arXiv:2610.29787v1 Announce Type: new Abstract: Pingmesh monitors datacenter networks through periodic pings between servers. In reconfigurable datacenter networks, topology engineering (TPE) and traffic engineering (TE) make uniform server-pair probing inefficient: a pinglist wastes budget retesting common paths while missing low-probability interfaces. Frequent control-plane updates further require rapid pinglist refresh, and cause path ambiguity at control-plane boundaries for fault localization. We present D-Pingmesh, a probing and fault-localization system co-designed with the TPE/TE control plane. Its control-plane-aware generator builds task-efficient pinglists by greedily admitting probes with high interface coverage under the current TPE/TE snapshot. An incremental replay-and-repair mechanism updates pinglists across reconfigurations rather than recomputing from scratch. At control-plane boundaries, a Rho-EM localizer jointly infers per-task old/new-path mixture weights and the fault set through EM-style iteration. We evaluate D-Pingmesh on an 8-pod reconfigurable topology under dynamic TPE/TE. At a 0.99 coverage target, D-Pingmesh uses 17.7x fewer tasks than Pingmesh and generates each pinglist about 5.1x faster than RD-Probe. In ns-3 simulation, boundary-aware localization improves micro F1 from 0.871 to 0.953 over the deTector PLL baseline. A testbed deployment demonstrates second-scale fault localization with low host overhead. These results demonstrate that D-Pingmesh is practical for reconfigurable datacenter networks with control-plane-aware monitoring.