CN116781594A - Message forwarding method and device - Google Patents

Abstract

The application provides a message forwarding method and equipment, wherein the method comprises the following steps: receiving a message with SRv; SRv6 the external destination IP address of the message is the mirror SID of the local configuration; terminating the mirror SID of the outer layer SRH header of SRv through the mirror termination table entry and looping back; terminating the virtual private network VPN SID of the protected tail node of the outer layer SRH header of the looped-back SRv message through the remote termination table entry, stripping the outer layer SRH header and looping back again; stripping the inner layer SRH head of the re-looped SRv message to obtain an inner layer IP message; identifying VPN examples which belong to the IP messages according to the inner layer; and searching an output port of a destination IP address of the inner layer IP message in the identified VPN example, and sending the IP address.

Description

Message forwarding method and device

Technical Field

The present application relates to communication technologies, and in particular, to a method and an apparatus for forwarding a message.

Background

SRv6 TE Policy is SRv-based SR TE Policy (Segment Routing Traffic Engineering Policy ), which provides a flexible forwarding path selection method that can meet different forwarding requirements of users. When a plurality of paths exist between the source node and the destination node of the Segment Routing network, SRv TE Policy is reasonably utilized to select a forwarding path, so that an administrator can conveniently manage and plan the network, and forwarding pressure of network equipment can be effectively relieved.

Under SRv TE Policy network architecture, the message encapsulation format is sequentially from outside to inside an outer layer IPv6 header, SRH (Segment Routing Traffic) header and an original three-layer IP message. When the PE node finds that the path to the tail node needs to send SRv to the path to the backup tail node of the tail node, it needs to add an SRH header indicating the path to the backup tail node before the SRH header of SRv.

However, due to the performance limitation of the switch chip, when the backup tail node receives the SRv message with the twice SRH header, the newly added outer SID can only be terminated, but the original SRH header of the inner layer cannot be unpacked, and the original three-layer IP message cannot be obtained for forwarding.

Disclosure of Invention

The application aims to provide a message forwarding method and equipment, which enable a backup tail node to realize two-layer SRH head termination.

In order to achieve the above object, the present application provides a method for forwarding a message, which includes: receiving a message with SRv; the outer layer destination IP address of SRv message is the mirror image SID of local configuration, SRv6 message has double-layer SRH head and SL of outer layer SRH head is equal to penultimate jump; SL for inner SRH equals last hop; terminating the mirror SID of the outer layer SRH header of SRv through the mirror termination table entry and looping back; terminating the virtual private network VPN SID of the protected tail node of the outer layer SRH header of the looped-back SRv message through the remote termination table entry, stripping the outer layer SRH header and looping back again; stripping the inner layer SRH head of the re-looped SRv message to obtain an inner layer IP message; identifying VPN examples which belong to the IP messages according to the inner layer; and searching an output port of a destination IP address of the inner layer IP message in the identified VPN example, and sending the IP address.

In order to achieve the above object, the present application also provides a message forwarding device, which includes a processor and a memory; the memory is used for storing processor executable instructions; wherein the processor is configured to execute the following operations by executing processor-executable instructions in the memory: receiving a message with SRv; the outer layer destination IP address of SRv message is the mirror image SID of local configuration, SRv6 message has double-layer SRH head and SL of outer layer SRH head is equal to penultimate jump; SL for inner SRH equals last hop; terminating the mirror SID of the outer layer SRH header of SRv through the mirror termination table entry and looping back; terminating the virtual private network VPN SID of the protected tail node of the outer layer SRH header of the looped-back SRv message through the remote termination table entry, stripping the outer layer SRH header and looping back again; stripping the inner layer SRH head of the re-looped SRv message to obtain an inner layer IP message; identifying VPN examples which belong to the IP messages according to the inner layer; and searching an output port of a destination IP address of the inner layer IP message in the identified VPN example, and sending the IP address.

The application has the advantages that when the backup tail node provides backup forwarding for the protected tail node, the double-layer SRH head under SRv TE architecture can be terminated, and the inner-layer IP message is sent to the target equipment.

Drawings

FIG. 1 is a flow chart of a message forwarding embodiment provided by the present application;

fig. 2 is a schematic diagram of tail node protection under a SRv TE Policy network architecture provided in the present application;

fig. 3 is a schematic diagram of a SRv message forwarding embodiment of backup tail node forwarding provided in the present application;

fig. 4 is a schematic diagram of another embodiment of forwarding a SRv message by a backup tail node according to the present application;

fig. 5 is a schematic diagram of an embodiment of a packet forwarding device provided in the present application.

Detailed Description

A plurality of examples shown in the drawings will be described in detail. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the application. Well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the examples.

The term "comprising" as used in the terminology includes, but is not limited to; the term "comprising" means including but not limited to; the terms "above," "within," and "below" encompass the present number; the terms "greater than", "less than" mean that the number is not inclusive. The term "based on" means based at least in part on a portion thereof.

FIG. 1 is a flow chart of a message forwarding embodiment provided by the present application; the method comprises the following steps:

step 101, receiving a message with SRv;

the outer layer destination IP address of SRv message is the mirror image SID of local configuration, SRv6 message has double-layer SRH head and SL of outer layer SRH head is equal to penultimate jump; SL for inner SRH equals last hop;

step 102, terminating the mirror SID of the outer layer SRH header of SRv by a mirror termination table entry and looping back;

step 103, terminating the virtual private network VPN SID of the protected tail node of the outer layer SRH header of the looped-back SRv message through the remote termination table entry, peeling the outer layer SRH header and looping back again;

step 104, stripping the inner layer SRH head of the re-looped SRv message to obtain an inner layer IP message;

step 105, identifying VPN examples which belong to the IP message according to the inner layer;

and 106, searching the output port of the destination IP address of the inner layer IP message in the identified VPN example, and sending the IP address.

The embodiment of fig. 1 has the beneficial effects that when the backup tail node provides backup forwarding for the protected tail node, the dual-layer SRH header under the SRv TE architecture can be terminated, and the inner-layer IP message is sent to the destination device.

Fig. 2 is a schematic diagram of tail node protection under a SRv TE Policy network architecture provided in the present application; PE201-PE207 enables SRv with locators of 1:64, 2:64, 3:64, 4:64, 5:64, 6:64, 7:64. PE201-PE207 each generate a locator route that is diffused outward through the IGP. CE208 dual homing has access to PE206 and PE207; PE206 and PE207 are configured with different VPNSIDs of the same VPN instance, namely SID 1:600 and SID 1:700, belonging to the End.DT6SID.

CE208 issues a normal IPv6 route to PE206, and PE206, upon receiving the route from the designated interface, converts to a VPNv6 route and then issues it to PE 201. The published VPNv6 route would carry a VPN SID6: 100. After receiving the route, PE201 performs route intersection, where the route intersection is performed to a VPN instance to which CE (Customer Edge device) accessed by PE201 belongs, and then CE device (not shown) accessed by PE201 learns the route of CE208.

PE201 receives IP message 300 from local CE to CE208, and queries VPN SID6 in VPN example routing table according to destination IP address of IP message to CE 203: 100, PE201 encapsulates IP message into SRv message; wherein, the segment list (segment list) in the SRH header is sequentially and inversely stacked in the SRH header according to the sequence of forwarding paths PE201- > PE202- > PE204- > PE206 for data encapsulation; the SIP of the IPv6 header is SID 1:1 of PE 201.

After the SRv message encapsulated by the PE201 is forwarded by the PE202, the SRv message 20 is sent to the PE204.

PE204 receives SRv message 20 and modifies SL (segment left) =1 to sl=0 in SRH header 302; the destination IP address of the IPv6 header 301 header is modified to be 100:100: SRv6 message 20 is modified to SRv6 message 21.

When the PE204 determines that the path reaching the PE206 is not reachable, the mirror SID 7:1 is used for packaging, a backup path SRH header 303 is added, in the SRH header 303 of the SRv message 21, SL=2 and segment list is subjected to data packaging according to reverse sequence stacking of the backup path PE204- > PE205- > PE207, the destination IP address of the IPv6 header 301 header is modified from VPN SID 6:100 to SID 5:1, the SRv6 message 21 is modified into SRv6 message 22, and SRv message 22 is sent to the PE205. The mirror SID is a SID of a varying end.dt6 SID type.

PE205 modifies sl=2 of the SRH303 header to sl=1 upon receipt of SRv message 22; the next hop of the IPv6 header 301 header is modified to SID 7:1, the SRv message 22 is modified to SRv6 message 23, and the message is sent to PE207.

Fig. 3 is a schematic diagram of a SRv message forwarding embodiment of the tail node protection provided by the present application. In the embodiment shown in FIGS. 2 and 3, PE207 is configured with mirror SID 7:1 and VPN SID 6:100 of PE206 requiring backup protection is a remote VPN (remote) SID, thereby providing a backup protection configuration.

PE207 is configured with hardware termination table entries for the mirror SID: 1 is a full F mask equal to the length of the mirror SID; the outlet port is an inner ring port.

PE207 is configured with a remote VPNSID hardware termination table entry: wherein the matching item is a remote VPN SID6 of 100 and a full F mask equal to the length of the remote VPNSID; the outlet port is an inner ring port subinterface which is bound with the inner ring port subinterface and is bound with VPN SID 6:100.

PE207 receives SRv message 23 and modifies sl=1 of SRH303 header to sl=0, as shown in SRv6 message 24; 1, searching a mirror SID hardware termination table item based on mirror SID7 of an SRH303 header of the SRv message 24; forwarding SRv the message 24 through the inner ring port.

PE207 receives SRv message 24 through inner ring port, determines SL=0 of SRH303 header, and strips off SRH header 303 as indicated by SRv message 25; 100, searching a remote VPNSID hardware termination table based on the remote VPN SID6 of the SRH303 head; forwarding SRv the message 25 through the inner ring subinterface.

PE207 receives SRv message 25 through inner ring port, determines SRH302 head SL=0, peels off SRH head 302, searches the destination IP address of inner layer IP message 300 in the route table of VPN bound by inner ring sub-interface, and sends inner layer IP message 300 to CE208 through the found out interface.

Fig. 4 is a schematic diagram of another embodiment of forwarding a SRv message with tail node protection according to the present application. In the embodiment shown in FIGS. 2 and 3, PE207 is configured with mirror SID 7:1 and public network SID 6:1 of PE206 requiring backup protection is a remote (remote) SID, thereby providing a backup protection configuration.

PE207 is configured with hardware termination table entries for the mirror SID: 1 is a full F mask equal to the length of the mirror SID; the outlet port is an inner ring port.

PE207 is configured with a remote SID hardware termination table entry: wherein the matching item is a remote SID6 of 100 and a conventional matching mask equal to the locator length; the outlet port is an inner ring port subinterface which is bound with the inner ring port subinterface and is bound with VPN SID 6:100.

In the embodiment of fig. 2 and 4, when the PE204 determines that the path to the PE206 is not reachable, it encapsulates with the mirror SID 7:1, adds the backup path SRH header 303, in the SRH header 303 of the SRv message 21, sl=2 and segments list are pushed in reverse order according to the backup path 6:1, 7:1, 5:1, modifies the next hop of the IPv6 header 301 header to SID 5:1, modifies the SRv6 message 21 to SRv6 message 22', and sends SRv message 22' to the PE205.

PE205 modifies sl=2 of the SRH303 header to sl=1 upon receipt of SRv6 message 22'; the next hop of the IPv6 header 301 header is modified to SID 7:1, the SRv message 22 is modified to SRv6 message 23' and sent to PE207.

PE207 receives SRv message 23', modifies sl=1 of SRH303 to sl=0, as shown in SRv message 24'; 1, searching a mirror SID hardware termination table item based on mirror SID7 of an SRH303 head of the SRv message 24'; forwarding SRv message 24' through the inner ring port.

PE207 receives SRv message 24' through inner ring port, determines SL=0 of SRH303, and peels off SRH header 303 as indicated by SRv message 25; 1, searching a remote SID hardware termination table based on the remote SID6 of the SRH303 head; forwarding SRv the message 25 through the inner ring subinterface.

PE207 receives SRv message 25 through inner ring port, determines SL=0 of SRH302, peels off SRH header 302, searches for destination IP address of inner layer IP message 300 in route table of VPN bound by inner ring sub-interface, and sends inner layer IP message 300 to CE208 through found out interface.

The application saves the loop back port resource in the equipment, and realizes secondary loop back by arranging loop back sub-interfaces; in the embodiments of fig. 2, 3, and 4, two different physical loopback interfaces may be provided as the egress port of the mirror SID hardware termination table entry and the egress port of the remote VPN SID hardware termination table entry/remote SID hardware termination table entry, respectively.

Fig. 5 is a schematic diagram of a message forwarding device provided in the present application, where the device 50 at least includes: network interface, exchange chip, CPU and memory. The memory is used for storing processor executable instructions; wherein the processor receives the message with SRv by executing processor-executable instructions in the memory to perform operations comprising; the outer layer destination IP address of SRv message is the mirror image SID of local configuration, SRv6 message has double-layer SRH head and SL of outer layer SRH head is equal to penultimate jump; SL for inner SRH equals last hop; terminating the mirror SID of the outer layer SRH header of SRv through the mirror termination table entry and looping back; terminating the virtual private network VPN SID of the protected tail node of the outer layer SRH header of the looped-back SRv message through the remote termination table entry, stripping the outer layer SRH header and looping back again; stripping the inner layer SRH head of the re-looped SRv message to obtain an inner layer IP message; identifying VPN examples which belong to the IP messages according to the inner layer; and searching an output port of a destination IP address of the inner layer IP message in the identified VPN example, and sending the IP address.

The matching item of the mirror image termination table item is a mirror image SID and a mask equal to the length of the mirror image SID; the exit port of the mirror termination table entry is the first loopback port.

The matching item of the remote termination table item is a virtual private network VPN SID configured at the local protected tail node and a mask equal to the VPN SID length; the exit port of the remote termination entry is the second loopback port.

The remote termination table entry matching item is a remote SID of a public network SID configured on a local protected tail node and a mask which is equal to the locator length of the public network SID; the exit port of the remote termination entry is the second loopback port.

The first loopback port and the second loopback port are different physical loopback ports; alternatively, the first loopback port is a physical loopback port and the second loopback port is a sub-interface of the first loopback port.

The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather to enable any modification, equivalent replacement, improvement or the like to be made within the spirit and principles of the application.

Claims (10)

1. A method for forwarding a message, the method comprising:

receiving a message with SRv; the outer layer destination IP address of the SRv message is a mirror image SID configured locally, the SRv message has a double-layer SRH header, and SL of the outer layer SRH header is equal to the penultimate hop; SL for inner SRH equals last hop;

terminating the mirror SID of the outer layer SRH header of the SRv by a mirror termination table entry and looping back;

terminating the virtual private network VPN SID of the protected tail node of the outer layer SRH header of the looped-back SRv message through a remote termination table entry, stripping the outer layer SRH header and looping back again;

stripping the inner layer SRH head of the re-looped SRv message to obtain an inner layer IP message;

identifying a VPN instance which belongs to the inner layer IP message;

and searching an output port of a destination IP address of the inner layer IP message in the identified VPN example, and sending the IP address.

2. The method of claim 1, wherein the step of determining the position of the substrate comprises,

the matching item of the mirror image termination table item is the mirror image SID and a mask which is equal to the length of the mirror image SID; the output port of the mirror termination table entry is a first loopback port.

3. The method of claim 1, wherein the matching entry of the remote termination entry is a virtual private network VPN SID of the protected tail node configured locally and a mask equal to the VPN SID length; and the output port of the remote termination table entry is a second loopback port.

4. The method of claim 1, wherein the remote termination entry matching entry is a remote SID of a public network SID of the protected tail node configured locally and a mask of locator length equal to the public network SID; and the output port of the remote termination table entry is a second loopback port.

5. The method according to claim 3 or 4, wherein,

the first loopback port and the second loopback port are different physical loopback ports; or alternatively, the process may be performed,

the first loopback port is a physical loopback port, and the second loopback port is a sub-interface of the first loopback port.

6. A message forwarding device, wherein the device comprises a processor and a memory; the memory is used for storing processor executable instructions; wherein the processor is configured to, by executing processor-executable instructions in the memory, perform the following:

receiving a message with SRv; the outer layer destination IP address of the SRv message is a mirror image SID configured locally, the SRv message has a double-layer SRH header, and SL of the outer layer SRH header is equal to the penultimate hop; SL for inner SRH equals last hop;

terminating the mirror SID of the outer layer SRH header of the SRv by a mirror termination table entry and looping back;

terminating the virtual private network VPN SID of the protected tail node of the outer layer SRH header of the looped-back SRv message through a remote termination table entry, stripping the outer layer SRH header and looping back again;

stripping the inner layer SRH head of the re-looped SRv message to obtain an inner layer IP message;

identifying a VPN instance which belongs to the inner layer IP message;

and searching an output port of a destination IP address of the inner layer IP message in the identified VPN example, and sending the IP address.

7. The apparatus of claim 6, wherein the matching entry of the mirror termination table entry is the mirror SID and a mask equal to the mirror SID length; the output port of the mirror termination table entry is a first loopback port.

8. The apparatus of claim 6, wherein the matching entry of the remote termination entry is a virtual private network VPN SID of the protected tail node configured locally and a mask equal to the VPN SID length; and the output port of the remote termination table entry is a second loopback port.

9. The apparatus of claim 6, wherein the remote termination entry matching entry is a remote SID of a public network SID of the protected tail node configured locally and a mask of locator length equal to the public network SID; and the output port of the remote termination table entry is a second loopback port.

10. The apparatus of claim 8 or 9, wherein the first loopback port and the second loopback port are different physical loopback ports; or alternatively, the process may be performed,

the first loopback port is a physical loopback port, and the second loopback port is a sub-interface of the first loopback port.