Hi,
you can enable error interrupt in the enet component. Then when error is detected a configured callback is called with ENET_ERR_EVENT event. You can read interrupt flags using ENET_DRV_GetInterruptFlags to see what kind of errors was detected.
Also Enet module includes statistic and error counters so it can be used to monitor for frame traffic and errors. Counters are enabled by ENET_DRV_ConfigCounters and individual counters can be read using ENET_DRV_GetCounter. Or you can check those counters in debugger.
BR, Petr