Page 123 explains that we shouldn't have anything outside of the Apex subnet on the network and instructs the user to list the ARP table to confirm that. The manual assumes a /24 block but that's fine
The main problem is that it points at the multicast range and broadcast address as an example of problematic addresses. These should be ignored and are usually hardcoded in the TCP stack for the operating system. It's likely that everyone will have these for IPv4.