CN102571375A

CN102571375A - Multicast forwarding method and device as well as network device

Info

Publication number: CN102571375A
Application number: CN2012100288170A
Authority: CN
Inventors: 张明振
Original assignee: Beijing Star Net Ruijie Networks Co Ltd
Current assignee: Beijing Star Net Ruijie Networks Co Ltd
Priority date: 2012-02-09
Filing date: 2012-02-09
Publication date: 2012-07-11
Anticipated expiration: 2032-02-09
Also published as: CN102571375B

Abstract

The invention provides a multicast forwarding method and a device as well as a network device. The method comprises the following steps: a first PE (Provider Edge) in a first VPN (Virtual Private Network) receives a private network multicast message transmitted by a multicast source in the first VPN; the first PE encapsulates the private network multicast message according to a public network multicast address of MD (Multicast Domain) that the second PE belongs to in the second VPN configured under the MVRF (Multicast Virtual Routing and Forwarding) of the first PE to generate a public network multicast message whose destination address is the public network multicast address of the MD that the second PE belongs to, and transmits the public network multicast message to the second PE so that the second PE restores the public network multicast message into the private network multicast message and then transmits to the second VPN. The technical proposal of the invention ensures that the amount of MT (Multicast Tunnel) established between the VPN and the PE configured on the PE is reduced during VPN multicast spanning, and the resources of VPN and MT are saved.

Description

Multicast forward method, device and the network equipment

Technical field

The present invention relates to the network communications technology, relate in particular to a kind of multicast forward method, device and the network equipment.

Background technology

Multiprotocol label switching (Multiprotocol Label Switching, MPL S) is a kind ofly not re-use traditional routing table and carry out data forwarding, but through searching the agreement of the label decision forwarding behavior in the message.(Virtual Private Network is a kind of based on the Border Gateway Protocol (technology of the multicast packet in the Border Gateway Protocol, three layers of (L3) MPLS VPN Internet communication VPN BGP) VPN) to the multicasting virtual private network network.Wherein, (Multicast-Domain MD) is a kind of scheme that realizes multicasting VPN, i.e. MD VPN scheme to multicast domain.The corresponding MD of each VPN, this MD covered in this VPN alternately all provider's edge routers of multicast packet (Provider Edge Router, PE).In MD VPN scheme, MD is regarded as public network, and is regarded as private network outside this MD.Each MD distributes an independently multicast address on public network; Be called shared group (Share-Group) address; It is the unique sign of MD on public network, be used on public network, setting up the pairing multicast distribution tree of MD (Multicast Distribution Tree, MDT).MDT has defined the path between each PE of multicast data transmission among the MD, comprises default MDT (Default-MDT) and data M DT (Date MDT).(Multicast Tunnel MT) connects together each PE through Multicast Tunnel in MD.(Multicast Tunnel Interface is going into/exporting of MT MTI) to Multicast Tunnel Interface, is equivalent to going into/exporting of MD.PE is connected on the MT through MTI.Inner at MD, the private network data are transmitted through MT.The MT transmission course is: local PE is packaged into the public network multicast message with the private network multicast message, and in public network, carries out multicast forwarding, and far-end PE is reduced into the private network multicast message through decapsulation with it after receiving this public network multicast message.

Fig. 1 is a kind of network diagram that realizes multicasting VPN in the prior art.As shown in Figure 1, and PE1, PE2 and convergent point (Rendezvous Point, RP) 3 constitute MD, Customer Edge router (Customer Edge Router, CE) 4 are connected with PE1, and CE5 is connected with PE2.Wherein, CE4 and CE5 belong to same VPN.In this network architecture; MD is regarded as public network; After CE4 sends to PE1 with the private network multicast message among the VPN (supposing that the source address of this private network multicast message and destination address are respectively 192.168.1.1 and 224.1.1.1); PE1 is according to multicasting VPN route forwarding table (the Multicast VPN Routing and Forwarding of correspondence; MVRF) multicast message of private network being sent to MTI goes up and converts the public network multicast message into and (suppose that source address and destination address behind the public network multicast message are respectively 10.1.1.1,239.1.1.1), send among the MT then; Be transmitted to other PE (for example PE2) in this MD through MT, on PE2, convert the public network multicast packet into the private network multicast packet again.

In actual application, need the scene of the service of a shared VPN of different VPN visit through regular meeting.The multicast requirement of VPN this moment will appear striding in business as shown in Figure 2, that the subscriber equipment 21 under the VPN needs the multicast server 27 among visit the 2nd VPN to provide.Because different VPN is corresponding to different MD, and be separate between each MD.Solving the method for striding the VPN multicast in the prior art is; Configuration the 2nd VPN on the PE23 that CE22 in a VPN connects; Make PE23 through RP24 with the 2nd VPN in the PE25 that is connected of CE26 belong to the MD of corresponding the 2nd VPN; In this MD, set up MT between each PE, accomplish the transmission of private network multicast packet through MT.Perhaps, configuration the one VPN on PE25 makes PE23 and PE25 belong to the MD of a corresponding VPN, between each PE of this MD, sets up MT, accomplishes the forwarding of private network multicast packet through MT.

By above-mentioned visible,, need make two PE belong to a MD at the VPN (this VPN need not exist this side PE) under configuration the opposing party on a side the PE, and between two PE, set up corresponding M T in order to realize striding the multicast between the VPN.But it all is limited that every equipment allows the VPN of configuration and the MT number of being supported, will reduce effective VPN and MT resource like this, causes the waste of VPN and MT resource.

Summary of the invention

The present invention provides a kind of multicast forward method, device and the network equipment, in order to when realizing striding the VPN multicast, to reduce the MT quantity of setting up between the VPN that disposed on the PE and the PE, practices thrift VPN and MT resource.

The present invention provides a kind of multicast forward method, comprising:

PE in the one VPN receives the private network multicast message that the multicast source in the VPN sends, and the destination address of said private network multicast message is the private network multicast address of the 2nd VPN;

A said PE is according to the public network multicast address of MD under the 2nd PE in said the 2nd VPN that under the MVRF of a said PE, disposes in advance; Said private network multicast message is carried out encapsulation process generate the public network multicast message, the destination address of said public network multicast message is the public network multicast address of MD under said the 2nd PE;

A said PE through and said the 2nd PE between Multicast Tunnel MT said public network multicast message is sent to said the 2nd PE so that said the 2nd PE is forwarded in said the 2nd VPN after said public network multicast message is reduced to said private network multicast message.

The present invention provides a kind of multicast forwarding device, comprising:

The message receiver module is used to receive said multicast forwarding device and belongs to the private network multicast message that the multicast source in the VPN sends, and the destination address of said private network multicast message is the private network multicast address of the 2nd VPN;

Package module; Be used for public network multicast group address according to MD under the multicast forwarding device in said the 2nd VPN that under the MVRF of said multicast forwarding device, disposes in advance; Said private network multicast message is carried out encapsulation process generate the public network multicast message, the destination address of said public network multicast message is the public network multicast address of MD under the multicast forwarding device in said the 2nd VPN;

Sending module; Be used for said public network multicast message being sent to the multicast forwarding device in said the 2nd VPN, so that the multicast forwarding device in said the 2nd VPN is forwarded in said the 2nd VPN after said public network multicast message is reduced to said private network multicast message through the Multicast Tunnel MT between the multicast forwarding device in said multicast forwarding device and said the 2nd VPN.

The present invention provides a kind of network equipment, comprises arbitrary multicast forwarding device provided by the invention.

Multicast forward method provided by the invention, device and the network equipment; Public network multicast address through MD under the 2nd PE of configuration the 2nd VPN under the MVRF of the PE of a VPN; By a PE private network multicast message of the one VPN is encapsulated as the public network multicast message that destination address is the multicast address of MD under the 2nd PE; Send the 2nd PE through the Multicast Tunnel between a PE and the 2nd PE then; And then be forwarded to the 2nd VPN after by the 2nd PE the public network multicast message being reduced to the private network multicast message, realize striding the multicast of VPN, and need on a PE or the 2nd PE, not dispose unwanted VPN; Just need not set up Multicast Tunnel yet, practice thrift VPN and tunnel resource for the VPN of configuration.

Description of drawings

Fig. 1 is a kind of network diagram that realizes multicasting VPN in the prior art;

Fig. 2 is another network diagram that realizes multicasting VPN in the prior art;

The flow chart of the multicast forward method that Fig. 3 provides for one embodiment of the invention;

The flow chart of the multicast forward method that Fig. 4 provides for another embodiment of the present invention;

A kind of network diagram of the MD VPN that Fig. 5 provides for one embodiment of the invention;

The structural representation of the multicast forwarding device that Fig. 6 provides for one embodiment of the invention;

The structural representation of the multicast forwarding device that Fig. 7 provides for another embodiment of the present invention;

The structural representation of the multicast forwarding device that Fig. 8 provides for further embodiment of this invention.

Embodiment

The flow chart of the multicast forward method that Fig. 3 provides for one embodiment of the invention.As shown in Figure 3, the method for present embodiment comprises:

PE in step 301, the VPN receives the private network multicast message that the multicast source in the VPN sends, and the destination address of said private network multicast message is the private network multicast address of the 2nd VPN.

Wherein, during multicast service that the multicast source in the user in the 2nd VPN need visit a VPN provides, can send multicast request to the multicast source in the VPN.Multicast source in the one VPN can provide service according to the user of multicast request in the 2nd VPN.Concrete, the private network multicast message that the multicast source in the VPN sends can be transmitted to the PE in the VPN through the CE in the VPN.

In MD VPN scheme, a PE can dispose a plurality of VPN.PE in the one VPN of present embodiment be meant with a VPN in CE be connected, and with a VPN in the interface that is connected of CE on disposed a VPN.

The one PE receives the private network multicast message of being transmitted by the CE in the VPN.Concrete, the CE in the VPN sends to a PE through the PIM agreement with the private network multicast message.

The public network multicast address of MD under the 2nd PE in the 2nd VPN that step 302, PE basis dispose under the MVRF of a PE in advance; The private network multicast message is carried out encapsulation process generate the public network multicast message, the destination address of said public network multicast message is the public network multicast address of MD under the 2nd PE.

In the present embodiment, the PE in the VPN has disposed the public network multicast address of MD under the 2nd PE in the 2nd VPN in advance under its MVRF, and the MVRF that is about to a PE binds with the public network multicast address of the affiliated MD of the 2nd PE.Wherein, the 2nd PE in the 2nd VPN be meant with the 2nd VPN in CE be connected, and with the 2nd VPN in the interface that is connected of CE on disposed the 2nd VPN.In the present embodiment, MD is meant the MD corresponding to the 2nd VPN under the 2nd PE, and the public network multicast address of MD is meant the multicast address corresponding to the MD of the 2nd VPN under the 2nd PE.

Do not dispose the 2nd VPN on the one PE of present embodiment, and do not dispose a VPN on the 2nd PE of present embodiment, can not dispose other VPN simultaneously but do not limit on a PE and the 2nd PE.For example, can dispose the 3rd VPN simultaneously on a PE and the 2nd PE, that is to say, a PE and the 2nd PE belong to the 3rd VPN.

In the present embodiment; The public network multicast address of the one PE MD under configuration the 2nd PE under its MVRF; After receiving the private network multicast message of a VPN; Encapsulate the public network multicast address of MD under address and the 2nd PE of loopback interface of a PE through skin again, generate the public network multicast message at the private network multicast message.Wherein, the address of the loopback interface of a PE is meant that a PE is used to set up bgp protocol neighbours' IP address, just the IP address of MTI.

Because a PE is at the public network multicast address that has disposed MD under the 2nd PE under its MVRF; Therefore; The one PE can be as the private network multicast message that in a VPN, carries out multicast is handled the private network multicast message that sends to the 2nd VPN after receiving the private network multicast message.Difference is that the destination address of the public network multicast message that a PE obtains after the private network multicast message that sends to the 2nd VPN is encapsulated is the multicast address of the corresponding MD of the 2nd VPN, rather than the multicast address of the MD of VPN correspondence.

Step 303, a PE through and the 2nd PE between MT the public network multicast message is sent to the 2nd PE so that the 2nd PE is forwarded in the 2nd VPN after the public network multicast message is reduced to the private network multicast message.

After the private network multicast message in the VPN was encapsulated as the public network multicast message, a PE sent to the 2nd PE through the MT between itself and the 2nd PE with the public network multicast message.

The 2nd PE through and a PE between MT receive the public network multicast message that a PE sends; Then the public network multicast message that receives is reduced; The public network multicast message is reduced to the private network multicast message, according to its MVRF the private network multicast message is forwarded in the 2nd VPN then.

In the present embodiment, the MT between a PE and the 2nd PE can be any MT that is present between a PE and the 2nd PE.For example, if a PE and the 2nd PE belong to the 3rd VPN, then will have the MT of the MD of correspondence the 3rd VPN between a PE and the 2nd PE, then a PE can send to the 2nd PE with the public network multicast message through this MT.

If do not have any MT between a PE and the 2nd PE, then a PE can set up a MT earlier with the 2nd PE, through newly-built MT the public network multicast message is sent to the 2nd PE then.

In the present embodiment; The one PE is through the public network multicast address of MD under the 2nd PE of configuration the 2nd VPN under its MVRF; After receiving the private network multicast message that sends to the 2nd VPN, the private network multicast message of a VPN is encapsulated as the public network multicast message that destination address is the multicast address of MD under the 2nd PE; Send the 2nd PE through the Multicast Tunnel between a PE and the 2nd PE then; And then be forwarded to the 2nd VPN after by the 2nd PE the public network multicast message being reduced to the private network multicast message, realize striding the multicast of VPN, and need on a PE or the 2nd PE, not dispose unwanted VPN; Just need not set up Multicast Tunnel yet, practice thrift VPN and tunnel resource for the VPN of configuration.

The flow chart of the multicast forward method that Fig. 4 provides for another embodiment of the present invention.As shown in Figure 4, the method for present embodiment comprises:

Step 401, a PE be the public network multicast address of MD under configuration the 2nd PE under the MVRF of a PE in advance, and on a PE RP among the MD under configuration the 2nd PE.

In the present embodiment, under the MVRF of a PE, can dispose following information:

Xxx (config-vrf) #mdt default group_address: expression is based on enabling default MDT group under the VRF; Wherein, group_address comprises the multicast address of the MD that multicast address and the 2nd VPN of the MD that a VPN is corresponding is corresponding.Wherein, " xxx " representes set default prompt, for example can be set to the title of each company.

Xxx (config) #ip multicast-routing vrf vrf_name: expression is based on VRF multicast enabled agreement.

Xxx (config-if-type ID) #ip pim sparse-mode: expression public network interface enable multicast protocol.

Xxx (config-router) #neighbor ip-address remote-as asn-number: set up the IBGP session between the expression PE.

Xxx (config-router) #neighbor ip-address update-source interface-name: be used to indicate the interface of setting up bgp session, be used for public multicast route.

Xxx (config-router) #address-family ipv4 mdt: expression enables MDT address family.

Xxx (config-router-af) #neighbor ip-address activate: be illustrated in and activate bgp neighbor under this address family.

In addition, be provided with RP information to different VPN.For example, xxx (config) #ip pim [vrfvrf-name] rp-address rp-address [access_list]: expression is confirmed the RP position based on VRF.Wherein, based on different group addresss different RP can be set.In the present embodiment, during the public network multicast address of the MD under configuration the 2nd PE, disposed the RP corresponding simultaneously with this public network multicast address.

Step 402, a PE will be announced the multicast neighbor to a PE at the RP among the MD under the public network multicast address of MD under the 2nd PE of configuration under the MVRF of a PE and the 2nd PE that on a PE, disposes, and the multicast neighbor of a said PE comprises the 2nd PE.

Wherein, the multicast neighbor of a PE " xxx (config-router) #address-family ipv4mdt " this order and subsequent configuration just.

The one PE is at the public network multicast address that has disposed MD under the 2nd PE under its MVRF, and on a PE, disposed after the corresponding RP, and public network multicast address and the corresponding RP of MD under the 2nd PE that is disposed announced to its multicast neighbor.Wherein, a PE announces the binding relationship of its MVRF and public network multicast address to its neighbours' multicast, and in like manner, a PE also can receive the binding relationship of its multicast neighbor announcement.In the prior art, a PE and its multicast neighbor each other the purpose of the binding relationship through its MVRF and public network multicast address be for definite MT that whether sets up each other.In the present embodiment, a PE is to confirm whether set up one of factor of MT each other with the binding relationship that its multicast neighbor is announced its MVRF and public network multicast address each other, in addition, also will consider whether there has been MT between a PE and its multicast neighbor.If its MVRF that announces each other according to a PE and its multicast neighbor and the binding relationship of public network multicast address are determined each other needs and set up MT, and when having had MT between a PE and its multicast neighbor, just no longer set up MT.Only determine each other needs and set up MT, and when not having MT between a PE and its multicast neighbor, just can set up MT at the binding relationship of its MVRF that announces each other according to a PE and its multicast neighbor and public network multicast address.For example; If the MVRF of a PE has bound the public network multicast address of the affiliated MD of the 2nd PE; And the MVRF of the 2nd PE has also bound the public network multicast address of the affiliated MD of a PE, and does not still have MT between a PE and the 2nd PE, then can set up MT between a PE and the 2nd PE; If the MVRF of a PE has bound the public network multicast address of the affiliated MD of the 2nd PE; And the MVRF of the 2nd PE has also bound the public network multicast address of the affiliated MD of a PE; But there has been MT between a PE and the 2nd PE, then can not set up MT again between a PE and the 2nd PE.

Concrete, a PE can find its multicast neighbor through bgp protocol, and through the binding relationship of bgp protocol to its multicast neighbor announcement MVRF and public network multicast address.

PE in step 403, the VPN receives the private network multicast message that the multicast source in the VPN sends, and the destination address of said private network multicast message is the private network multicast address of the 2nd VPN.

The public network multicast address of MD under the 2nd PE in the 2nd VPN that step 404, PE basis dispose under the MVRF of a PE in advance; The private network multicast message is carried out encapsulation process generate the public network multicast message, the destination address of said public network multicast message is the public network multicast address of MD under the 2nd PE.

Step 405, a PE through and the 2nd PE between MT the public network multicast message is sent to the 2nd PE so that the 2nd PE is forwarded in the 2nd VPN after the public network multicast message is reduced to the private network multicast message.

Above-mentioned steps 403-step 405 can repeat no more at this referring to the description of step 301-step 303.

Further, if when not having MT between a PE and the 2nd PE, a PE and the 2nd PE need set up MT.Wherein, a PE and the 2nd PE process of setting up MT is just set up the process of DMT.This is set up process and specifically comprises: a PE and the 2nd PE are root with the RP among the MD under the 2nd PE that on a PE, disposes respectively; Send (* to this RP; Default mdt) add message to set up RPT, " the default mdt " in this adding message is meant the public network multicast address of MD under the 2nd PE of configuration under the MVRF of a PE.Then, the RP under the 2nd PE that on a PE, disposes among the MD can be the source with a PE and the 2nd PE, sends the SPT that corresponding (S, default mdt) registration message forms correspondence to a PE and the 2nd PE respectively.Wherein, the address of the expression of " S " in the registration message the one PE or the address of the 2nd PE; " default mdt " in the registration message is meant the public network multicast address of MD under the 2nd PE of configuration under the MVRF of a PE.So just between a PE and the 2nd PE, set up MDT, also will set up a MT.

A kind of network diagram of the MD VPN that Fig. 5 provides for one embodiment of the invention.As shown in Figure 5, the network of present embodiment comprises: three VPN are respectively VPNA, VPNB and VPNC.VPNA comprises multicast source 50, CE51, CE52 and PE53.VPNB comprises subscriber equipment 61, CE62 and PE63.VPNC comprises subscriber equipment 71, CE72 and PE63.PE53 is connected through RP60 with PE63, and PE53, PE63 and PE73 have constituted a MD.Wherein, PE73 belongs to another one VPN.

Suppose that the subscriber equipment 61 among the VPNB will be visited the video traffic that the multicast source 50 among the VPNA provides.The multicast forwarding flow process of then striding VPN is following:

The multicast address of the MD that VPNB is corresponding on configuration PE63 under the VRF of PE53.The RP of the corresponding VPNB of configuration on PE53.The multicast address of supposing the PE63 MD that upward VPNB is corresponding is 224.0.1.0.

The private network multicast message of multicast source 50 sends to PE53 through CE51.Source IP address and the purpose IP address of supposing the private network multicast message are respectively: 10.1.1.2 and 232.0.0.0.Wherein, 10.1.1.2 is the IP address of multicast source 50, and 232.0.0.0 is the private network multicast address of VPNB.

PE53 encapsulates the private network multicast message according to the multicast address of the pre-configured PE63 MD that upward VPNB is corresponding again, obtains the public network multicast message.Suppose source IP address and the purpose IP address difference 2.2.2.2 and the 224.0.1.0 of public network multicast message.Wherein, 2.2.2.2 is the loopback interface address of PE53, is used to set up the address of bgp neighbor, and 224.0.1.0 is the multicast address that PE63 goes up the corresponding MD of VPNB.

Then, PE53 encapsulates the GRE field again, is used for mark GRE encapsulation, informs that internal layer is IP.Then, PE53 carries out two layers of encapsulation to the public network multicast message, for example encapsulates target MAC (Media Access Control) address 01:00:5e:00:01:00.MAC Address 01:00:5e:00:01:00 is the corresponding multicast mac address of multicast address 224.0.1.0.

Then, PE53 through and PE63 between MT, along MDT between PE53 and the PE63 public network multicast message is sent to PE63.

After PE63 receives the public network multicast message, the public network multicast message is reduced, obtain source IP address and purpose IP address is respectively: the private network multicast message of 10.1.1.2 and 232.0.0.0 is forwarded to the private network multicast message in the VPNB.

In VPMB, the private network multicast message finally arrives subscriber equipment 61 through CE62.

Wherein, the private network multicast message of multicast source 50 comprised before CE51 sends to PE53: the process that subscriber equipment 61 order videos are professional.The professional process of subscriber equipment 61 order videos is: certain multicast channel of subscriber equipment 61 program requests, can send IGMP to gateway device and add message.IGMP adds message is transmitted to this VPNB through gateway device PE63.The RP that PE63 can continue in VPNB sends IGMP adding message.Concrete, PE63 can add message with this IGMP and be encapsulated in the gre tunneling message, forms the public network multicast message, is transmitted to corresponding PE53 through MT.PE53 can carry out decapsulation to this gre tunneling message, and is transmitted to the RP equipment among the VPNA according to VPN information, finally forms the RPT of this VPNA, thereby has realized that subscriber equipment 61 is to multicast source 50 order video services.

In sum; The multicast forward method that various embodiments of the present invention provide has solved the VPN quantity that on inlet or outlet PE, needs extra increase configuration; Effectively utilized limited precious resources; Made full use of the inner tunneling mechanism of setting up of same VPN, avoided effectively having utilized valuable tunnel resource owing to stride the quantity in the newly-increased tunnel of VPN function introducing.The multicast forward method that various embodiments of the present invention provide is disposed and implements simple relatively, understandable, has effectively reduced maintenance cost and workload.

The structural representation of the multicast apparatus that Fig. 6 provides for one embodiment of the invention.As shown in Figure 6, the device of present embodiment comprises: message receiver module 611, package module 621 and sending module 631.

Wherein, message receiver module 611, the multicast forwarding device that is used to receive present embodiment belongs to the private network multicast message that the multicast source in the VPN sends, and the destination address of said private network multicast message is the private network multicast address of the 2nd VPN.

Package module 621; Be connected with message receiver module 611; Be used for public network multicast group address according to MD under the multicast forwarding device in the 2nd VPN that the MVRF of the multicast forwarding device of present embodiment disposes down in advance; The private network multicast message that message receiver module 611 is received carries out encapsulation process generation public network multicast message, and the destination address of said public network multicast message is the public network multicast address of MD under the multicast forwarding device in the 2nd VPN.

Sending module 631; Be connected with package module 621; Be used for the public network multicast message that package module 621 is packaged into being sent to the multicast forwarding device in the 2nd VPN, so that the multicast forwarding device in the 2nd VPN is forwarded in the 2nd VPN after the public network multicast message is reduced to the private network multicast message through the multicast forwarding device of present embodiment and the MT between the multicast forwarding device in the 2nd VPN.

Dispose a VPN on the multicast forwarding device of present embodiment, but do not dispose the 2nd VPN.The multicast forwarding device of present embodiment belongs to different VPN with the interior multicast forwarding device of the 2nd VPN.

Each functional module of the multicast forwarding device of present embodiment can be used for carrying out the flow process of multicast forward method shown in Figure 3, and its concrete operation principle repeats no more, and sees the description of method embodiment for details.

Wherein, the multicast forwarding device in the multicast forwarding device of present embodiment or the 2nd VPN can be the PE in the MD VPN scheme, but is not limited thereto.

The multicast forwarding device of present embodiment; Public network multicast address through MD under the multicast forwarding device in pre-configured the 2nd VPN under its MVRF; Behind the private network multicast message in receiving a VPN at place; According to the public network multicast address of MD under the multicast forwarding device in the 2nd pre-configured VPN private network multicast message is encapsulated as the public network multicast message that destination address is the public network multicast address of MD under the multicast forwarding device in the 2nd VPN; Thereby do not dispose under the condition of a VPN not disposing on the multicast forwarding device of present embodiment on the 2nd VPN or the multicast forwarding device in the 2nd VPN; The public network multicast message is sent to the multicast group retransmission unit in the 2nd VPN, realized striding the multicast of VPN, and need on two multicast forwarding devices, not dispose unwanted VPN; Just need not set up Multicast Tunnel yet, practice thrift VPN and tunnel resource for the VPN of configuration.

The structural representation of the multicast forwarding device that Fig. 7 provides for another embodiment of the present invention.Present embodiment is based on realization embodiment illustrated in fig. 6, and is as shown in Figure 7, and the device of present embodiment also comprises: configuration module 641 and announcement module 651.

Wherein, Configuration module 641; Be connected with package module 621; The public network multicast group address of MD under the multicast forwarding device in the 2nd VPN that is used under the MVRF of package module 621, being disposed according to the multicast forwarding device of present embodiment; The private network multicast message that message receiver module 611 is received carries out encapsulation process and generates before the public network multicast message, in advance at the MVRF of the multicast forwarding device of the present embodiment public network multicast address of MD under the multicast forwarding device in configuration the 2nd VPN down, and on the multicast forwarding device of present embodiment, disposes the RP among the MD under the multicast forwarding device in the 2nd VPN.

Announcement module 651; Be connected with configuration module 641; The RP of MD announces the multicast neighbor to multicast forwarding device under the multicast forwarding device under the multicast forwarding device in the 2nd VPN that is used for configuration module 641 is disposed under the MVRF of multicast forwarding device in the public network multicast address of MD and the 2nd VPN that on multicast forwarding device, disposes, and the multicast neighbor of said multicast forwarding device comprises the multicast forwarding device in the 2nd VPN.

The above-mentioned functions module can be used for carrying out the corresponding flow process in embodiment illustrated in fig. 4, and its concrete operation principle repeats no more, and sees the description of method embodiment for details.

Further, the sending module 631 of present embodiment comprises: first sends submodule 6311 and second sends submodule 6321.

Wherein, First sends submodule 6311; Be connected with package module 621; When being used between the multicast forwarding device of present embodiment and the multicast forwarding device in the 2nd VPN, having had MT, the public network multicast message that directly package module 621 is packaged into sends to the multicast forwarding device in the 2nd VPN through the MT that has existed, so that the multicast forwarding device in the 2nd VPN is forwarded in the 2nd VPN after the public network multicast message is reduced to the private network multicast message.

Second sends submodule 6321; Be connected with package module 621; When being used between the multicast forwarding device of present embodiment and the multicast forwarding device in the 2nd VPN, not having MT; With the newly-built MT of the multicast forwarding device in the 2nd VPN, and the public network multicast message that package module 621 is packaged into sent to the multicast forwarding device in the 2nd VPN through newly-built MT, so that the multicast forwarding device in the 2nd VPN is forwarded in the 2nd VPN after this public network multicast message is reduced to the private network multicast message.

Further; Second of present embodiment sends the RP transmission (* that submodule 6321 specifically is used for MD under the multicast forwarding device in the 2nd VPN that disposes on the multicast forwarding device at present embodiment; The public network multicast address of MD under the multicast forwarding device in the 2nd VPN) adds message to set up RPT; And be received in (the S that the RP among the MD sends under the multicast forwarding device in the 2nd VPN that disposes on the multicast forwarding device of present embodiment; The public network multicast address of MD under the multicast forwarding device in the 2nd VPN) registration message to be setting up SPT, thereby between the multicast forwarding device of present embodiment and the multicast forwarding device in the 2nd VPN, sets up new MT.Wherein, S is the address of the multicast forwarding device of present embodiment.

The multicast forwarding device of present embodiment; Be implemented on the multicast forwarding device under the multicast forwarding device in pre-configured the 2nd VPN public network multicast address of MD and RP correspondingly through configuration module and announcement module, lay the foundation between the multicast forwarding device of present embodiment and the multicast forwarding device in the 2nd VPN, setting up Multicast Tunnel.

The structural representation of the multicast forwarding device that Fig. 8 provides for further embodiment of this invention.Present embodiment is based on realization embodiment illustrated in fig. 7; The multicast forwarding device of present embodiment not only can be used as the device of multicast source place VPN; Be responsible for the private network multicast message in the requestor's forwarding multicasting source in another VPN; The multicast forwarding device of present embodiment can also belong to the device in the VPN as multicast request person, the private network multicast message that belongs to multicast request from the multicast source of the device forwarding in the VPN to multicast source forwarding multicasting requestor and responsible receiving group source.The multicast forwarding device that is present embodiment can also be as the multicast forwarding device in the 2nd VPN.

As shown in Figure 8, the multicast apparatus of present embodiment also comprises: information receiving module 711 with set up module 721.

Wherein, The RP of the affiliated MD of multicast forwarding device of the present embodiment on the information receiving module 711, the public network multicast group address that is used for receiving MD under the multicast forwarding device of the MVRF that is configured in the multicast forwarding device in VPN present embodiment down of the multicast forwarding device announcement in the VPN and the multicast forwarding device that is configured in the VPN.

Set up module 721; Be connected with information receiving module 711; The RP that is used for MD under the multicast forwarding device of the present embodiment that disposes on the multicast forwarding device in a VPN that information receiving module 711 receives sends (*; The public network multicast group address of MD under the multicast forwarding device of present embodiment) adds message to set up RPT; And be received in the RP among the MD sends under the multicast forwarding device of the present embodiment that disposes on the multicast forwarding device in the VPN (the public network multicast address of MD under the S, the multicast forwarding device of present embodiment) registration message setting up SPT, thereby set up new Multicast Tunnel with the multicast forwarding device in the VPN.Wherein, S is the address of the multicast forwarding device of present embodiment.

Further, the multicast forwarding device of present embodiment also comprises: recovery module 731.

Recovery module 731 is used to receive the public network multicast message that the multicast forwarding device in the VPN sends, and is forwarded in the 2nd VPN after the public network multicast message is reduced to the private network multicast message.

Above-mentioned each functional module can be used for execution graph 3 or embodiment illustrated in fig. 4 in the corresponding flow process of multicast forwarding device in the 2nd VPN, its concrete operation principle repeats no more, and sees the description of method embodiment for details.

The multicast forwarding device of present embodiment can be the PE in the MD VPN scheme, but is not limited thereto.

The multicast forwarding device of present embodiment is as the device in the 2nd VPN; Match with the multicast forwarding device in the VPN, realized striding the multicast of VPN, and need not dispose unwanted VPN above that; Just unwanted Multicast Tunnel be need not set up yet, VPN and tunnel resource practiced thrift.

In this explanation; Multicast forwarding device and the multicast forwarding device in the 2nd VPN in the VPN that the embodiment of the invention provides can be separate; Be that the multicast forwarding device that the above embodiment of the present invention provides can only have the function of the multicast forwarding device in the VPN, also can only have the function of the multicast forwarding device in the 2nd VPN.

One embodiment of the invention provides a kind of network equipment, comprises arbitrary multicast forwarding device that the above embodiment of the present invention provides.

The network equipment of present embodiment can be the PE in the MD VPN scheme, but is not limited thereto.

The network equipment of present embodiment is owing to comprise the multicast forwarding device that the embodiment of the invention provides, and can be used for carrying out the flow process of the multicast forward method that the embodiment of the invention provides equally, can when realizing striding the multicast of VPN, practice thrift VPN and tunnel resource equally.

One of ordinary skill in the art will appreciate that: all or part of step that realizes above-mentioned each method embodiment can be accomplished through the relevant hardware of program command.Aforesaid program can be stored in the computer read/write memory medium.This program the step that comprises above-mentioned each method embodiment when carrying out; And aforesaid storage medium comprises: various media that can be program code stored such as ROM, RAM, magnetic disc or CD.

What should explain at last is: above each embodiment is only in order to explaining technical scheme of the present invention, but not to its restriction; Although the present invention has been carried out detailed explanation with reference to aforementioned each embodiment; Those of ordinary skill in the art is to be understood that: it still can be made amendment to the technical scheme that aforementioned each embodiment put down in writing, perhaps to wherein part or all technical characteristic are equal to replacement; And these are revised or replacement, do not make the scope of the essence disengaging various embodiments of the present invention technical scheme of relevant art scheme.

Claims

1. a multicast forward method is characterized in that, comprising:

2. multicast forward method according to claim 1; It is characterized in that; A said PE through and said the 2nd PE between Multicast Tunnel MT said public network multicast message is sent to said the 2nd PE comprise so that said the 2nd PE is reduced to said public network multicast message to be forwarded in said the 2nd VPN behind the said private network multicast message:

If had MT between a said PE and said the 2nd PE; A said PE directly sends to said the 2nd PE with said public network multicast message through the MT that has existed, so that said the 2nd PE is forwarded in said the 2nd VPN after said public network multicast message is reduced to said private network multicast message;

If do not have MT between a said PE and said the 2nd PE; A said PE and the newly-built MT of said the 2nd PE; And said public network multicast message sent to said the 2nd PE through newly-built MT, so that said the 2nd PE is forwarded in said the 2nd VPN after said public network multicast message is reduced to said private network multicast message.

3. multicast forward method according to claim 2; It is characterized in that; A said PE carries out comprising before the encapsulation process generation public network multicast message to said private network multicast message according to the public network multicast address of MD under the 2nd PE in said the 2nd VPN that under the MVRF of a said PE, disposes in advance:

A said PE is the public network multicast address of MD under said the 2nd PE of configuration under the MVRF of a said PE in advance, and on a said PE RP among the MD under said the 2nd PE of configuration;

A said PE will announce the multicast neighbor to a said PE at the RP among the MD under the public network multicast address of MD under the 2nd PE of configuration under the MVRF of a said PE and said the 2nd PE that on a said PE, disposes, and the multicast neighbor of a said PE comprises said the 2nd PE.

4. multicast forward method according to claim 3 is characterized in that, a said PE and the newly-built MT of said the 2nd PE comprise:

A said PE and said the 2nd the PE RP in MD under said the 2nd PE that on a said PE, disposes respectively send (the public network multicast address of MD under the *, said the 2nd PE) adding message to set up RPT;

A said PE and said the 2nd PE are received in a said PE respectively and go up (the S that the RP among the affiliated MD of said the 2nd PE that disposes sends; The public network multicast address of MD under said the 2nd PE) registration message is to set up SPT; Wherein, S is the address of a said PE or the address of said the 2nd PE.

5. a multicast forwarding device is characterized in that, comprising:

6. multicast forwarding device according to claim 5 is characterized in that, said sending module comprises:

First sends submodule; When being used for having had MT between the multicast forwarding device in said multicast forwarding device and said the 2nd VPN; Directly said public network multicast message is sent to the multicast forwarding device in said the 2nd VPN through the MT that has existed, so that the multicast forwarding device in said the 2nd VPN is forwarded in said the 2nd VPN after said public network multicast message is reduced to said private network multicast message;

Second sends submodule; When being used for not having MT between the multicast forwarding device in said multicast forwarding device and said the 2nd VPN; With the newly-built MT of multicast forwarding device in said the 2nd VPN; And said public network multicast message sent to the multicast forwarding device in said the 2nd VPN through newly-built MT, so that the multicast forwarding device in said the 2nd VPN is forwarded in said the 2nd VPN after said public network multicast message is reduced to said private network multicast message.

7. multicast forwarding device according to claim 6 is characterized in that, also comprises:

Configuration module; Be used in advance under the MVRF of said multicast forwarding device the public network multicast address of MD under the multicast forwarding device in said the 2nd VPN of configuration, and on said multicast forwarding device the RP among the MD under the multicast forwarding device in said the 2nd VPN of configuration;

Announcement module; The RP of MD announces the multicast neighbor to said multicast forwarding device under the multicast forwarding device under the multicast forwarding device in said the 2nd VPN that is used under the MVRF of said multicast forwarding device, disposing in the public network multicast address of MD and said the 2nd VPN that on said multicast forwarding device, disposes, and the multicast neighbor of said multicast forwarding device comprises the multicast forwarding device in said the 2nd VPN.

8. multicast forwarding device according to claim 7; It is characterized in that; Said second sends the RP transmission (* that submodule specifically is used for MD under the multicast forwarding device in said the 2nd VPN that on said multicast forwarding device, disposes; The public network multicast address of MD under the multicast forwarding device in said the 2nd VPN) adds message setting up RPT, and be received in the RP among the MD sends under the multicast forwarding device in said the 2nd VPN that disposes on the said multicast forwarding device (the public network multicast address of MD under the multicast forwarding device in the S, said the 2nd VPN) registration message to set up SPT; Wherein, S is the address of said multicast forwarding device.

9. according to claim 6 or 7 or 8 described multicast forwarding devices, it is characterized in that,

When said multicast forwarding device during as the multicast forwarding device in said the 2nd VPN, said multicast forwarding device also comprises:

The RP of the affiliated MD of said multicast forwarding device on the information receiving module, the public network multicast group address that is used for receiving MD under the MVRF that is configured in the multicast forwarding device in the said VPN said multicast forwarding device down of the multicast forwarding device announcement in the said VPN and the multicast forwarding device that is configured in the said VPN;

Set up module; The RP that is used for receiving to said information receiving module sends (*; The public network multicast group address of MD under the said multicast forwarding device) adds message setting up RPT, and be received in the RP among the MD sends under the said multicast forwarding device that disposes on the multicast forwarding device in the said VPN (the public network multicast address of MD under the S, said multicast forwarding device) registration message to set up SPT; Wherein, S is the address of said multicast forwarding device.

10. multicast forwarding device according to claim 9 is characterized in that, also comprises:

Recovery module is used to receive the public network multicast message that the multicast forwarding device in the said VPN sends, and is forwarded in said the 2nd VPN after said public network multicast message is reduced to the private network multicast message.

11. a network equipment is characterized in that, comprises each described multicast forwarding device of claim 5-10.