摘要 |
A technique distinguishes between link and node failure using bidirectional forwarding detection (BFD) in a computer network. According to the novel technique, a BFD session is established over a first link between a monitoring node and a first interface of a monitored node. In addition, one or more novel unidirectional BFD (uBFD) sessions from one or more corresponding other interfaces of the monitored node to the monitoring node (e.g., as configured by the monitored node to detect its failure), the one or more uBFD sessions traversing links other than the first link (e.g., "not-via" the monitored node) are established, the one or more uBFD sessions traversing links other than the first link (e.g., "not-via" the monitored node). For instance, the one or more uBFD sessions correspond to one or more line cards of the monitored node. In response to detecting a lack of connectivity resulting from, e.g., failure of the BFD session, the monitoring node determines that the first link has failed if at least one uBFD session is operational. Moreover, in response to detecting failure of the BFD session and all of the one or more uBFD sessions, the monitoring node determines that the monitored node has failed.
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