This paper presented a study on the implementation of fault-tolerant network interfaces for NoCs. A fault-free network interface assumes a particular relevance in the design of a reliable multiprocessor system-on chip (MPSoC). In this paper, we focus on an NI providing basic communication services. Presented fault models and fault-tolerant techniques can be, however, extended to include additional services. In this work, we consider the NI as an independent hardware block located between the core and the communication infrastructure. Experimental simulations show that with a limited overhead, we can obtain an NI reliability comparable to the one obtainable by implementing the system by using standard triple modular redundancy techniques, while saving up to 48 percent in area, as well as obtaining a significant energy reduction.