IP address multiplexing for VEEs

Abstract

The number of publicly accessible virtual execution environments (VEEs) has been growing steadily in the past few years. To be accessible by clients, such VEEs need either a public IPv4 or a public IPv6 address. However, the pool of available public IPv4 addresses is nearly depleted and the low rate of adoption of IPv6 precludes its use. Therefore, what is needed is a way to share precious IPv4 public addresses among a large pool of VEEs. Our insight is that if an IP address is assigned at the time of a client DNS request for the VEE's name, it is possible to share a single public IP address amongst a set of VEEs whose workloads are not network intensive, such as those hosting personal servers or performing data analytics. We investigate several approaches to multiplexing a pool of global IP addresses among a large number of VEEs, and design a system that overcomes the limitations of current approaches. We perform a qualitative and quantitative comparison of these solutions. We find that upon receiving a DNS request from a client, our solution has a latency as low as 1 ms to allocate a public IP address to a VEE, while keeping the size of the required IP address pool close to the minimum possible.