Modern applications necessitate geographically-distributed fragments over several data centers (DCs). Typical examples include stream or batch processing of geo-distributed data, or the redirection of clients to the optimal data replica. While little is known on inter-DC networks, the common belief is that they are not as well provisioned as intra-DC networks. They could thus be the bottleneck of multi-DC applications. As Amazon Web Services (AWS) is arguably the most popular Infrastructure-as-a-Service (IaaS) cloud provider, our focus is on the WAN connectivity offered by AWS in-between its DCs. We present preliminary results of a measurement campaign of the AWS WAN infrastructure, relying on traceroute measurements. Our initial observations highlight the complexity of the AWS infrastructure, which makes use of a variety of network solutions, including MPLS and Carrier-Grade NAT (CGNAT)