CN100401716C - A multi-multicast protocol communication method realized on the interface of network routing equipment - Google Patents

Abstract

The invention discloses a multicast protocol communication method realized on the interface of network routing equipment, comprising: 1) configuring multiple multicast protocols on the interface of network routing equipment; 2) configuring each multicast protocol in the multiple multicast protocols and 3) when the multicast protocol on the interface is started, use the multicast protocol with the highest priority value to guide the forwarding of multicast data. The present invention introduces the concept of priority in unicast routing into the multicast protocol. When each multicast protocol is configured, it has a priority attribute. When multiple protocols coexist, the protocol with the highest priority takes effect. If the highest priority protocol is stopped or there is a routing problem, the next highest priority routing protocol will automatically come into play. In this way, multiple multicast protocols can coexist on the same interface, so that smooth switching can be directly performed among multiple multicast protocols, and the time for establishing multicast routes can be reduced.

Description

A multi-multicast protocol communication method realized on the interface of network routing equipment

technical field

The invention generally relates to network communication technology, in particular to a multi-multicast protocol communication method realized on the interface of network routing equipment.

Background technique

Traditional Internet applications use point-to-point IP transmission (unicast technology), while point-to-multipoint IP transmission (broadcast technology) is limited to the internal application of the LAN, while multicast technology is to realize point-to-multipoint IP in the wide area network. transmission technology.

In the 1980s, Steve Deering, a doctoral student at Stanford University, started research on three-layer multicast technology and published his doctoral thesis in December 1991 - "Multicast in a Datagram Network". It describes the basis of the multicast group management IGMP protocol and the multicast routing DVMRP protocol (distance vector multicast routing protocol), and successfully advances the multicast technology to the IP layer. The exploration of IP multicast technology has been going on. Based on Dr. Deering, people have successively completed multicast routing protocols such as PIM, pushing the multicast protocol to the entire Internet. The basic idea of multicast routing technology is to copy multicast data at the place closest to the receiver, so it can greatly save a lot of network bandwidth during repeated data transmission, so more and more people believe that in the future broadband Internet applications , Multicast technology will become one of the main routing protocols for multimedia data communication.

Different from unicast routing protocols, multicast routing protocols not only emphasize where the multicast data goes, but also where the multicast data comes from. In the corresponding multicast routing table entries (S, G), there are not only multicast The outbound interface of data also has the inbound interface of multicast data, because each multicast protocol generates multicast routes in different ways, so only one multicast routing protocol can take effect on each interface, so the multicast routing protocol is Interface related. In the industry's implementation, generally only one multicast protocol can be configured on an interface, and the multicast route related to the interface is generated by the routing protocol.

The unicast routing protocol has no such restrictions. For different routes of the same destination, the unicast routing protocol relies on the priority of the route to complete the route selection. The route with higher priority guides the forwarding of data, while the multicast routing protocol There is no concept of priority, so two different multicast protocols cannot be configured on the same interface.

Existing technologies generally do not support the configuration of multiple multicast protocols on the same interface, so there is no problem of using multiple protocols on the interface, but some manufacturers have realized the self-adaptive function of multiple protocols on the same interface, that is to say Configure multi-protocol adaptive mode on the interface, and then determine which protocol to use according to the protocol used by the peer neighbor when connecting with the peer neighbor.

However, the above-mentioned existing technology cannot automatically adapt to all protocols, and needs to make a dedicated interface for each protocol, so it is difficult to implement. When many multicast protocols are used, the relationship between interfaces is complicated to maintain. In addition, in the prior art, multiple protocols cannot generate their own protocol multicast routing tables, and after protocol switching, the newly functioning protocol needs to be recreated, which increases the overhead of the system.

Contents of the invention

Therefore, the present invention is made aiming at the above-mentioned problems existing in the prior art, and its purpose is to solve the problem of coexistence of multiple multicast protocols under the router interface.

In order to achieve the above object, the present invention proposes a multicast protocol communication method implemented on the interface of the network routing device, said method comprising: 1) configuring multiple multicast protocols on the interface of the network routing device; Each protocol in the plurality of multicast protocols sets a priority value respectively; and 3) when the multicast protocol on the interface is started, utilize the multicast protocol with the highest priority value to guide the flow of multicast data Forward.

The step 3) further includes the following steps: 3-1) Create a routing table item by the protocol with the highest priority value and send it to the multicast forwarding table, and use the multicast forwarding table to guide the routing of multicast data Forward.

The step 3-1) further includes the following steps: 3-1-1) the protocol with the second highest priority value only creates the routing table entry without sending it to the multicast routing table; 3-1-2) when When the protocol with the highest priority value is cancelled, the protocol with the second highest priority value uses the created multicast routing table entry to update the multicast forwarding table, and according to the updated multicast forwarding table Publish to guide the forwarding of multicast data.

The multiple multicast protocols include at least: PIM-SM protocol, PIM-DM protocol, DVMRP protocol and MOSPF protocol.

The multiple multicast protocols are arranged in order of priority values from high to low: PIM-SM protocol, PIM-DM protocol, DVMRP protocol and MOSPF protocol.

The high and low order of the priority values of the multiple multicast protocols can also be specifically configured according to specific needs.

The present invention introduces the concept of priority in unicast routing into the multicast protocol. When each multicast protocol is configured, it has a priority attribute. When multiple protocols coexist, the protocol with the highest priority takes effect. If the highest priority protocol is stopped or there is a routing problem, the next highest priority routing protocol will automatically come into play. In this way, multiple multicast protocols can coexist on the same interface, so that smooth switching can be directly performed among multiple multicast protocols, and the time for establishing multicast routes can be reduced.

Description of drawings

The above objects, features and advantages of the present invention will become more clear through the following description of the embodiments of the present invention in conjunction with the accompanying drawings. In the accompanying drawings below:

Fig. 1 is a schematic block diagram of the flow of a multi-multicast protocol communication method according to an embodiment of the present invention;

Fig. 2 is a schematic diagram of processing when a protocol change occurs in the multi-multicast protocol communication method according to an embodiment of the present invention.

Detailed ways

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

Fig. 1 is a schematic block diagram of the flow of a multi-multicast protocol communication method according to an embodiment of the present invention. As shown in Figure 1, firstly in step 1), enable the multicast function on the router. That is, configure PIM-SM and PIM-DM protocols on the same interface of the router. Then, in step 2), while configuring the multicast protocols PIM-SM and PIM-DM on the interface of the router, the priority of the PIM-SM protocol is set to 1, and the priority of the PIM-DM protocol is set to 10 . Here, referring to the definition of the priority of the unicast routing protocol, the routing protocol with a higher priority has a lower priority value. It should be noted that in the above two steps, the method of configuring the multicast protocol is different depending on the implementation of the router. For details, refer to the command manual of the router, but the configuration item of the priority of the multicast protocol is not available in the current router. In an example of the present invention, the preference command is used directly behind the protocol to specify, for example: pim-sm preference 1.

In addition, in order to record the priority of the protocol, the recording information of the priority of the multicast protocol can be added to the data structure of the interface as follows:

routing interface

{

....

  Multicast Protocol 1

Multicast Protocol 2

Multicast protocol n

....

}

The data structure of the multicast protocol is

multicast protocol

{

protocol name

Protocol priority

....

}

Each time a new multicast protocol is added to the interface, a protocol record entry is added to the data structure of the interface. Therefore, the priority information of the protocol can be obtained from the data of the interface, and the priority comparison of various protocols can be completed.

Next, in step 3), the PIM-SM and PIM-DM protocols create respective protocol multicast routing tables according to the protocol regulations, and establish a multicast network topology. The establishment of the multicast protocol complies with the provisions of the protocol, which can be realized by all routes. Since this step is well known in the art, it will not be repeated here. In step 4), since two multicast protocols work on the same interface at the same time, if the data forwarding interfaces of the two multicast protocols are inconsistent, it will cause uncertain multicast data forwarding, so there can only be one protocol to guide the data Forwarding, which is referred to in the present invention, the PIM-SM protocol with high priority generates a forwarding table according to the protocol routing table to guide data forwarding. The PIM-DM protocol does not actually participate in data forwarding.

In addition, when the protocol priority changes, the router completes the following actions:

Start the multicast protocol in the normal way, and create the routing table of the protocol.

Check whether other multicast routing protocols are configured on this interface of the router, if not, go to step 4, if yes, go to step 3

Determine the priority of the newly configured multicast protocol and the size of the existing multicast protocol. If it is less than the existing minimum priority, go to step 4, otherwise end

Refresh the multicast routing table to the multicast data forwarding table, and generate a multicast forwarding table. When the multicast data arrives at the router, look up the multicast forwarding table and forward the multicast data.

Fig. 2 is a schematic diagram of processing when a protocol change occurs in the multi-multicast protocol communication method according to an embodiment of the present invention. In Figure 2, the PIM-SM and PIM-DM protocols are taken as an example, assuming that the PIM-DM and PIM-SM protocols are respectively configured on two routers. In this way, according to the above-mentioned default priority rules, the forwarding of multicast data is controlled by the routing table created by the PIM-SM protocol, and the PIM-DM protocol only generates its own multicast protocol routing table In this way, the multicast forwarding table corresponds to the protocol routing table entry of PIM-SM. If the operation of the PIM-SM protocol is canceled at this time, the PIM-DM protocol becomes the multicast routing protocol with the highest priority, so the PIM-DM protocol will refresh the created multicast routing entries to the multicast forwarding table, so that The time required for creating multicast routes is reduced, and the efficiency of switching between various multicast protocols is improved.

While the invention has been described above with reference to specific embodiments, the above description is not meant to limit the invention. It should be apparent to those skilled in the art that various modifications and changes can be made thereto without departing from the spirit of the present invention. It is therefore intended that the scope of the invention be defined by the appended claims.

Claims (6)

1. A multi-multicast protocol communication method realized on a network routing device interface, said method comprising: 1) Configure multiple multicast protocols on the interface of the network routing device; 2) setting a priority value for each of the plurality of multicast protocols; and 3) When the multicast protocol on the interface is started, use the multicast protocol with the highest priority value to guide the forwarding of the multicast data. 2. method according to claim 1, is characterized in that, described step 3) further comprises the following steps: 3-1) The multicast protocol with the highest priority value creates a routing table entry and sends it to the multicast forwarding table, and uses the multicast forwarding table to guide the forwarding of multicast data. 3. method according to claim 2, is characterized in that, described step 3-1) further comprises the following steps: 3-1-1) The multicast protocol with the next highest priority value only creates routing table entries and does not send them to the multicast routing table; and 3-1-2) When the multicast protocol with the highest priority value is cancelled, the multicast protocol with the second highest priority value uses the multicast routing table entry that has been created to update the multicast forwarding table Update and guide the forwarding of multicast data according to the updated multicast forwarding table. 4. The method according to any one of claims 1 to 3, wherein the multiple multicast protocols at least include: Sparse Mode Independent Multicast Protocol, Dense Mode Independent Multicast Protocol, Distance Vector Multicast Routing Protocol and Multicast Extended Open Shortest Path First Protocol. 5. The method according to claim 4, wherein the plurality of multicast protocols are arranged according to the order of priority values from high to low: sparse mode independent multicast protocol, dense mode independent multicast protocol, Distance Vector Multicast Routing Protocol and Multicast Extension Open Shortest Path First Protocol. 6. The method according to claim 4, characterized in that the order of the priority values of the multiple multicast protocols is specifically configured according to specific needs.

Images