KR100487126B1 - Method for handling display of local routing table entries in distributed architecture router - Google Patents

Abstract

The present invention relates to a method for providing routing information in a distributed router. In particular, in a distributed router, routing information in a distributed router such that an internal interface port number is not displayed to the outside when a route entry of a routing table is externally viewed. It is about a provision method.

In addition, according to the present invention, in a distributed router including a plurality of routing processors and a switching unit, when a routing information display command is input, the switching unit interfaces with a route entry in the routing information received by receiving routing information in the routing processor. Search for a route entry that contains an internal interface port number in the field, extract the network number from the next hop address of the found route entry, search for an external interface port with the same network number as the extracted network number, and then search for the external interface port found. The routing information providing method for providing the operator with routing information including the route entry in which the interface field value is replaced with the identifier of the external interface port by replacing the identifier of the interface with the interface field value of the corresponding route entry is provided. Ball.

Description

Method for handling display of local routing table entries in distributed architecture router

The present invention relates to a method for providing routing information in a distributed router. In particular, in a distributed router, routing information in a distributed router such that an internal interface port number is not displayed to the outside when a route entry of a routing table is externally viewed. It is about a provision method.

In general, a router is composed of four components: an input port, an output port, a switching fabric, and a routing processor.

The input port is the point of contact with the physical link and the gateway to accepting packets. The switching fabric internally connects the input port to the output port.

The output port accumulates and schedules the packets to send the packets to the output link.

Finally, the routing processor handles the routing protocol and creates a forwarding table that is used for packet forwarding.

If the routing function is implemented in software running in the processing environment, bottlenecks occur when the processing power does not keep up with the input rate of the packet.

In addition, in the routing process, the packet forwarding part that retransmits the header with new header information is dependent on the flow rate of traffic.

Recently, as the Internet traffic increases exponentially, a distributed router having a distributed structure has been proposed to accommodate the increase of the Internet traffic.

In addition, in order to speed up a routing function, a high speed forwarding engine technology having separate packet forwarding parts has been developed.

Therefore, in terms of the system structure, a distributed structure in which the forwarding engine is distributed to each line connection unit is preferred to the server type structure in which the forwarding engine unit is shared.

Such a distributed router performs a routing function and a packet forwarding function on different processors in a distributed manner, and details thereof will be described with reference to the accompanying drawings.

1 is a configuration diagram illustrating a configuration of a routing entry in a conventional distributed router.

Referring to FIG. 1, a distributed router includes physical connections 11 to 1n for input / output, routing processors 21 to 2n for performing a routing function and a packet forwarding function, and routing between each routing processor 21 to 2n. And a switching unit 30 for providing information exchange and connection buses, and a backup switching unit 31 for redundancy.

When the packets come in, the routing processors 21-2n search the routing tables 21a-2na to forward the packets to the gateway corresponding to the packet's destination address.

For example, when a packet having a destination address of 200.1.1.1 enters the routing processor 1 21 through the physical connection 11, the routing processor 1 21 searches the routing table 21a. At this time, the gateway address 10.2.1.2 corresponding to the destination address 200.1.1.1 is retrieved from the routing entry of the routing table 21a. Accordingly, the packet is switched at the switching unit 30 and the packet is forwarded to the physical connection unit 12 through the routing processor 2 22.

On the other hand, in the routing table of the routing processors 21 to 2n, an internal interface port number is designated in the interface field of the route entry via the routing processors 21 to 2n existing therein.

That is, if routing processor 1 (21) has a route entry with a destination address of 200.1.1.1 and a gateway address of 10.2.1.2 (that is, in a routing path via internal routing processor 2 (22)). In the interface field, an internal interface port number is used. For example, eIPC0 is used.

In addition, if routing processor 2 22 has a route entry with a destination address of 100.1.1.1 and a gateway address of 10.1.1.2 (that is, for a routing path via internal routing processor 1 (21)). In the interface field, an internal interface port number is used. For example, eIPC0 is used.

And if there is a route entry in routing processor 3 (23) with a destination address of 200.1.1.1 and a gateway address of 10.2.1.2 (i.e. in a routing path via internal routing processor 2 (22)). In the interface field, an internal interface port number is used. For example, eIPC0 is used. As such, when eIPC0 is designated as an internal interface port number in the interface field, when the routing table information of the distributed router is displayed to the outside, the internal interface port number is displayed to the outside.

However, even in a distributed router, it is necessary to operate as a router externally, and the internal interface port number should not be visible to the outside.

Therefore, when showing the routing table of a distributed router to the outside, the route entry containing the internal interface port number needs to be modified.

Accordingly, the present invention has been made to solve the above problems, the route entry of the routing table so that the internal interface port number is not exposed when showing the routing information of the routing table internally distributed by the distributed router It is an object of the present invention to provide a routing information providing method in a distributed router in which the modified route entry is changed to show a changed route entry.

According to the present invention for achieving the above object, in a distributed router including a plurality of routing processors and switching unit, when a routing information display command is input, the switching unit requests the routing processor to transmit routing information and transmits a route entry. Determining whether an internal interface port number is included in an interface field of a route entry received and transmitted; As a result of the determination of the first step, if the interface field of the route entry includes the internal interface port number, the network number is extracted by performing a netmask on the next hop address of the route entry, and the sequential net for the IP address of the external interface port. Performing a mask to search for an external interface port having the same network number as the network number extracted from the next hop address; Designating an identifier of an external interface port retrieved in the second step as an interface field value of a corresponding route entry and requesting routing information transmission to the routing processor of the first step until all routing information is received from the routing processor. Repeating the third step from; And a fourth step of providing the operator with the routing information including the route entry in which the interface field value is replaced with the identifier of the external interface port as a result of the third step.

According to another aspect of the present invention, there is provided a distributed router including a plurality of routing processors and a switching unit, the switching unit comprising: a first step of receiving routing information in the routing processor when a routing information display command is input; A second step of searching for a route entry including an internal interface port number in an interface field of the route entry in the routing information received in the first step; A network number is extracted by performing a netmask on the next hop address of the route entry retrieved in the second step, and a network number identical to the network number extracted from the next hop address by performing a sequential netmask on the IP address of the external interface port. Searching for an external interface port having a third step; A fourth step of designating an identifier of an external interface port retrieved in the third step as an interface field value of a corresponding route entry; A fifth step of repeating from the second step until all the route entries including the internal interface port number in the interface field in the routing information received in the first step are replaced; And a sixth step of providing the operator with routing information including the route entry in which the interface field value is replaced with the identifier of the external interface port as a result of the repetition of the fifth step.

2 is a block diagram of a distributed router for providing routing information of a routing table according to an embodiment of the present invention.

Referring to FIG. 2, a distributed router for providing routing information of a routing table according to an embodiment of the present invention performs a plurality of physical connections 110-1n0 for input / output, a routing function, and a packet forwarding function. A plurality of routing processors 210 to 2n0, a switching unit 300 for providing routing information exchange and connection buses between each routing processor 210 to 2n0, and a backup switching unit 310 for redundancy. .

Each routing processor 210 to 2n0 has a routing table, and determines a partner to forward (route) a packet sent to it according to the routing information recorded in the routing table.

That is, the routing processors 210 ˜ 2n0 determine the progress direction of the data packet based on the information included in the routing table.

In addition, the routing information of the routing table has a destination network number rather than a physical address of each destination host.

The routing table is created based on the network number rather than the host address, so the amount of information needed to maintain its own routing table in the route processors 210-2n0 is directly proportional to the number of networks that make up the Internet.

For this reason, since the route processors 210 to 2n0 do not manage information on every single host directly connected to the Internet, the route table can be reduced in size.

In general, there are two ways to manage routing tables: static routing and dynamic routing.

Static routing is a way for an administrator to specify a specific location, that is, a router, to which the routing processor 210-2n0 is to connect.

Dynamic routing is accomplished by incorporating "intelligence" functionality into the routing processors 210-2n0. That is, dynamic routing is a method in which routing processors 210 to 2n0 exchange information between networks to which they are connected, and the routing table is automatically updated and created.

Most high-level protocols provide dynamic routing that automatically creates a routing table by the routing processor 210-2n0.

Dynamic routing algorithms automatically respond to network congestion or changes in network topology.

To do this, routing processors 210-2n0 use special packets with path-based information.

New changes are shared with each network to add or delete new network paths from their routing table.

Dynamic routing is now a tool of many styles, and the discussion of routing schemes focuses on dynamic routing.

In general, to help with the creation and maintenance of routing tables, routing processors 210-2n0 must detect when changes occur in the network.

Examples of such information could be the existence of a new path in the network or the fact that there is no previous path.

Due to the growing number of routing tables, the amount of routing information is enormous. This variability first depends on the protocol used by the routing algorithm.

In general, two kinds of dynamic routing algorithms are used by computer networks to maintain their routing tables and calculate the shortest route to the destination.

It is a "distance-vector" algorithm (known as "Bellman-Ford") and a "link-state" algorithm (known as "Shortest Path First" or "Dijkstra").

Every routing algorithm must use an array to select the best route to its destination. The shortest path between networks is chosen by the router with the fewest arrays, and all the routers tested and determined for their destinations.

The least costly routed array calculates hops, delays in change, line capacity, or administratively determined distances.

In the Distance-Vector Algorithm, a router sends a distance vector to its neighbors (its routing table). Thus each router knows the length of the shortest path from its neighbor routers to all other networks. The router uses this information to calculate the shortest path to each destination by selecting the neighbor with the shortest possible path.

In Link-State Algorithms, each router must know the overall network topology before calculating the shortest path of each destination network.

Each router floats the updated message to all other routers in the routing domain. This message contains an array and the connection status of each router. The path must be consistent because all routers use the same routing algorithm on the same database.

Any topology change found at the local router must be known as broadcast or multicast to all other routers in the routing domain. Each node with all the information has to calculate its own shortest path from the routing domain to the other network.

Meanwhile, in a distributed router, routing processors 210 to 2n0 process data packets received from an internal / external interface connected thereto, and each routing processor 210 to 2n0 exchanges routing information thereof. Is synchronized.

In addition, each routing processor 210 to 2n0 manages routing information received from another routing processor 210 to 2n0 via the switching unit 300 and an internal interface to set internal metric to 0 for internal communication. Prevent the increase of the metric by

Each routing processor 210-2n0 searches its own routing table to know how to forward the packet.

If the destination is directly connected to the network, the routing processor 210-2n0 can send a packet without the service of another external router. However, if the destination is in a remote network, the routing processor 210-2n0 must send a packet to another external router to find the last destination. The route to the remote network can be statically configured or dynamically learned through a routing protocol such as RIP, OSPF, or EGP.

In the distributed router, the routing processors 210 to 2n0 operate as independent routers so that if the destination is directly connected to the network, the routing processors 210 to 2n0 may be connected to other routing processors 210. A packet can be sent without the service of ~ 2n0).

However, if the destination is not directly connected to its port, the routing processors 210 to 2n0 must forward the packet through an external router or through another internal routing processor 210 to 2n0.

The routing table contains one entry (row) for each routing processor 210-2n0. The routing table consists of a destination IP address field, a next hop address field, an interface field, a metric field, and a time field.

The destination IP address field specifies the destination IP address, not the IP address of the next device to receive the packet, but the 32-bit IP address of the final destination to receive the packet.

When the packet is received, the routing processors 210 to 2n0 search the routing table for a route entry having a destination IP address that is the same as the packet's destination IP address.

If there is a route entry having the same destination IP address as a result of the search, the packet is routed according to the routing information of the found route entry.

The next hop address field is assigned a next hop address, and the routing processor 210 to 2n0 looks at the next hop address and routes the packet to the corresponding router.

Next, in the interface field, an interface IP address of the routing processor 210 to 2n0 belonging to the same network as the next hop address to the corresponding path is designated, and symbol names such as eth0 and eth1 are used.

In the routing table managed by the routing processors 210 to 2n0 of the distributed router, the interface field of the route entry having routing information via the routing processors 210 to 2n0 existing therein is represented by an internal interface port number. In this example, eIPC0 is used.

The metric field specifies a metric value, where the metric takes the time it takes to arrive at the destination network, the total number of links formed in the path from the router to the destination network, and the destination based on the bandwidth usage mechanism to arrive at the destination network. Indicates the cost of

The switching unit 300 stores an interface IP address reference table as shown in Table 1 below.

Referring to (Table 1), the routing processor number is designated in the vertical column of the interface IP address reference table, the port number is designated in the horizontal column, and the interface IP for each port of each routing processor 210 ~ 2n0. An address is provided.

For example, it can be seen that the interface of port 1 of routing processor 1 is 10.1.1.1, and that port 2 of routing processor 2 is 10.2.2.1.

Port / routing processor Port 1 Port 2 ... Port n Routing Processor 1 10.1.1.1 10.1.2.1 ... 10.1.n.1 Routing Processor 2 10.2.1.1 10.2.2.1 ... 10.2.n.1 Routing Processor 3 10.3.1.1 10.3.2.1 ... 10.3.n.1       .       .       .       .       .       .

In addition, each routing processor number in Table 1 corresponds to a slot number in which each routing processor 210 to 2n0 is mounted. That is, the slot number on which the routing processor 1 210 is mounted is # 1, and the slot number on which the routing processor 2 220 is mounted is # 2. Of course, if each routing processor number does not correspond to the slot number in which it is mounted, the switching unit 300 should have a separate reference table accordingly.

Of course, the switching unit 300 should store a shelf number (shelf #) that is information on which shelf the distributed router is mounted in a larger system.

The switching unit 300 reads the interface IP address for each port from each routing processor 210 ˜ 2n0 in the setup of the distributed router, and stores the interface IP address in the interface IP address reference table.

When the operator wants to see the routing table of the distributed router, that is, when the operator wants to see the routing information in the routing table and inputs a routing information display command, the switching unit 300 performs each routing processor 210 to the distributed router. The routing information of the routing table in 2n0) should be read and displayed on the display.

At this time, when the switching unit 300 shows the routing information of the routing table in each routing processor 210 to 2n0 of the distributed router without modification, the internal interface port number specified in the interface field is shown to the outside. .

Therefore, the switching unit 300 should modify the route entry including the internal interface port number when showing the routing table of the distributed router to the outside.

And, this modification is when the operator wants to see the routing table of the distributed router, the switching unit 300 loads the routing table of each routing processor (210 ~ 2n0) of the distributed router, the port of the interface in the interface field This can be done by modifying the number to shelf # / slot # / port # or by outputting the interface IP address.

The switching unit 300 performs a netmask on the next hop address in the route entry to find the shelf # / slot # / port # corresponding to the port number of the interface in the interface field or to find the interface IP address. To extract the network number.

In this case, the netmask indicates which part of the corresponding IP address is to be a network number part, and a bit value of a netmask corresponding to the network number. Is 1 and the bit value of the netmask corresponding to the host number is 0.

Class A IP addresses use netmask 255.0.0.0, Class B IP addresses use netmask 255.255.0.0, and Class C IP addresses use netmask 255.255.255.0 is used, and in accordance with the present invention, various netmasks may be performed according to a network situation connected to a port of a distributed router.

Then, the switching unit 300 performs a netmask for the interface IP address in the interface IP address reference table of Table 1 to find the interface IP address having the same network number.

As a result of performing the netmask for the interface IP address in the interface IP address reference table of (Table 1), if the interface IP address with the same network number exists, the routing processor number and port number of the corresponding interface IP address are detected.

In addition, since the corresponding routing processor number corresponds to the shelf number, the switching unit 300 uses the corresponding routing processor number as the slot number. Of course, if the routing processor number does not match the shelf number, a corresponding reference table may be used to find a correspondence.

Thereafter, the switching unit 300 replaces the shelf number / slot number / port number detected above with the corresponding interface port number in the route entry of the routing table, and then provides the replaced route entry to the user.

3 is a flowchart illustrating a routing information providing method in a distributed router according to an embodiment of the present invention.

Referring to FIG. 3, in the distributed router according to an embodiment of the present invention, in the routing information providing method, first, when a switching unit displays a routing information display command from an operator (for example, a command of “Route # Show ip Route”) is performed. (Step S110), the routing processor requests the transmission of the routing information of the routing table (S112).

When the switching unit receives the routing information from the routing processor (step S114), it determines whether the internal interface port number is included in the interface field in the route entry of the received routing table (step S116).

As a result, when a route entry including the internal interface port number is found, a network mask is obtained by performing a netmask on the next hop address of the corresponding route entry (step S118).

Subsequently, in order to find out the route processor number and the port number having the same interface IP address, netmask is sequentially performed on the interface IP address in the interface IP address reference table (step S120) and the network number in the next hop address. It is determined whether an interface IP address having the same network number as is found (step S122).

As a result of the determination, if no interface IP address with the same network number is found, the process is repeated from step S120 until an interface IP address with the same network number is found, and if an interface IP address with the same network number is found, the interface is found. The field value is changed to the shelf number # / slot number # / port number # corresponding to the corresponding route processor number and port number (step S124). Here, the interface port number and the port number are different from each other.

Subsequently, it is determined whether the reception of the routing information from the route processor is finished (step S126), and if the routing information reception is completed, the routing information is displayed on the display unit (step S128). Of course, if the reception of the routing information is not finished, the process is repeated from step S114.

Meanwhile, in the present invention, the interface port number is replaced with a shelf number / slot number / port number, but may be provided by replacing with an interface IP address.

 Although the preferred embodiments of the present invention have been described in detail above, those skilled in the art will appreciate that the present invention may be modified without departing from the spirit and scope of the invention as defined in the appended claims. It will be appreciated that modifications or variations may be made. Therefore, changes in the future embodiments of the present invention will not be able to escape the technology of the present invention.

According to the present invention as described above, there is an effect that the internal interface port number in the route entry of the routing table is not visible to the distributed router.

1 is a configuration diagram illustrating a form of configuring a routing entry in a conventional distributed router.

2 is a block diagram of a distributed router for providing routing information according to an embodiment of the present invention.

3 is a flowchart of a routing information providing method in a distributed router according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110 ~ 1n0: Physical connection 210 ~ 2n0: Routing processor

300: switching unit 310: backup switching unit

Claims (9)

In a distributed router including a plurality of routing processors and switching units, A first step of, when a routing information display command is input, the switching unit requests routing information transmission from the routing processor to determine whether an internal interface port number is included in an interface field of the received route entry; As a result of the determination of the first step, if the interface field of the route entry includes the internal interface port number, the network number is extracted by performing a netmask on the next hop address of the route entry, and the sequential net for the IP address of the external interface port. Performing a mask to search for an external interface port having the same network number as the network number extracted from the next hop address; Designating an identifier of an external interface port retrieved in the second step as an interface field value of a corresponding route entry and requesting routing information transmission to the routing processor of the first step until all routing information is received from the routing processor. Repeating the third step from; And And a fourth step of providing the operator with the routing information including the route entry in which the interface field value is replaced with the identifier of the external interface port as a result of the third step. The method of claim 1, The identifier of the external interface port is, Routing information providing method characterized in that the IP address of the external interface port. The method of claim 1, The identifier of the external interface port is, A routing number, slot number, and port number, characterized in that the routing information providing method. The method according to any one of claims 1 to 3, The first step is, Step 1-1 of requesting transmission of routing information of a routing table to the routing processor when a routing information display command is input from an operator; And And the switching unit comprises a step 1-2 determining whether an internal interface port number is included in an interface field in the received route entry when receiving the route entry from the routing processor. The method according to any one of claims 1 to 3, The second step, A second step of extracting a network number by performing a netmask on a next hop address of the route entry retrieved in the first step; And And performing a netmask on the external interface IP address of the distributed router sequentially to retrieve the interface IP address having the same network number as the network number in the next hop address. . The method of claim 4, wherein The second step, A second step of extracting a network number by performing a netmask on a next hop address of the route entry retrieved in the first step; And And performing a netmask on the external interface IP address of the distributed router sequentially to retrieve the interface IP address having the same network number as the network number in the next hop address. . In a distributed router including a plurality of routing processors and switching units, A first step of receiving the routing information in the routing processor when a routing information display command is input; A second step of searching for a route entry including an internal interface port number in an interface field of the route entry in the routing information received in the first step; A network number is extracted by performing a netmask on the next hop address of the route entry retrieved in the second step, and a network number identical to the network number extracted from the next hop address by performing a sequential netmask on the IP address of the external interface port. Searching for an external interface port having a third step; A fourth step of designating an identifier of an external interface port retrieved in the third step as an interface field value of a corresponding route entry; A fifth step of repeating from the second step until all the route entries including the internal interface port number in the interface field in the routing information received in the first step are replaced; And And a sixth step of providing the operator with routing information including a route entry in which the interface field value is replaced with an identifier of an external interface port as a result of the repetition of the fifth step. The method of claim 7, wherein The identifier of the external interface port is, Routing information providing method characterized in that the IP address of the external interface port. The method of claim 7, wherein The identifier of the external interface port is, A routing number, slot number, and port number, characterized in that the routing information providing method.