There are 2 main types of bans in CSGO:
VAC bans are permanent and always issued on the account level. Not on the IP.
When you join a community server, the admins of that server have full rights to ban you from their server for any reason (not just for cheating). Almost all community server bans are applied on the account level, too. Its extremely rare for people to be banned by IP but it's not impossible.
If you get banned on a community server, you will usually receive a message with a link where you can find more info about the ban. Sometimes you can even contact the owners.
Because its ineffective:
If you've received an IP ban on a community server, consider yourself lucky. You can change your IP and connect back to the server in minutes by simply resetting your modem. Find more ways to change your IP here.