Packet transmission method, proxy node, and storage medium
This application discloses a packet transmission method, a proxy node, and a storage medium, and pertains to the field of communications technologies. According to the method, a new SID with a bypass function is extended for an End.AD SID. Therefore, when receiving a packet that carries the End.AD SID, a local proxy node uses this new SID to transmit an SRH of the packet to a peer proxy node in a bypass manner, so that the peer proxy node can also obtain the SRH of the packet, and therefore the SRH of the packet can be stored in the peer proxy node. In this way, synchronization of the SRH of the packet can be implemented between the two proxy nodes that are dual-homed to a same SF node, so that the SRH of the packet is redundantly backed up.
1. A packet transmission method, applied in a first proxy node, wherein the method comprises:
receiving a first packet, wherein the first packet comprises a segment routing header (SRH), and a destination address of the first packet is an endpoint dynamic proxy segment identifier (SID);
generating a second packet based on the endpoint dynamic proxy SID, the first packet, and a first bypass SID corresponding to a second proxy node, wherein the second packet comprises the first bypass SID, control information, and the SRH of the first packet, the first bypass SID is used to identify that a destination node of the second packet is the second proxy node, the control information is used to indicate the second proxy node to store the SRH of the first packet, and the second proxy node and the first proxy node are connected to a same service function node; and
sending the second packet to the second proxy node.
2. The method according to claim 1 , wherein the generating a second packet based on the endpoint dynamic proxy SID, the first packet, and a first bypass SID corresponding to a second proxy node comprises:
inserting the first bypass SID into a segment list of the SRH of the first packet;
updating a segment left (SL) of the SRH of the first packet; and
updating the destination address of the first packet to obtain the second packet, wherein an SL of the second packet is greater than an SL of the first packet.
3. The method according to claim 2 , wherein the updating a segment left (SL) of the SRH of the first packet comprises:
increasing the SL of the first packet by one; and
the updating the destination address of the first packet comprises:
updating the destination address of the first packet to the first bypass SID.
4. The method according to claim 2 , wherein the method further comprises:
inserting one or more target SIDs into the segment list of the SRH of the first packet, wherein the one or more target SIDs are used to indicate a target forwarding path, and the target forwarding path is a path from the first proxy node to the second proxy node;
the updating a segment left (SL) of the SRH of the first packet comprises:
increasing the SL of the first packet by N, wherein N is a positive integer greater than 1; and
the updating the destination address of the first packet comprises:
updating the destination address of the first packet to a SID corresponding to a next segment routing SR node in the one or more target SIDs.
5. The method according to claim 1 , wherein
the control information is carried in an extension header of the second packet;
the control information is carried in the first bypass SID;
the control information is carried in an internet protocol (IP) header of the second packet; or
the control information is carried in a type length value (TLV) in an SRH of the second packet.
6. The method according to claim 1 , wherein after the receiving a first packet, the method further comprises:
storing the SRH of the first packet in a first cache entry;
generating a third packet based on the first packet, wherein the third packet comprises a payload of the first packet but does not comprise the SRH of the first packet; and
sending the third packet to the service function node.
7. The method according to claim 6 , wherein the storing the SRH of the first packet in a first cache entry comprises:
storing the SRH of the first packet in the first cache entry using an identifier of the first cache entry as an index.
8. The method according to claim 7 , wherein the second packet further comprises the identifier of the first cache entry, the control information is further used to indicate to the second proxy node to store a mapping relationship between the identifier of the first cache entry and an identifier of a second cache entry, and the second cache entry is a cache entry used by the second proxy node to store the SRH of the first packet.
9. The method according to claim 6 , wherein the third packet comprises an identifier of the first cache entry; and after the sending the third packet to the service function node, the method further comprises:
receiving a fourth packet from the service function node, wherein the fourth packet comprises an identifier of the first cache entry;
performing query by using the identifier of the first cache entry as an index, to obtain the SRH of the first packet;
generating a fifth packet based on the fourth packet and the SRH of the first packet, wherein the fifth packet comprises a payload of the fourth packet and the SRH of the first packet; and
sending the fifth packet.
10. A first proxy node, wherein the first proxy node comprises:
a memory storing instructions; and
a processor coupled to the memory, wherein execution of the instructions causes the first proxy node to:
receive a first packet, wherein the first packet comprises a segment routing header (SRH), and a destination address of the first packet is an endpoint dynamic proxy segment identifier (SID);
generate a second packet based on the endpoint dynamic proxy SID, the first packet, and a first bypass SID corresponding to a second proxy node, wherein the second packet comprises the first bypass SID, control information, and the SRH of the first packet, the first bypass SID is used to identify that a destination node of the second packet is the second proxy node, the control information is used to indicate the second proxy node to store the SRH of the first packet, and the second proxy node and the first proxy node are connected to a same service function node; and
send the second packet to the second proxy node.
11. The first proxy node according to claim 10 , wherein execution of the instructions further causes the first proxy node to:
insert the first bypass SID into a segment list of the SRH of the first packet; update a segment left (SL) of the SRH of the first packet; and update the destination address of the first packet to obtain the second packet, wherein an SL of the second packet is greater than an SL of the first packet.
12. The first proxy node according to claim 11 , wherein execution of the instructions further causes the first proxy node to: increase the SL of the first packet by one;
and update the destination address of the first packet to the first bypass SID.
13. The first proxy node according to claim 11 , wherein execution of the instructions further causes the first proxy node to: insert one or more target SIDs into the segment list of the SRH of the first packet, wherein the one or more target SIDs are used to indicate a target forwarding path, the target forwarding path is a path from the first proxy node to the second proxy node; increase the SL of the first packet by N, wherein N is a positive integer greater than 1; and update the destination address of the first packet to a SID corresponding to a next segment routing SR node in the one or more target SIDs.
14. The first proxy node according to claim 10 , wherein
the control information is carried in an extension header of the second packet;
the control information is carried in the first bypass SID;
the control information is carried in an internet protocol (IP) header of the second packet; or
the control information is carried in a type length value (TLV) in an SRH of the second packet.
15. The first proxy node according to claim 10 , wherein execution of the instructions further causes the first proxy node to:
store the SRH of the first packet in a first cache entry,
generate a third packet based on the first packet, wherein the third packet comprises a payload of the first packet but does not comprise the SRH of the first packet; and
send the third packet to the service function node.
16. The first proxy node according to claim 15 , wherein execution of the instructions further causes the first proxy node to store the SRH of the first packet in the first cache entry using an identifier of the first cache entry as an index.
17. The first proxy node according to claim 16 , wherein the second packet further comprises the identifier of the first cache entry, the control information is further used to indicate to the second proxy node to store a mapping relationship between the identifier of the first cache entry and an identifier of a second cache entry, and the second cache entry is a cache entry used by the second proxy node to store the SRH of the first packet.
18. The first proxy node according to claim 15 , wherein execution of the instructions further causes the first proxy node to:
receive a fourth packet from the service function node, wherein the fourth packet comprises an identifier of the first cache entry; and
perform a query using the identifier of the first cache entry as an index, to obtain the SRH of the first packet,
generate a fifth packet based on the fourth packet and the SRH of the first packet, wherein the fifth packet comprises a payload of the fourth packet and the SRH of the first packet; and
send the fifth packet.