About Fabric Port Tracking
The port tracking feature manages the status of downlink ports on each leaf node based on the status of its fabric ports. Fabric ports are the links between leaf and spine nodes. Links between tier-1 and tier-2 leaf nodes in multi-tier topologies and links between remote leaf nodes (back-to-back links) are also considered to be fabric links.
When this feature is enabled and the number of operational fabric ports on a given leaf node is decreased to the configured threshold or lower, the downlink ports of the leaf node will be brought down so that external devices can switch over to other healthy leaf nodes. When the number of operational fabric ports comes back up to greater than the configured threshold, the downlink ports will be brought back up. At this time, there will be a wait time of the configured delay before the downlink ports are brought up. If the leaf node is part of a vPC peer and does not have any infra ISIS adjacencies--meaning that the node is unable to communicate with the other vPC peer leaf node--when port tracking is triggered such as when all fabric ports went down, the wait time for the vPC downlink ports to come up after the status restoration will be the longer time of either the vPC delay timer or the configured delay in port tracking. Non-vPC downlink ports always follow the delay timer configured in port tracking.
Note |
Port tracking checks the conditions to bring down the ports or bring up the ports every second on each leaf node. FEX fabric ports--that is, the network interface (NIF) to connect the FEX and the FEX's parent leaf node--are not impacted by port tracking. |