The owner of the ifn server turned out to be a putin supporter and he shut down the server as a protest. The IFN discord is still up though, you can read the err, "insightful" things he had to say there if you want to

Some of the members made their own server which is basically a copy of the IFN one with almost identical rules and blocklimits/hangars etc. Here's an invite to that server: discord.gg/vMaVvPEYA7 (IP address etc. is in the discord there). I haven't played on it myself yet but a good 50% of the people from the last server seem to be there.