vermin can ,you can if you find the software,other than that if its just to block 1 ip its a waste you can use other software to bypass,so you can block ip in firewall but if someone wants to get back all they do is swap ip ,easy to do.
block what ? Inbound ? Outbound ? what are you trying to stop ? external IP shouldn't be able to access any internal services unless you have opened that port.
You would need an ACL (Access control list) but I dont think those are supported on the superhub. You could block them via a firewall of some description.