It is possible to Block by “Host Info”

No. It makes no sense in terms of security since the hostname can be easily spoofed.

Thank fro answer. But I kindle disagree, sometimes this solution makes more sense then IP. Someone can fast make Cloud VPS, with various IP, but host info will always the same like vps324444.cloudovh.com.
If I could block *.cloudovh.com, it would be more useful than an IP.

The host name of a web server can be set to virtually any value. The name vps324444.cloudovh.com is the default name set when someone bought the hosting. It’s changeable and so anyone can bypass your host-name-based block list.

Yes, of course, but I think it could be useful.
This would provide additional filtering options.
For example:

Sometimes spammers use cloud free plans. On many cloud services, and in most cases,free plan does not allow you to change the server name.

Local internet provider have wide IP pool allocated dynamicly, but only one host name.

If it was possible to add it to the list of suspicious (host and IP address, a gray list made by user) that would be handy, to track.

I agree the feature can be useful for some users in some circumstances. At the same time, a user must clearly understand that it’s a weak security feature with limitations. I think we will implement it as an add-on you need to install manually. The main disadvantages are:

1) Hostnames can be spoofed.
2) Determining the hostname from an IP address is time and resource consuming operation.

An additional plugin extending the manual IP Control capabilities would be very useful.
because I just have a problem with editing the Blacklist, but I will write that in another thread to keep things tidy.

Thank you very much for your valuable answers and your time.