A hardware system designed to support the peer-to-peer Ethernet is presented. Sampled datum transferring on process level in digital substation can be employed in either networking mode or peer-to-peer mode. In networking mode， a stable unified clock source for whole substation is necessary，and the substation always takes risks of clock source and the integrity of the network. When transferring IEC 61850-9-2 data frames in peer-to-peer mode， it will take the benefits of flexible configuration and high compatibility of IEC 61850-9-2， and provides much more reliability for the protection system with fixed data transferring delay. In 500 kV Lanxi substation upgrade project， the peer-to-peer IEC 61850-9-2 sampled value is applied.