Comment by walrus01

Netblocks has been doing some very good work tracking the presence or absence of known IP blocks previously announced by Iranian ASNs. The charts really speak for themselves.

For those who don't keep track of backbone ISP topologies: Iran has 3 or 4 major entirely government controlled ASNs which all domestic ISPs are obligated to be downstream of.

The government controlled AS run all the international transit connections (at the BGP level) and also the physical fiber/longhaul DWDM systems into a few neighboring countries. It makes it very easy to cut off all the downstream domestic only ISPs.

https://netblocks.org/