The ukrainian internet under attack: an NDT perspective.

On February 24, 2022, Russia began a large-scale invasion of Ukraine, the first widespread conflict in a country with high levels of network penetration. Because the Internet was designed with resilience under warfare in mind, the war in Ukraine offers the networking community a unique opportunity to evaluate whether and to what extent this design goal has been realized. We provide an early glimpse at Ukrainian network resilience over 54 days of war using data from Measurement Lab's Network Diagnostic Tool (NDT). We find that NDT users' network performance did indeed degrade - e.g. with average packet loss rates increasing by as much as 500% relative to pre-wartime baselines in some regions - and that the intensity of the degradation correlated with the presence of Russian troops in the region. Performance degradation also correlated with changes in traceroute paths; we observed an increase in path diversity and significant changes to routing decisions at Ukrainian border Autonomous Systems (ASes) post-invasion. Overall, the use of diverse and changing paths speaks to the resilience of the Internet's underlying routing algorithms, while the correlated degradation in performance highlights a need for continued efforts to ensure usability and stability during war.