I heard a rumor that Russia cannot disconnect Ukraine's internet infrastructure, because it is somehow interconnected with Poland, which is a NATO member. Disrupting Poland's internet could be seen as an act of agression against a NATO ally and would require NATO to respond.
Again, this is only a rumor that I have heard, don't have any sources to back it up. Maybe someone here knows more?
One of my 2 routers in Kyiv is on AS16007 'UKRAINIAN-AMERICAN-SWISS LIMITED LIABILITY PARTNERSHIP "KANCOM"'
Tracerouting to it from London shows traffic going from London onto AS8359 MTS (Russian ISP), seemingly to Frankfurt then Moscow, then to AS21497 PrJSC VF UKRAINE
The other router is on AS1820 WNET. Traceroute dies at London going to Ukraine, coming back the other way the ISP uses 100.64 ranges, so no idea where it routes. RTT via Russia is 70ms and via unknown is 40ms so I suspect it's direct.
Clearly Moscow could stop advertising Ukraine traffic out to the west, but then I guess traffic would be harder to intercept.
I do remember yesterday or the day before, NATO confirmed that cyberattacks fall into the category of attacks that require an Article 5 response. That is, Russia taking out Poland's internet would be considered an attack on NATO.
If Poland and Ukraine have intertwined backbones, that may have been the reason NATO felt compelled to make the announcement.
On the other hand, there were reports that the Russian navy has damaged parts of the internet cable between Norway and the Arctic. Norway is a NATO member, too. https://news.ycombinator.com/item?id=29903777
