Official transmigration programs have moved millions of people from the cores of domestic economies to national geographical peripheries with a goal to facilitate more equitable distribution of resources. Despite the size of these programs there is limited evidence of how transmigrants impact and fit in local communities in remote farming regions to which they move and how this impacts farming communities social structure. This paper draws on the experience of Javanese transmigrants in Indonesia as the major transmigration group and examines how ethnic affiliation and transmigratory experience shapes social networks of 315 smallholder farmers in 16 communities in Lampung province, Sumatra. We analyse how ethnicity and migration experience relate the network centrality and network "coreness" of farmers in these communities. Network analysis and regression analysis showed that descendants of Javanese migrants tend to form the social core of the local communities in terms of their structural position in farmers' knowledge networks, apparently benefiting both from strong cultural links to the central regions of the country in Java as well as strong embeddedness in local communities. These findings have implications for knowledge-sharing peripheral communities and resilience of local farming systems in the face of environmental change.