We block the following ports on our whole network both for incoming and outgoing connections, these are commonly used for malicious activity such as DDoS attacks.
- TCP & UDP port 17
- TCP & UDP port 19
- TCP & UDP port 111
- TCP & UDP port 1900
- UDP port 11211
- UDP port 53413
These blocks are permanent, and cannot be removed.
PS: For All China hosting, port 80 is blocked by default.