In this paper, we study the performance metrics of a two-stage switch of an all-optical network in the event of faults and traffic surges. For the analysis, we use a model of a two-phase queuing system with a common buffer, which adequately describes the operation of an all-optical two-stage switch. Analytical expressions are obtained for finding the probabilities of system states, throughput, and the buffer size of the first and second stages in the case of a step-wise change in the arrival and service rates using the resulting probability translation matrix. The results of numerical experiments allowed us to draw a conclusion about the nature of the change in the performance metrics of the switch in the event of faults in the switching elements of individual stages, as well as in the event of traffic surges.