I'm using a VPS for Monero mining, but the cloud does not have DDoS protection, so I'm making iptable rules. A friend who knows how to mess with Linux (Ubuntu 16) made a configuration that he thinks is the best he has ever tested. But the configuration does not allow any data traffic to enter. With this the cpumulti does not connect to the pool. Does anyone here know of a rule that I can put that releases cpumulti? I already tried the pool doors and it will not. I use the Wolf version ... Anyone?
The miners use standard HTTP, and the pool will send information to the miner via the connection the miner itself initiated. This means you don't need any incoming rules for new connections. You will need to allow new outgoing connections to the port you want to mine on (this depends on your pool and chosen starting difficulty, see the "Getting started" page on the pool for details), and allow incoming data on the same connection.
Now I can't give iptables rules for this, but since it's a bog standard TCP duplex connection, you should be able to easily find one on the internet and adjust the port number.