Investigating the prefix-level characteristics: A case study in an IPv6 network

As IPv6 has much larger address space than IPv4, understanding the characteristics of IPv6 prefixes is of great benefit to guide the efficient IPv6 routing cache design. In this paper, we make a first-ever analysis of prefix-level characteristics in IPv6 world. We first investigate the assignment and activity of IPv6 prefixes. Then we characterize the traffic and packet distribution across prefixes based on the traces of an IPv6 network. At last, we analyze the size of the active prefixes across different time scales and capture the number of emerging and vanishing prefixes. Our results show that the number of assigned prefixes and the coverage areas are increasing and expanding. Traffic and packet distribution across prefixes are highly skewed. The sizes of active prefixes are relatively stable over time. If we update the routing cache once an hour, we only need to reserve 5184 bytes memory for the worst-case burst changes.