Data from the Internet Outage Detection and Analysis tool (IODA) shows a decline in the reachability of Ukrainian Internet address space since the beginning of the recent conflict with Russia. Over 15% of previously reachable Internet addresses are no longer responsive to probes from IODA.
The regions most impacted are unsurprisingly those where we know fighting has been most intense, e.g. Kherson, Donetsk, Luhansk, Kharkiv. The graph below illustrates all 27 regions of Ukraine ordered from most impacted to least. Chernihiv at the top of the graph had 270 blocks of 256 Internet addresses reachable before the invasion and now has 109, a decline of nearly 60%.
Commentary about the Ukrainian Internet since the start of the conflict with Russia has rightly observed that the diversity of infrastructure in the country is contributing to its resilience. Nevertheless we do observe that mass movement of people, interruption to power supplies and destruction of physical infrastructure are having an observable detrimental impact on the Internet in Ukraine.