Internet Protocol version 4 (IPv4) is the core protocol of the TCP/IP protocol suite. All TCP, UDP, IGMP, and ICMP data is carried in IP packets. Devices on different networks use IP addresses for communication. In addition, to ensure the security of the TCP/IP protocol suite, you can defend against network attacks by controlling ICMP packets and IP packets carrying options.
A network ID uniquely identifies a network segment or a group of network segments. A network ID can be obtained by converting an IP address and subnet mask into binary numbers and performing an AND operation on the numbers.
A host ID uniquely identifies a device on a network segment. A host ID can be obtained by converting an IP address and subnet mask into binary numbers, reversing the post-conversion subnet mask, and performing an AND operation on the numbers.
If multiple devices on a network segment have the same network ID, they belong to the same network, regardless of their physical locations.