Volunteer cloud is a new concept of cloud computing where volunteers, i.e., user machines are used instead of or in addition to dedicated resources. Although volunteer clouds offer potential benefits in terms of energy and cost saving as well as elasticity, the volatility and the scalability of the volunteer resources are still open challenges that need to be investigated. In this paper, we focus on managing the connectivity in a scalable and dynamic fashion in volunteer clouds. We show that volunteer clouds could be modelled by a hierarchical small-world structure, characterised by short average path lengths among nodes, and strong local clustering, which implies small latency between nodes and therefore robust forwarding. Furthermore, we explore the benefits of the use of the recursive internetwork architecture (RINA) as a networking solution. Finally, simulation results show that our proposal achieves a trade-off between bounding the routing table size and ensuring transmission efficiency