The COVID-19 pandemic led to the adoption of severe measures to counteract the spread of the infection. Social distancing and lockdown measures modifies people's habits, while the Internet gains a major role to support remote working, e-teaching, online collaboration, gaming, video streaming, etc. All these sudden changes put unprecedented stress on the network. In this paper we analyze the impact of the lockdown enforcement on the Politecnico di Torino campus network. Right after the school shutdown on the 25th of February, PoliTO deployed its own in-house solution for virtual teaching. Ever since, the university provides about 600 virtual classes daily, serving more than 16,000 students per day. Here, we report a picture of how the pandemic changed PoliTO's network traffic. We first focus on the usage of remote working and collaborative platforms. Given the peculiarity of PoliTO in-house online teaching solution, we drill down on it, characterizing both the audience and the network footprint. Overall, we present a snapshot of the abrupt changes on campus traffic and learning due to COVID-19, and testify how the Internet has proved robust to successfully cope with challenges and maintain the university operations.