The eBlocker can only work within one of the three so-called private IP address ranges. These three IP address ranges are intended for private use in local networks.
The three IP address ranges are:
10.0.0.0 to 10.255.255.255
172.16.0.0 to 172.31.255.255
192.168.0.0 to 192.168.255.255
(Source Wikipedia: https://en.wikipedia.org/wiki/Private_network)
This means that the eBlocker can operate for example in the IP address range from 192.168.1.1 to 192.168.1.254, but not in a network that either hosts several IP address ranges, or whose IP address range is outside one of the three IP address ranges listed above.