May 24, 2021 That's what Linux should learn
Dynamic Host Configuration Protocol (DHCP) is a network protocol based on UDP protocol and limited to use within the LOCAL Network, mainly used in large LAN environments or lanter environments with more mobile office equipment, the main purpose of which is to automatically assign IP addresses and other parameters for devices or network providers within the LAN.
Simply put, the DHCP protocol is a service that allows hosts in a local area network to automatically obtain network parameters. T here are multiple hosts in the topology diagram shown in Figure 14-1, and if you manually configure the network parameters for each host, it can be cumbersome to maintain later. A nd when the number of hosts in the room increases further (for example, 100 or even 1,000), this manual configuration and maintenance work is enough to crash the operations staff. With the DHCP protocol, not only can network parameters be automatically assigned to the host, but also the IP address used by the host is unique and, more importantly, a fixed IP address can be assigned to a particular host.
A topology diagram of the 14-1 DHCP protocol
DhCP protocol is widely used, whether it is server room or home, airport, coffee shop, will see it. F or example, one of the book's readers opened a coffee shop that provided customers with free Wi-Fi while providing coffee. T his way, customers can enjoy a cup of coffee while brushing their circle of friends on Wi-Fi. H owever, as the owner of the coffee shop, you certainly do not want (and do not have time) for each visiting customer to manually set IP address, subnet mask, gateway address and other information. I n addition, considering that the intranet segments used in coffee shops are generally 192.168.10.0/24 (class C private addresses), the maximum number of hosts can accommodate more than 200. A nd the coffee shop must have more than 200 visitors a day. I f they are manually assigned an IP address, it is not automatically released when they leave the coffee shop, which may result in insufficient IP address. T his aspect will cause the waste of IP address, on the other hand, also increase the management cost of IP address. With the DHCP protocol, all this is solved - the boss only needs peace of mind to serve customers, provide them with delicious coffee, customers through the server running the DHCP protocol automatically get the IP address required to access the Internet, and so on when leaving the coffee shop IP address will be retracted by the DHCP server for other customers to use.
Now that you're sure you can't live without DHCP in your future production environment, it's important to familiarize yourself with the common terms involved in DHCP.
Scope: A complete IP address segment, and the DHCP protocol manages the distribution of the network, assigns IP addresses, and other configuration parameters based on scope.
Super scope: Used to manage multiple logical subnet segments that are on the same physical network. Super scopes contain a list of scopes that can be managed uniformly.
Exclusion: Exclude some IP addresses in the scope to ensure that they are not assigned to DHCP clients.
Address pool: After defining the scope of the DHCP and applying the exclusion range, the remaining IP address range is dynamically assigned to the DHCP client.
Lease: The time when DHCP clients were able to use dynamically assigned IP addresses.
Appointment: Ensure that specific devices on the network always get the same IP address.