An NREN network is an aggregation of member institution networks. Sadly, the state of the member institution networks, and the technical competence of member institution network and systems administrators are, many a time, not considered vital contributors to the growth of an NREN. The member institution technical staff are faced with various hardships in their day to day tasks. Aside from the limited budgets allocated to ICT departments, there are two other major reasons for these hardships; the limited network and systems support skills, and the very poor state of the networks of member institutions - many of which are inherited from several generations of neglect. In this paper, we present the technical capacity building drive that was undertaken in RENU and also seek to bring out the impact it has had on the growth of RENU as an NREN. The background and the problems facing campus networks are brought out in the first chapter of this paper. The second chapter details the activities and structure of the RENU capacity building program. In the third chapter, we discuss the benefits and results (both direct and indirect) that have come out of the capacity building program. A trajectory of RENU’s growth from 2014 as a network and an NREN community is discussed, highlighting the invisible contribution of technical capacity building. The challenges faced are discussed in the chapter before the conclusion. We conclude by arguing that an NREN suffers in various ways when member institution networks function sub optimally. Keywords/phrases: throughput, bandwidth, latency, bottleneck, capacity building, campus networks, direct engineering assistance.