4,1] and the external port P [3,1]. The frame FL3 includes a source MAC address (SMAC) MA1 and a destination MAC address (DMAC) MA3.

  First, in the line card LC [1], the interface unit 20 receives the VLAN identifier (VID) (here, “1”) and the reception port identifier {P for the frame FL3 received at the external port P [1, 1]. [1,1]} is added and transmitted to the relay processing unit 21. The relay processing unit 21 includes a transmission source MAC address (SMAC) MA1 included in the frame, a VLAN identifier (VID) (= 1) and a reception port identifier {P [1, 1]} added by the interface unit 20 Are learned in the address table FDB (FIG. 4A).

  Further, the relay processing unit 21 has a destination MAC address (DMAC) MA3 because the transmission source (IN) associated with the relay of the frame is its own line card LC and the destination (EG) is not the MAC address of the MC or BC. The address table FDB (FIG. 4A) is searched using the VLAN identifier (VID) (= 1) as a search key. As a result, since the search result is hit and the LAG identifier {LAG [1]} is obtained as the search result, the relay processing unit 21 transmits the frame with the LAG identifier {LAG [1]} to the distributed processing unit 22. To do.

  The distributed processing unit 22 searches the LAG table 23 (FIG. 4B) based on the LAG identifier {LAG [1]}, and external ports P [3, 1], P [4] that are members of the LAG [1]. , 1]. The distributed processing unit 22 performs a hash operation using, for example, the source MAC address (SMAC) MA1 and the destination MAC address (DMAC) MA3, and based on the result of the hash operation, any one of LAG [1] An external port (here, external port P [4, 1]) is selected. The distributed processing unit 22 transmits the frame with the external port identifier (destination port identifier) {P [4, 1]} added to the relay execution unit 24. Since the destination port identifier represents the line card LC [4], the relay execution unit 24 transmits the frame to the internal port PI [3] via the interface unit 20.

  The line card LC [4] receives the frame relayed from the line card LC [1] at the internal port PI [1] and transmits the frame to the relay processing unit 21 via the interface unit 20. The relay processing unit 21 transmits the source MAC address (SMAC) MA1 included in the frame, the VLAN identifier (VID) (= 1) added by the line card LC [1], and the reception port identifier {P [1, 1 ]} Is learned from the address table FDB.

  In the relay processing unit 21, the transmission source (IN) associated with the relay of the frame is another line card (that is, the reception port identifier is {P [1,1]}), and the destination (EG) is its own external port ( That is, since the destination port identifier is {P [4,1]}), the frame is transmitted to the relay execution unit 24. The relay execution unit 24 transmits the frame to the external port P [4, 1] via the interface unit 20 based on the destination port identifier. At this time, the interface unit 20 removes various identifiers added to the frame.

  In this way, the ingress line card (LC [1]) unicasts a frame received at a predetermined external port to the LAG member ports set across the line cards LC [3] and LC [4]. When relaying, based on the distributed processing unit 22, the frame is relayed to only one of the line cards LC [3] and LC [4]. As a result, even during unicast, for example, the communication load on the backplane 10 can be reduced and the processing load associated with frame copying can be reduced compared to a configuration in which the LAG is distributed on the egress line card. It becomes possible. Although illustration is omitted, for example, when the line card LC [4] in FIG. 5 includes the LAG [2] as shown in FIG. 1, the LAG is distributed by the ingress side line card. Done.

  FIG. 6 is an explanatory diagram illustrating a schematic operation example when a frame is relayed by multicast or broadcast in the relay apparatus including the line card of FIG. Here, unlike the case of FIG. 5, it is assumed that the Leica card LC [1] has not learned the destination MAC address (DMAC) MA3 included in the frame FL3 received by the external port P [1, 1]. .

  First, in the line card LC [1], the interface unit 20 receives the VLAN identifier (VID) (here, “1”) and the reception port identifier {P for the frame FL3 received at the external port P [1, 1]. [1,1]} is added and transmitted to the relay processing unit 21. The relay processing unit 21 includes a transmission source MAC address (SMAC) MA1 included in the frame, a VLAN identifier (VID) (= 1) and a reception port identifier {P [1, 1]} added by the interface unit 20 Are learned in the address table FDB.

  In addition, since the transmission source (IN) associated with the relay of the frame is its own line card and the destination (EG) is not the MAC address of the MC or BC, the relay processing unit 21 has the destination MAC address (DMAC) MA3 and The address table FDB is searched using the VLAN identifier (VID) (= 1) as a search key. Here, when the search result is a miss hit, the relay processing unit 21 transmits, for example, a frame with a flooding flag added thereto to the LC table processing unit 12.

  In the LC table 13, the line card LC [3] is set in advance as the destination line card corresponding to the network domain of VLAN identifier (VID) = 1, as in the case of the line card LC [1] in FIG. Has been. Based on the LC table 13, the LC table processing unit 12 transmits the frame with the destination card identifier {LC [3]} added to the relay execution unit 24. Since the destination card identifier is the line card LC [3], the relay execution unit 24 transmits the frame to the internal port PI [2] via the interface unit 20.

  The line card LC [3] receives the frame relayed from the line card LC [1] at the internal port PI [1] and transmits the frame to the relay processing unit 21 via the interface unit 20. The relay processing unit 21 transmits the source MAC address (SMAC) MA1 included in the frame, the VLAN identifier (VID) (= 1) added by the line card LC [1], and the reception port identifier {P [1, 1 ]} Is learned from the address table FDB.

  In the relay processing unit 21, the transmission source (IN) associated with the relay of the frame is another line card (that is, the reception port identifier is {P [1,1]}), and the destination (EG) is MC or BC. Therefore, the frame is transmitted to the port table processing unit 14. As in the case of the line card LC [3] in FIG. 1, an external port P [3, 1] is previously stored in the port table 15 as a destination external port corresponding to the network domain with VLAN identifier (VID) = 1. Is set.

  Based on the port table 15, the port table processing unit 14 transmits a frame to which the destination port identifier {P [3, 1]} is added to the relay execution unit 24. The relay execution unit 24 transmits the frame to the external port P [3, 1] via the interface unit 20 based on the destination port identifier {P [3, 1]}. At this time, the interface unit 20 removes various identifiers added to the frame.

  As described above, by using the relay device according to the first embodiment, typically, in a chassis type relay device, it is possible to reduce the communication load inside the device.

(Embodiment 2)
<< Schematic configuration of relay device (application example) >>
FIG. 7A is a schematic diagram showing a configuration example of the relay device according to Embodiment 2 of the present invention, and FIG. 7B is a diagram of a relay system to which the relay device of FIG. 7A is applied. It is the schematic which shows the example of a structure. The relay device 30 shown in FIG. 7A includes a plurality (six in this case) of line cards LC [1] to LC [6], and each line card LC [1] to LC [6] The configuration as described in the first embodiment is provided.

  The line cards LC [1], LC [2], LC [3], LC [4] are respectively connected to the external ports P [1,1], P [2,1], P [3,1], P [ 4, 1]. The line card LC [5] includes external ports P [5,1] to P [5, m], and the line card LC [6] includes external ports P [6,1] to P [6, m]. Prepare. LAG [2] is set for the external ports P [1,1] and P [2,1], and LAG [1] is set for the external ports P [3,1] and P [4,1]. .

  The relay system of FIG. 7B has a configuration in which a plurality of relay devices 30a to 30d are connected by a dual ring network 31. Each of the relay devices 30a to 30d has a configuration as shown in FIG. The external ports P [3, 1], P [4, 1] of LAG [1] and the external ports P [1, 1], P [2, 1] of LAG [2] included in each relay device 30a-30d are Are ports for higher links connected to the ring network 31, and external ports P [5,1] to P [5, m], P [6,1] to P [6, m] are connected by terminals or the like. This is a lower link port.

  The relay device 30a is, for example, a master device of the ring network 31. When there is no failure in the ring network 31, the relay device 30a sets both the external ports P [1,1] and P [2,1] of LAG [2] to the block state. On the other hand, when a failure occurs in the ring network 31, the relay device 30a sets both the external ports P [1,1] and P [2,1] of the LAG [2] to the forward state.

  Since the frames from the lower link ports of the relay apparatuses 30a to 30d are aggregated in the ring network 31, a wide communication band is required. Therefore, as shown in FIG. 7B, it is beneficial to apply LAG to the ring network 31 to distribute the communication load.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. . Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  For example, here, the case where LAG is set across two line cards is taken as an example, but of course, the same applies to the case where LAG is set across three or more line cards. Can do. In this case, a more remarkable effect can be obtained than in the case of two line cards.

DESCRIPTION OF SYMBOLS 10 Backplane 11 Communication line 12, 12a-12d, 37a LC table process part 13, 13a-13d, 38a LC table 14, 14a-14d, 39b-39d Port table process part 15, 15a-15d, 40b-40d Port table 16 communication line 20 interface unit 21 relay processing unit 22 distributed processing unit 23, 36a, 36c, 36d LAG table 24 relay execution unit 25 VID setting unit 26 VID table 30, 30a-30d relay device 31 ring network 35a distributed ID calculation unit 41c , 41d Distributed execution unit FDB address table FL1, FL2 Frame LAG [1], LAG [2] Link aggregation group LC, LC [1] to LC [6], LC [n] Line card P [1, 1],. , [N, m] external port PI [1] ~PI [n-1] Internal Port VID VLAN Identifier

Claims (5)

A relay device comprising a plurality of line cards each having one or more external ports,
The plurality of line cards include an ingress side line card that relays a frame received at a predetermined external port to another line card, and an egress side line that transmits a frame relayed from the ingress side line card from a predetermined external port. Card, and
The first line card that is one of the egress side line cards includes a first external port, and the second line card that is any other of the egress side line cards includes a second external port,
A link aggregation group is set for the first external port and the second external port,
When the ingress side line card relays a frame received at a predetermined external port to the first network domain to which the first external port and the second external port belong by multicast or broadcast, Relay to only one of the line card and the second line card,
Relay device. The relay device according to claim 1,
Each of the plurality of line cards is
A card table that holds a relationship between a network domain and a destination line card corresponding to the network domain;
A port table that holds the relationship between the network domain and the external port of its destination corresponding to the network domain;
With
When the card table of the ingress side line card holds the first line card as the destination line card corresponding to the first network domain, the port table of the first line card contains the first network domain. The first external port is held as an external port of the destination corresponding to, and the port table of the second line card holds the second external port as the external port of the destination corresponding to the first network domain do not do,
Relay device. The relay device according to claim 2,
The third line card, which is one of the egress side line cards, includes a third external port and a fourth external port in which a link aggregation group is set,
When the frame received by the ingress side line card at a predetermined external port is relayed by multicast or broadcast to the second network domain to which the third external port and the fourth external port belong, the card table of the ingress side line card Holds the third line card as the destination line card corresponding to the second network domain, and the port table of the third line card indicates the external port of the destination corresponding to the second network domain. Holding only one of the third external port and the fourth external port;
Relay device. The relay device according to claim 2,
Each of the plurality of line cards further includes:
A LAG table that holds a relationship between a LAG identifier that identifies a link aggregation group, and a line card and an external port that are members of the LAG identifier;
An address table holding a correspondence relationship between a MAC address and a network domain, and a line card and an external port corresponding to the MAC address and the network domain, or the LAG identifier;
A relay processing unit that, when receiving a frame at a predetermined external port, searches for a destination line card and an external port or the destination LAG identifier based on the address table;
When the destination of the frame in the relay processing unit is the LAG identifier, a distributed processing unit that determines a destination line card and an external port based on the LAG table and a predetermined distribution rule;
With
When the ingress side line card relays a frame received at a predetermined external port to the first external port and the second external port for which link aggregation is set by unicast, based on the distributed processing unit, Relay the frame to only one of the first line card and the second line card;
Relay device. The relay device according to claim 2,
The first line card includes only the first external port, or additionally includes another external port, and the other external port belongs to a network domain different from the first network domain. .

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