why is the gateway/router ip address is usually the first usable ip address in the network
Default gateway
A packet addressed outside of this range , for this example , addressed to 192.168. 12.3 , can not travel directly to the destination . Instead it must be sent to the default gateway for further routing to their ultimate destination . In this example , the default gateway uses the IP address 192.168. 4.1 , which is resolved into a MAC address with ARP in the usual way . The destination IP address remains 192.168. 12.3 , but the next - hop physical address is that of the gateway , rather than of the ultimate destination .
A packet addressed outside of this range , for this example , addressed to 192.168. 12.3 , can not travel directly to the destination . Instead it must be sent to the default gateway for further routing to their ultimate destination . In this example , the default gateway uses the IP address 192.168. 4.1 , which is resolved into a MAC address with ARP in the usual way . The destination IP address remains 192.168. 12.3 , but the next - hop physical address is that of the gateway , rather than of the ultimate destination .