CN106487686B - SR forwarding entry generation method and device - Google Patents
SR forwarding entry generation method and device Download PDFInfo
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- CN106487686B CN106487686B CN201510543585.6A CN201510543585A CN106487686B CN 106487686 B CN106487686 B CN 106487686B CN 201510543585 A CN201510543585 A CN 201510543585A CN 106487686 B CN106487686 B CN 106487686B
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Abstract
The invention discloses a method for generating an SR forwarding entry, which comprises the following steps: a first SR node acquires a forwarding path from a home terminal to a second SR node; and when the SR related information of all the nodes in the forwarding path exists in the SR topology database of the local terminal, the first SR node generates an SR forwarding entry from the local terminal to the second SR node based on the forwarding path. The invention can solve the problem of bandwidth waste caused by wrong forwarding of the message in the mixed networking environment of the SR node and the non-SR node.
Description
Technical Field
The present invention relates to the field of network communication technologies, and in particular, to a method and an apparatus for generating SR forwarding entries.
Background
Segment Routing (SR) is a Routing technology based on a source address, and by superimposing a layer of node information affecting the forwarding of the existing shortest path outside a data packet, carried outside the data packet, an SR node receiving the data packet performs the shortest path forwarding according to the node information of the specified path.
In the hybrid networking environment shown in fig. 1, SR-enabled nodes include PE1, PE2, and P1, and P2 is a node that is not SR-enabled. When each SR node advertises mapping information between its SID (segment ID) and Prefix, since P2 does not support SR function, SID forwarding information to each SR node is not formed on P2, and for nodes that enable SR function, they learn each other to the SID of the other side through flooding information of IGP (Interior Gateway Protocol), and issue a label forwarding table according to the next hop information of Prefix; therefore, when a packet from a VPN (Virtual Private Network) needs to come in from PE1 and go out from PE2, PE1 performs MPLS (Multi-Protocol Label Switching) encapsulation forwarding, where the next hop is to P1, when the packet is forwarded to P1, the next hop of Prefix is to P2, the next hop and the outgoing interface of SID are also to P2, P2 receives the MPLS encapsulated packet, since P2 does not enable SR, and no Label-related forwarding entry exists, the packet is discarded by P2 without other mechanisms, and worse, when P2 has a forwarding entry with other meanings of the Label, P2 forwards the packet to an incorrect destination address. In the prior art, the problem of bandwidth waste caused by wrong forwarding of a message in a mixed networking environment of SR nodes and non-SR nodes exists.
Disclosure of Invention
The invention mainly aims to provide a method and a device for generating an SR forwarding entry, and aims to solve the problem of bandwidth waste caused by wrong forwarding of a message in a mixed networking environment of SR nodes and non-SR nodes.
In order to achieve the above object, the present invention provides a method for generating an SR forwarding entry, where the method for generating an SR forwarding entry includes:
a first SR node acquires a forwarding path from a home terminal to a second SR node;
and when the SR related information of all the nodes in the forwarding path exists in the SR topology database of the local terminal, the first SR node generates an SR forwarding entry from the local terminal to the second SR node based on the forwarding path.
Preferably, before the first SR node acquires a forwarding path from the home terminal to the second SR node, the method further includes:
when receiving the SR capability information and SR related information advertised by a second SR node, the first SR node stores the SR related information of the second SR node in the SR topology database.
Preferably, the SR-related information of the second SR node includes mapping information between the identification information of the second SR node and the SID, and the acquiring, by the first SR node, a forwarding path from the home terminal to the second SR node includes:
and the first SR node calculates a forwarding path from the local terminal to the second SR node based on the identification information advertised by the second SR node and the mapping information of the SID.
Preferably, the acquiring, by the first SR node, a forwarding path from the home terminal to the second SR node further includes:
and when receiving the SR capability information and the default label announced by the second SR node, the first SR node calculates a forwarding path from the local terminal to the default label by taking the second SR node as a destination.
Preferably, the acquiring, by the first SR node, a forwarding path from the home terminal to the second SR node further includes:
when receiving the Binding TLV information advertised by the second SR node, the first SR node calculates a forwarding path from the local terminal to the SID carried in the Binding TLV with the second SR node as a target, or calculates a forwarding path from the local terminal to the SID carried in the Binding TLV based on a preset path.
Preferably, the default label is specified by the second SR node based on user-entered configuration data or generated based on configuration defaults.
Preferably, the tag value of the default tag is a tag reserved value or a globally unique configuration value input by a user.
Preferably, the acquiring, by the first SR node, a forwarding path from the home terminal to the second SR node further includes:
the first SR node acquires a preset forwarding path from a local terminal to the second SR node, and the acquired preset forwarding path is used as the forwarding path from the first SR node to the second SR node.
Further, to achieve the above object, the present invention further provides an SR forwarding entry generating device, including:
the system comprises an acquisition module, a forwarding module and a forwarding module, wherein the acquisition module is used for acquiring a forwarding path from a first SR node to a second SR node where the acquisition module is located;
a generating module, configured to generate, based on the forwarding path, SR forwarding entries from the first SR node to the second SR node when SR-related information of all nodes in the forwarding path exists in the SR topology database of the first SR node.
Preferably, the SR forwarding entry generating device further includes a storage module, configured to store, when receiving SR capability information and SR related information advertised by a second SR node, the SR related information of the second SR node into the SR topology database.
Preferably, the SR-related information of the second SR node includes mapping information of the identification information and the SID of the second SR node, and the obtaining module is further configured to calculate a forwarding path from the first SR node to the second SR node based on the mapping information of the identification information and the SID advertised by the second SR node.
Preferably, the obtaining module is further configured to calculate, when receiving the SR capability information advertised by the second SR node and the default label, a forwarding path from the first SR node to the default label with the second SR node as a destination.
Preferably, the obtaining module is further configured to, when receiving the Binding TLV information advertised by the second SR node, calculate, with the second SR node as a destination, a forwarding path from the first SR node to the SID carried in the Binding TLV, or calculate, based on a preset path, a forwarding path from the first SR node to the SID carried in the Binding TLV.
Preferably, the default label is specified by the second SR node based on user-entered configuration data or generated based on configuration defaults.
Preferably, the tag value of the default tag is a tag reserved value or a globally unique configuration value input by a user.
Preferably, the obtaining module is further configured to obtain a preset forwarding path from the first SR node to the second SR node, and use the obtained preset forwarding path as a forwarding path from the first SR node to the second SR node.
The invention establishes an SR network topology by establishing an SR topology database in each SR node in a network in advance; when generating an SR forwarding entry from a home terminal to other SR nodes, an SR node firstly acquires a forwarding path from the home terminal to the other SR nodes, and generates the SR forwarding entry from the home terminal to the other SR nodes only when all nodes in the forwarding path exist in the SR network topology. Compared with the prior art, the invention avoids the message from entering the wrong forwarding path at the source, thereby solving the problem of bandwidth waste caused by the wrong forwarding of the message in the mixed networking environment of the SR node and the non-SR node.
Drawings
FIG. 1 is a schematic diagram of a networking environment;
fig. 2 is a flowchart illustrating a first embodiment of a SR forwarding entry generation method according to the present invention;
fig. 3 is a flowchart illustrating a second embodiment of the SR forwarding entry generation method according to the present invention;
fig. 4 is a functional block diagram of a SR forwarding entry generating apparatus according to a first embodiment of the present invention;
fig. 5 is a functional module diagram of an SR forwarding entry generating device according to a second embodiment of the present invention.
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Referring to fig. 2, in a first embodiment of the SR forwarding entry generation method of the present invention, the SR forwarding entry generation method includes:
s10, the first SR node obtains the forwarding path from the local terminal to the second SR node;
the SR forwarding entry generating method provided in this embodiment may be applied to SR forwarding entry generation of an SR node, for example, in a mixed networking environment of SR nodes and non-SR nodes, the SR node obtains a forwarding path from a home terminal to the target SR node, and if the forwarding path from the SR node to the target SR node includes the non-SR node, the SR node does not generate an SR forwarding entry to the target SR node; if the nodes in the forwarding path from the SR node to the target SR node are SR nodes, the SR node generates an SR forwarding entry to the target SR node and issues a forwarding table, so that the message can be prevented from entering an incorrect forwarding path at the source, and the problem of bandwidth waste caused by incorrect forwarding of the message in a mixed networking environment of the SR node and a non-SR node is solved.
In this embodiment, SR forwarding entry generation from a first SR node to a second SR node is described, where the first SR node and the second SR node may be any SR node in a network.
Specifically, before generating the SR forwarding entry to the second SR node, the first SR node first acquires a forwarding path from the home terminal to the second SR node. For example, the first SR node may calculate a forwarding path from the home terminal to the second SR node based on mapping information of a Prefix (here, the Prefix is identification information of the second SR node) advertised by the second SR node and the SID; a preset forwarding path from the first SR node to the second SR node may also be obtained, and the obtained preset forwarding path is used as a forwarding path from the first SR node to the second SR node; the first SR node may also calculate a forwarding path from the home terminal to the default label with the second SR node as a destination when the first SR node receives the SR capability information and the default label advertised by the second SR node.
S20, when SR-related information (including mapping information between unique identifier node address information such as Prefix or MAC address and SID of a node) of all nodes in the forwarding path exists in the SR topology database of the home terminal, the first SR node generates an SR forwarding entry from the home terminal to the second SR node based on the forwarding path.
After acquiring a forwarding path from a local terminal to the second SR node, the first SR node judges whether nodes on the forwarding path are SR nodes, and if yes, generates an SR forwarding entry from the local terminal to the second SR node. Specifically, the first SR node identifies whether SR-related information of all nodes on the forwarding path exists in an SR topology database of the home terminal, and when SR-related information of all nodes in the forwarding path exists in the SR topology database of the home terminal, the first SR node generates an SR forwarding entry from the home terminal to the second SR node based on the forwarding path.
It should be noted that, in this embodiment, each SR node in the network advertises SR capability information of the local terminal to other SR nodes to advertise that the SR node has SR capability, which is information content that needs to be advertised, and optionally, the SR node generally advertises SR-related information of the local terminal. Preferably, the SR-related information includes mapping information of SID and Prefix or mapping information of SID and System ID. An SR topology database is created in advance at each SR node and used for storing the related information of the SR announced by each SR node in the network so as to establish the SR network topology.
In the SR forwarding entry generation method provided in this embodiment, an SR topology database is created in advance at each SR node in a network to establish an SR network topology; when generating an SR forwarding entry from a home terminal to other SR nodes, an SR node firstly acquires a forwarding path from the home terminal to the other SR nodes, and generates the SR forwarding entry from the home terminal to the other SR nodes only when all nodes in the forwarding path exist in the SR network topology. Compared with the prior art, the invention avoids the message from entering the wrong forwarding path at the source, thereby solving the problem of bandwidth waste caused by the wrong forwarding of the message in the mixed networking environment of the SR node and the non-SR node.
Further, based on the first embodiment, a second embodiment of the SR forwarding entry generation method according to the present invention is provided, and referring to fig. 3, in this embodiment, before step S10, the method further includes:
s30, when receiving the SR capability information and SR related information advertised by the second SR node, the first SR node stores the SR related information of the second SR node in the SR topology database.
In this embodiment, when the first SR node receives the SR-related information advertised by the second SR node and receives the SR capability information advertised by the second SR node, the SR-related information advertised by the second SR node is stored as the SR-related information of the second SR node in the SR topology database of the local terminal.
Specifically, each SR node in the network advertises SR capability information and SR-related information of the home terminal through an IGP protocol extension TLV. Wherein the SR related information comprises the identification information of the SR node and the mapping information of the SID. Preferably, the SR node advertises its SR capability information through an SR capability sub-TLV.
It should be noted that, when the SR node runs different IGP (Interior Gateway Protocol) protocols, the selected identification information IS different, for example, when the SR node runs an OSPF Protocol, it selects its Router ID as the identification information, and when the SR node runs an IS-IS Protocol, it selects its System ID as the identification information.
Further, based on the second embodiment, a third embodiment of the SR forwarding entry generation method of the present invention is provided, in this embodiment, the SR-related information of the second SR node includes mapping information between identification information of the second SR node and a SID, and the step S10 includes:
and the first SR node calculates a forwarding path from the local terminal to the second SR node based on the identification information advertised by the second SR node and the mapping information of the SID.
In this embodiment, the SR-related information of the second SR node IS preferably mapping information between identification information of the second SR node and a SID, where the identification information of the second SR node depends on an IGP protocol operated by the second SR node, and when the second SR node operates an OSPF protocol, the second SR node selects its Router ID as the identification information, and when the second SR node operates an IS-IS protocol, the second SR node selects its System ID as the identification information.
Specifically, when the first SR node receives the SR capability information and SR related information advertised by the second SR node, the first SR node calculates a forwarding path from the home terminal to the second SR node based on the identification information and mapping information of the SID included in the SR related information, where the calculation of the forwarding path may be performed by referring to an existing segment routing technology, and is not described here any more.
Further, based on the first embodiment, a fourth embodiment of the SR forwarding entry generation method of the present invention is provided, in this embodiment, the step S10 further includes:
and when receiving the SR capability information and the default label announced by the second SR node, the first SR node calculates a forwarding path from the local terminal to the default label by taking the second SR node as a destination.
It should be noted that, the Segment Routing technology fully utilizes the existing MPLS (Multi-Protocol Label Switching) encapsulation technology, and a Segment Routing Header (Segment Routing Header) is carried in a packet Header of the existing MPLS network or an IPv6 packet Header. The MPLS packet header consists of 32bits (4 bytes), where a 20-bit label field and a 3-bit CoS field are used for priority indication of the packet. The stack bottom mark of 1bit is used for nesting operation of MPLS, and the TTL field of 8bits is used for TTL counting in the MPLS network. The segment routing technology is completely compatible and inherits the existing MPLS forwarding data plane, and the forwarding of the segment routing can be realized without modifying the message header of the MPLS. In MPLS data encapsulation, a segment list in an SR Header is described in a manner of a label stack, where the segment list includes an SID of each SR node on a forwarding path.
In draft-file-spring-Segment-Routing-LDP-interrupt-00, the interworking between LDP (Label Distribution Protocol) and SR is described, and the interworking between LDP and SR specifically involves SR Mapping advertisements of Segment Routing Mapping Server (SRMS) nodes and non-SR nodes. Since label mapping for LDP is automatically generated from IP, SID is also mapped from IP address. Therefore, when an SR label and an LDP label mapped by a PE (Provider Edge, network side Edge node) are searched for an incoming label and an outgoing label, a mapping can be directly formed according to the IP of the PE, and forwarding is formed according to whether the next hop is an SR neighbor or an LDP neighbor, as described in section 4.2:
P6's next-hop for the IGP route"PE3"is not SR capable(P7 does not advertise the SR capability)。However，P6 has an LDP label binding from that next-hop for the same FEC(e.g.LDP label 1037)。Hence，P6 swaps 103 for 1037 and forwards to P7。
in this embodiment, when the second SR node is an SRMS node that supports both SR and LDP, the second SR node is configured to distribute a virtual SID to a node that does not support SR. Meanwhile, the second SR node announces a default label to the second SR node, and the announcement of the default label is carried in a TLV in an extended mode, so that the message of which the label cannot be found is ensured to be forwarded by the second SR node.
Further, based on the first embodiment, a fifth embodiment of the SR forwarding entry generation method of the present invention is provided, and in this embodiment, the step S10 further includes:
when receiving the Binding TLV information advertised by the second SR node, the first SR node calculates a forwarding path from the local terminal to the SID carried in the Binding TLV with the second SR node as a target, or calculates a forwarding path from the local terminal to the SID carried in the Binding TLV based on a preset path.
In this embodiment, when the second SR node is an SRMS node that supports both SR and LDP, the second SR node is configured to distribute a virtual SID to a node that does not support SR. Specifically, the second SR node advertises, for a non-SR node, mapping information of a virtual SID and identification information of the non-SR node through a Binding TLV; when receiving the Binding TLV information announced by the second SR node, the first SR node calculates a forwarding path from the local terminal to the SID carried in the Binding TLV with the second node as a target, or calculates a forwarding path from the local terminal to the SID carried in the Binding TLV based on a preset path. The preset path is the shortest forwarding path from the first SR node to the second SR node. Preferably, the First SR node calculates a Shortest forwarding Path from the home terminal to the second SR node by using an SPF algorithm (Shortest Path First, also called Dijkstra algorithm), and takes the calculated Shortest forwarding Path as the preset Path. Based on the description of the foregoing technical solution, as can be understood by those skilled in the art, when the first SR node receives a packet whose target SID is a virtual SID, the first SR node forwards the packet to the second SR node based on the generated forwarding entry from the home terminal to the second SR node, and the second SR node is responsible for forwarding the packet to a non-SR node corresponding to the virtual SID.
Further, based on the fourth or fifth embodiment, a sixth embodiment of the SR forwarding entry generation method of the present invention is proposed, in which in this embodiment, the default label is specified by the second SR node based on configuration data input by a user or generated based on configuration defaults.
Further, the label value of the default label is a label reserved value or a globally unique configuration value input by a user.
Note that, in the prior art, a tag value between 0 and 15 is used as a tag reservation value for a special purpose. In this embodiment, the default label is uniformly specified by a user and identified by all MPLS forwarding nodes, and preferably, a label value of the default label is a label reservation value or a globally unique configuration value input by the user.
Further, based on the first embodiment, a seventh embodiment of the SR forwarding entry generation method of the present invention is provided, in this embodiment, the step S10 further includes:
the first SR node acquires a preset forwarding path from a local terminal to the second SR node, and the acquired preset forwarding path is used as the forwarding path from the first SR node to the second SR node.
In this embodiment, the preset forwarding path is generated by the first SR node based on configuration data of a user, so as to ensure that the preset forwarding path is used as the forwarding path from the first SR node to the second SR node when the forwarding path from the first SR node to the second SR node is not obtained by using any of the technical solutions described in the foregoing embodiments of the present invention.
Referring to fig. 4, in a first embodiment of the SR forwarding entry generating device according to the present invention, the SR forwarding entry generating device includes:
an obtaining module 10, configured to obtain a forwarding path from a first SR node where the forwarding path is located to a second SR node;
the SR forwarding entry generating device provided in this embodiment may be applied to SR forwarding entry generation of an SR node, for example, in a hybrid networking environment of SR nodes and non-SR nodes, the SR forwarding entry generating device is built in the SR node and operates, the SR node obtains a forwarding path from a local terminal to the target SR node, and if the forwarding path from the SR node to the target SR node includes the non-SR node, the SR node may not generate an SR forwarding entry to the target SR node; if the nodes in the forwarding path from the SR node to the target SR node are SR nodes, the SR node generates an SR forwarding entry to the target SR node and issues a forwarding table, so that the message can be prevented from entering an incorrect forwarding path at the source, and the problem of bandwidth waste caused by incorrect forwarding of the message in a mixed networking environment of the SR node and a non-SR node is solved.
In this embodiment, an SR forwarding entry generating device is built in a first SR node to operate, and SR forwarding entry generation from the first SR node to a second SR node is described, where the first SR node and the second SR node may be any SR node in a network.
Specifically, before generating the SR forwarding entry to the second SR node, the first SR node first acquires a forwarding path from the home terminal to the second SR node. For example, the first SR node may calculate a forwarding path from the home terminal to the second SR node based on mapping information of a Prefix (here, the Prefix is identification information of the second SR node) advertised by the second SR node and the SID; a preset forwarding path from the first SR node to the second SR node may also be obtained, and the obtained preset forwarding path is used as a forwarding path from the first SR node to the second SR node; the first SR node may also calculate a forwarding path from the home terminal to the default label with the second SR node as a destination when the first SR node receives the SR capability information and the default label advertised by the second SR node.
A generating module 20, configured to generate an SR forwarding entry from the first SR node to the second SR node based on the forwarding path when SR-related information (including mapping information that can uniquely identify node address information and SID, such as Prefix or MAC address, of all nodes in the forwarding path) exists in the SR topology database of the first SR node.
After acquiring a forwarding path from a local terminal to the second SR node, the first SR node judges whether nodes on the forwarding path are SR nodes, and if yes, generates an SR forwarding entry from the local terminal to the second SR node. Specifically, the first SR node identifies whether SR-related information of all nodes on the forwarding path exists in an SR topology database of the home terminal, and when SR-related information of all nodes in the forwarding path exists in the SR topology database of the home terminal, the first SR node generates an SR forwarding entry from the home terminal to the second SR node based on the forwarding path.
It should be noted that, in this embodiment, each SR node in the network advertises SR capability information of the local terminal to other SR nodes to advertise that the SR node has SR capability, which is information content that needs to be advertised, and optionally, the SR node generally advertises SR-related information of the local terminal. Preferably, the SR-related information includes mapping information of SID and Prefix or mapping information of SID and System ID. An SR topology database is created in advance at each SR node and used for storing the related information of the SR announced by each SR node in the network so as to establish the SR network topology.
The SR forwarding entry generating device provided in this embodiment creates an SR topology database in advance at each SR node in a network, so as to establish an SR network topology; when generating an SR forwarding entry from a home terminal to other SR nodes, an SR node firstly acquires a forwarding path from the home terminal to the other SR nodes, and generates the SR forwarding entry from the home terminal to the other SR nodes only when all nodes in the forwarding path exist in the SR network topology. Compared with the prior art, the invention avoids the message from entering the wrong forwarding path at the source, thereby solving the problem of bandwidth waste caused by the wrong forwarding of the message in the mixed networking environment of the SR node and the non-SR node.
Further, based on the first embodiment, a second embodiment of the SR forwarding entry generating device of the present invention is provided, and referring to fig. 5, in this embodiment, the SR forwarding entry generating device further includes a storage module 30, configured to store, when receiving SR capability information and SR related information advertised by a second SR node, the SR related information of the second SR node into the SR topology database.
In this embodiment, when the first SR node receives the SR-related information advertised by the second SR node and receives the SR capability information advertised by the second SR node, the SR-related information advertised by the second SR node is stored as the SR-related information of the second SR node in the SR topology database of the local terminal.
Specifically, each SR node in the network advertises SR capability information and SR-related information of the home terminal through an IGP protocol extension TLV. Wherein the SR related information comprises the identification information of the SR node and the mapping information of the SID. Preferably, the SR node advertises its SR capability information through an SR capability sub-TLV.
It should be noted that, when the SR node runs different IGP (Interior Gateway Protocol) protocols, the selected identification information IS different, for example, when the SR node runs an OSPF Protocol, it selects its Router ID as the identification information, and when the SR node runs an IS-IS Protocol, it selects its System ID as the identification information.
Further, based on the second embodiment, a third embodiment of the SR forwarding entry generating device of the present invention is provided, in this embodiment, the SR-related information of the second SR node includes mapping information of identification information and a SID of the second SR node, and the obtaining module 10 is further configured to calculate a forwarding path from the first SR node to the second SR node based on the mapping information of the identification information and the SID advertised by the second SR node.
In this embodiment, the SR-related information of the second SR node IS preferably mapping information between identification information of the second SR node and a SID, where the identification information of the second SR node depends on an IGP protocol operated by the second SR node, and when the second SR node operates an OSPF protocol, the second SR node selects its Router ID as the identification information, and when the second SR node operates an IS-IS protocol, the second SR node selects its System ID as the identification information.
Specifically, when the first SR node receives the SR capability information and SR related information advertised by the second SR node, the first SR node calculates a forwarding path from the home terminal to the second SR node based on the identification information and mapping information of the SID included in the SR related information, where the calculation of the forwarding path may be performed by referring to an existing segment routing technology, and is not described here any more.
Further, based on the first embodiment, a fourth embodiment of the SR forwarding entry generating device of the present invention is provided, in this embodiment, the obtaining module 10 is further configured to calculate, when receiving the SR capability information and the default label advertised by the second SR node, a forwarding path from the first SR node to the default label with the second SR node as a destination.
It should be noted that, the Segment Routing technology fully utilizes the existing MPLS (Multi-Protocol Label Switching) encapsulation technology, and a Segment Routing Header (Segment Routing Header) is carried in a packet Header of the existing MPLS network or an IPv6 packet Header. The MPLS packet header consists of 32bits (4 bytes), where a 20-bit label field and a 3-bit CoS field are used for priority indication of the packet. The stack bottom mark of 1bit is used for nesting operation of MPLS, and the TTL field of 8bits is used for TTL counting in the MPLS network. The segment routing technology is completely compatible and inherits the existing MPLS forwarding data plane, and the forwarding of the segment routing can be realized without modifying the message header of the MPLS. In MPLS data encapsulation, a segment list in an SR Header is described in a manner of a label stack, where the segment list includes an SID of each SR node on a forwarding path.
In draft-file-spring-Segment-Routing-LDP-interrupt-00, the interworking between LDP (Label Distribution Protocol) and SR is described, and the interworking between LDP and SR specifically involves SR Mapping advertisements of Segment Routing Mapping Server (SRMS) nodes and non-SR nodes. Since label mapping for LDP is automatically generated from IP, SID is also mapped from IP address. Therefore, when an SR label and an LDP label mapped by a PE (Provider Edge, network side Edge node) are searched for an incoming label and an outgoing label, a mapping can be directly formed according to the IP of the PE, and forwarding is formed according to whether the next hop is an SR neighbor or an LDP neighbor, as described in section 4.2:
P6's next-hop for the IGP route"PE3"is not SR capable(P7 does not advertise the SR capability)。However，P6 has an LDP label binding from that next-hop for the same FEC(e.g.LDP label 1037)。Hence，P6 swaps 103 for 1037 and forwards to P7。
in this embodiment, when the second SR node is an SRMS node that supports both SR and LDP, the second SR node is configured to distribute a virtual SID to a node that does not support SR. Meanwhile, the second SR node announces a default label to the second SR node, and the announcement of the default label is carried in a TLV in an extended mode, so that the message of which the label cannot be found is ensured to be forwarded by the second SR node.
Further, based on the first embodiment, a fifth embodiment of the SR forwarding entry generating device of the present invention is provided, in this embodiment, the obtaining module 10 is further configured to, when receiving the Binding TLV information advertised by the second SR node, calculate, with the second SR node as a destination, a forwarding path from the first SR node to a SID carried in the Binding TLV, or calculate, based on a preset path, a forwarding path from the first SR node to a SID carried in the Binding TLV.
In this embodiment, when the second SR node is an SRMS node that supports both SR and LDP, the second SR node is configured to distribute a virtual SID to a node that does not support SR. Specifically, the second SR node advertises, for a non-SR node, mapping information of a virtual SID and identification information of the non-SR node through a Binding TLV; when receiving the Binding TLV information announced by the second SR node, the first SR node calculates a forwarding path from the local terminal to the SID carried in the Binding TLV with the second node as a target, or calculates a forwarding path from the local terminal to the SID carried in the Binding TLV based on a preset path. The preset path is the shortest forwarding path from the first SR node to the second SR node. Preferably, the First SR node calculates a Shortest forwarding Path from the home terminal to the second SR node by using an SPF algorithm (Shortest Path First, also called Dijkstra algorithm), and takes the calculated Shortest forwarding Path as the preset Path. Based on the description of the foregoing technical solution, as can be understood by those skilled in the art, when the first SR node receives a packet whose target SID is a virtual SID, the first SR node forwards the packet to the second SR node based on the generated forwarding entry from the home terminal to the second SR node, and the second SR node is responsible for forwarding the packet to a non-SR node corresponding to the virtual SID.
Further, based on the fourth or fifth embodiment, a sixth embodiment of the SR forwarding entry generating device of the present invention is proposed, in which the default label is specified by the second SR node based on configuration data input by a user or generated based on configuration default.
Further, the label value of the default label is a label reserved value or a globally unique configuration value input by a user.
Note that, in the prior art, a tag value between 0 and 15 is used as a tag reservation value for a special purpose. In this embodiment, the default label is uniformly specified by a user and identified by all MPLS forwarding nodes, and preferably, a label value of the default label is a label reservation value or a globally unique configuration value input by the user.
Further, based on the first embodiment, a seventh embodiment of the SR forwarding entry generating device in the present invention is provided, in this embodiment, the obtaining module 10 is further configured to obtain a preset forwarding path from the first SR node to the second SR node, and use the obtained preset forwarding path as the forwarding path from the first SR node to the second SR node.
In this embodiment, the preset forwarding path is generated by the first SR node based on configuration data of a user, so as to ensure that the preset forwarding path is used as the forwarding path from the first SR node to the second SR node when the forwarding path from the first SR node to the second SR node is not obtained by using any of the technical solutions described in the foregoing embodiments of the present invention.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.
Claims (14)
1. A method for generating an SR forwarding entry, the method comprising:
a first SR node acquires a forwarding path from a home terminal to a second SR node;
when the SR related information of all the nodes in the forwarding path exists in the SR topology database of the local terminal, the first SR node generates an SR forwarding entry from the local terminal to the second SR node based on the forwarding path;
before the first SR node acquires a forwarding path from the home terminal to the second SR node, the method further includes:
when receiving the SR capability information and SR related information advertised by a second SR node, the first SR node stores the SR related information of the second SR node in the SR topology database.
2. The SR forwarding entry generating method of claim 1, wherein the SR-related information of the second SR node includes mapping information of an SID and identification information of the second SR node, and the acquiring, by the first SR node, a forwarding path from the home terminal to the second SR node includes:
and the first SR node calculates a forwarding path from the local terminal to the second SR node based on the identification information advertised by the second SR node and the mapping information of the SID.
3. The SR forwarding entry generation method of claim 1 wherein the first SR node obtaining the forwarding path from the home terminal to the second SR node further comprises:
and when receiving the SR capability information and the default label announced by the second SR node, the first SR node calculates a forwarding path from the local terminal to the default label by taking the second SR node as a destination.
4. The SR forwarding entry generation method of claim 1 wherein the first SR node obtaining the forwarding path from the home terminal to the second SR node further comprises:
when receiving the Binding TLV information advertised by the second SR node, the first SR node calculates a forwarding path from the local terminal to the SID carried in the Binding TLV with the second SR node as a target, or calculates a forwarding path from the local terminal to the SID carried in the Binding TLV based on a preset path.
5. The SR forwarding entry generation method of claim 3 wherein the default label is specified by the second SR node based on user-entered configuration data or generated based on a configuration default.
6. The SR forwarding entry generating method of claim 3, wherein the label value of the default label is a label reservation value or a globally unique configuration value input by a user.
7. The SR forwarding entry generation method of claim 1 wherein the first SR node obtaining the forwarding path from the home terminal to the second SR node further comprises:
the first SR node acquires a preset forwarding path from a local terminal to the second SR node, and the acquired preset forwarding path is used as a forwarding path from the first SR node to the second SR node; the preset forwarding path is generated by the first SR node based on configuration data of a user.
8. An SR forwarding entry generating apparatus, comprising:
the system comprises an acquisition module, a forwarding module and a forwarding module, wherein the acquisition module is used for acquiring a forwarding path from a first SR node to a second SR node where the acquisition module is located;
a generating module, configured to generate, based on the forwarding path, SR forwarding entries from the first SR node to the second SR node when SR-related information of all nodes in the forwarding path exists in an SR topology database of the first SR node;
the SR forwarding entry generating device further includes a storage module, configured to store, when receiving SR capability information and SR related information advertised by a second SR node, the SR related information of the second SR node in the SR topology database.
9. The SR forwarding entry generating apparatus of claim 8, wherein the SR-related information of the second SR node comprises mapping information of identification information and SID of the second SR node, and the obtaining module is further configured to calculate a forwarding path from the first SR node to the second SR node based on the mapping information of identification information and SID advertised by the second SR node.
10. The SR forwarding entry generating apparatus of claim 8, wherein the obtaining module is further configured to calculate a forwarding path from the first SR node to a default label for the purpose of the second SR node when receiving SR capability information advertised by the second SR node and the default label.
11. The SR forwarding entry generating device of claim 8, wherein the obtaining module is further configured to, when receiving the Binding TLV information advertised by the second SR node, calculate a forwarding path from the first SR node to the SID carried in the Binding TLV for the purpose of the second SR node, or calculate a forwarding path from the first SR node to the SID carried in the Binding TLV based on a preset path.
12. The SR forwarding entry generation apparatus of claim 10 wherein the default label is specified by the second SR node based on user-entered configuration data or generated based on a configuration default.
13. The SR forwarding entry generating apparatus of claim 10 wherein the label value of the default label is a label reservation value or a user-entered globally unique configuration value.
14. The SR forwarding entry generating device of claim 8, wherein the obtaining module is further configured to obtain a preset forwarding path from the first SR node to the second SR node, and use the obtained preset forwarding path as the forwarding path from the first SR node to the second SR node; the preset forwarding path is generated by the first SR node based on configuration data of a user.
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| CN110300061A (en) * | 2018-03-23 | 2019-10-01 | 中兴通讯股份有限公司 | A kind of method, equipment and storage medium for noticing binding information |
| CN109067657B (en) * | 2018-08-24 | 2021-03-26 | 新华三技术有限公司 | Message processing method and device |
| WO2020042018A1 (en) * | 2018-08-29 | 2020-03-05 | 华为技术有限公司 | Method for detecting bandwidth and detection device |
| CN110971433B (en) * | 2018-09-29 | 2022-02-22 | 华为技术有限公司 | Method, device and system for acquiring SRv6 tunnel information |
| CN109039903B (en) * | 2018-10-18 | 2021-01-26 | 新华三技术有限公司 | Route determining method, device and machine-readable storage medium |
| CN109347740B (en) * | 2018-11-19 | 2022-03-01 | 新华三技术有限公司 | Message forwarding method and device |
| CN111464441A (en) * | 2019-01-21 | 2020-07-28 | 华为技术有限公司 | Communication method and device |
| CN111464440A (en) * | 2019-01-21 | 2020-07-28 | 华为技术有限公司 | Communication method and device |
| CN112583711A (en) * | 2019-09-27 | 2021-03-30 | 华为技术有限公司 | Message processing method and device |
| CN116634459A (en) * | 2019-10-15 | 2023-08-22 | 华为技术有限公司 | Method and equipment for confirming telemetry capability of stream following information |
| CN111130811B (en) * | 2019-12-24 | 2022-09-30 | 广东省新一代通信与网络创新研究院 | Broadband access method based on segment routing, BRAS controller and data center system |
| CN113765791B (en) * | 2020-06-02 | 2023-01-13 | 华为技术有限公司 | Method, node and system for determining processing capacity |
| CN112671652B (en) * | 2020-11-26 | 2022-08-30 | 新华三技术有限公司 | Message forwarding method and device |
| CN115834480A (en) * | 2021-09-16 | 2023-03-21 | 华为技术有限公司 | Method, device, system and storage medium for acquiring capability and sending capability information |
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