Is it possible to restrict Bitcoin's network traffic? Bitcoin is just a software running on a computer communicating securely with peers on the internet.
What will it take purely in technical terms to ban Bitcoin nodes from communicating with the network?

Assuming a node is starting for the first time, I believe it uses DNS seeds to find peers. If those DNS seeds are blocked, is it possible to prevent bitcoin node discovery ?
Is it possible to block certain ports to avoid bitcoin communication ?
Any other ways ISPs can detect bitcoin traffic ?
Banning peer to peer networks is very difficult in general.


Assuming a node is starting for the first time, I believe it uses DNS seeds to find peers. If those DNS seeds are blocked, is it possible to prevent bitcoin node discovery ?


This is possible but all you need in order to bypass it is one IP address of one peer and then you can connect to it manually and join the network


Is it possible to block certain ports to avoid bitcoin communication ?


Again that's possible but easily circumvented by changing the default ports


Any other ways ISPs can detect bitcoin traffic ?


Peer traffic is not encrypted so ISPs can flag bitcoin traffic by performing some inspection on the data being sent. But again this is bypassed by using a VPN or TOR.
Another way someone might try to stop you is blocking your internet access completely but this can be circumvented too because bitcoin is accessible via satellite, all you need is a dish and you don't rely on your ISP any more.