Why do we need private addresses such as RFC1918?
Well, say for instance you configure your local network with your router interface 126.96.36.199/24. You configure your clients with DHCP of range 188.8.131.52-184.108.40.206.
Everything will work fine, your clients in your local network will be able to contact each other. You can even S-NAT these addresses to your WAN-...
RFC 1918 provides address ranges that you can safely use within a private network without any danger that these same addresses might be used on the public Internet.
Any node within your network needs to be able to address any destination it requires. If your local network uses the same address range (subnet) that some public servers do (e.g 244.18.42.0/24), ...
(Host 1 is the one that needs to be fixed. Everyone else is /24)
Host 1 will send a layer-2 broadcast (ff:ff:ff:ff:ff:ff) as 0.15 is not a unicast host. (it won't ARP for it) Host 2 may answer, or it may drop the broadcast ICMP echo request. In either case, host 2 will see it.