Method and apparatus for transmitting BFD (bidirectional forwarding detection) message during LSP (label switched path) detection by BFD

Abstract

The invention discloses a method and an apparatus for transmitting a BFD message during LSP detection by BFD. The method comprises: an Ingress node setting a destination IP (internet protocol) to the local IP address in a BFD message, adding a tag to the BFD message, and transmitting the BFD message with the tag to an Egress node; the Egress node removing the tag after receiving the BFD message with the tag, and forwarding the BFD message to the Ingress node by using the destination address of the BFD message; and the Ingress node receiving the BFD message to detect the connectivity of the LSP. In the invention, the Egress node only needs to forward the BFD message without creating a BFD session, thereby effectively improving the utilization rate of the BFD session.

Description

technical field [0001] The present invention relates to the field of communication technologies, and in particular, to a method and device for transmitting BFD packets when detecting LSPs through BFD. Background technique [0002] When using BFD (Bidirectional Forwarding Detection, bidirectional forwarding detection) to detect the connectivity of LSP (Label Switched Path, label switched path), it is necessary to establish a BFD session between the ingress (ingress) node and the egress (egress) node of the LSP , in order to use BFD to quickly detect the connectivity of the LSP; specifically, when detecting the connectivity of the LSP, the Ingress node needs to send a BFD control packet, that is, forward the BFD control packet along the LSP, and according to whether it is received or not, the BFD control packet is forwarded. The BFD control packets of the egress node are used to determine the connectivity of the LSP; and when the BFD detects the failure of the LSP, it can also...

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Problems solved by technology

[0008] However, when the Ingress node needs to perform BFD detection on a large number of LSPs between itself and the Egress node, the Egress node needs to establish a large number of BFD sessions, and the source IP addresses of these BFD sessions are all the IP addresses of the Egress node, and the destination IP addresses are all Ingress nodes. The IP address of the node, and the egress node will send BFD control packets to the ingress node according to the same destination IP address, and these BFD control packets may take the same forwarding path to the ingress node, thus causing the BFD session to be broken on the egress node A lot of waste, and reduce the BFD session utilization of egress nodes

[0009] Furthermore, when the Ingress node has a primary LSP and a backup LSP, the Egress node will establish a BFD session for the primary LSP and a BFD session for the backup LSP, and the source IP and destination IP of the two BFD sessions are the same; The BFD control packet sent by the node will reach the Ingress node through the same forwarding path. Once the forwarding path fails, BFD will cause both the active LSP and the standby LSP to report a DOWN event, which will cause the LSP active-standby switchover function to fail.

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