What information can a DHCP server provide
The information that a DHCP server can provide is:
IP address
Subnet mask
Domain name
Default gateway
DNS
WINS information
What is dhcp service and what is its main function?
Dynamic Host Configuration Protocol, or DHCP for short, is a network protocol for local area networks that allows servers to dynamically assign IP addresses and configuration information to clients. Working with the UDP protocol, it has two main uses: to automatically assign IP addresses to an internal network or network service provider, and to users or internal network administrators as a means of centralized management of all computers.
DHCP has the following functions:
1. Guarantee that any IP address can only be used by one DHCP client at any one time;
2. DHCP should be able to assign permanent fixed IP addresses to users;
3. DHCP should be able to coexist with hosts that obtain IP addresses by other means (e.g., by using the UDP protocol). IP addresses (e.g., hosts with manually configured IP addresses);
4. The DHCP server should provide services to existing BOOTP clients.
What is DHCP in a network? What does it do? How to configure and set?
DHCP stands for Dynamic Host Configuration Protocol, and is one of the TCP/IP protocols used to assign dynamic IP addresses to network clients. These assigned IP addresses are pre-reserved by the DHCP server as a set of multiple addresses, and they are generally a contiguous segment of addresses.x0ax0a Understanding the DHCP Servicex0ax0a To use DHCP there must be a DHCP server on the network, while other machines perform DHCP client. When the DHCP client program sends a message requesting a dynamic IP address, the DHCP server provides a usable IP address and subnet mask to the client based on the currently configured address.x0ax0a1.Advantages of using DHCPx0ax0aDHCP enables a server to dynamically provide IP addresses to other servers in the network.x0ax0a By using DHCP, it is possible to not set and maintain static IP addresses for any servers in the Intranet network other than DHCP, DNS, and WINS servers. The use of DHCP greatly simplifies the task of configuring clients for TCP/IP, especially when certain TCP/IP parameters change, such as IP addresses and subnet masks due to large-scale reconstruction of the network.x0ax0aDHCP servers are computers running Microsoft TCP/IP, DHCP server software, and WindowsNTServer. computers, and DHCP clients are TCP/IP hosts that request TCP/IP configuration information.x0ax0aDHCP uses a client/server model, where a network administrator can create one or more DHCP servers that maintain TCP/IP configuration information and make it available to clients.x0ax0aThe IP address database on a DHCP server contains the following items: ● Valid configuration parameters for all clients on the Internet.x0ax0a ● Valid IP addresses assigned to clients in a buffer pool, as well as manually assigned reserved addresses.x0ax0a ● The server provides lease time, which is the amount of time that the specified IP address is available for use.x0ax0a Configuring a DHCP server in a network has the following advantages:x0ax0a ● Administrators can centrally specify generic and subnet-specific TCP/IP parameters for the entire Internet and can define parameters for clients using reserved addresses.x0ax0a ● Provides secure and trusted configurations.x0ax0a ● DHCP avoids configuration errors caused by manually typing in values on each computer, and it also prevents conflicting addresses from being configured on computers on the network.x0ax0a ● Using a DHCP server greatly reduces the overhead spent on configuration and the time it takes to reconfigure computers on the network. the server can configure all additional configuration values when assigning address leases.x0ax0a ● Clients do not need to be manually configured for TCP/IP.x0ax0a ● When a client moves between subnets, the old IP address is automatically released for reuse.x0ax0a ● Clients are not required to be manually configured with DHCP. The DHCP server automatically reconfigures TCP/IP for the client when the client is started up again.x0ax0a ● Most routers can forward DHCP configuration requests, so a DHCP server is not required for every subnet on the Internet.x0ax0a Note: x0ax0a If a DHCP server is to be used to support subnets that span multiple routers, the routers may require a hardware upgrade. The router must support RFCs 1533, 1534, 1541, and 1542.x0ax0a2.How DHCP Assigns Addressesx0ax0aDHCP uses a client/server model in which the network administrator establishes one or more DHCP servers in which TCP/IP configuration information that can be made available to the clients is stored. This information includes valid configuration parameters for the network clients, a pool of valid IP addresses assigned to the clients (which includes addresses reserved for manual configuration), and the duration of the leases offered by the servers.x0ax0a If computers on a TCP/IP network are set up to obtain IP addresses from DHCP servers, these computers become DHCP clients. When a DHCP client is started, it communicates with the DHCP server to receive the necessary TCP/IP configuration information. This configuration information contains, at a minimum, an IP address and subnet mask, as well as the leases associated with the configuration.x0ax0a There are three ways in which the DHCP server can assign TCP/IP addresses to DHCP clients:x0ax0a ● Manual Assignment: in Manual Assignment, the network administrator configures the IP address of the DHCP client by manual methods at the DHCP server. The DHCP server passes the manually configured IP address to the DHCP client when the DHCP client requests network services.x0ax0a ● Automatic Assignment: in automatic assignment, there is no need to perform any manual assignment of IP addresses. When a DHCP client leases an IP address from a DHCP server for the first time, this address is permanently assigned to that DHCP client and is not reassigned to any other client.x0ax0a ● Dynamic Assignment: when a DHCP client leases an IP address from a DHCP server, the DHCP server only temporarily assigns an IP address to the client. As soon as the lease expires, this address is returned to the DHCP server for use by other clients. If the DHCP client still needs an IP address to do its job, it can request another IP address.x0ax0a The dynamic assignment method is the only method that automatically reuses IP addresses, and it is especially convenient for DHCP clients that are temporarily connected to the network, and it is also a good way to assign IP addresses to new hosts that are permanently connected to the network.DHCP clients give up IP addresses when they are no longer needed, such as when a DHCP client is about to shut down normally, it can release the IP address to the DHCP server, which can then assign that IP address to the DHCP client that requested the IP address.x0ax0a The use of the dynamic allocation method can solve the problem of not having enough IP addresses, for example, a Class C network can only support 254 hosts, and there are more than 300 hosts on the network, but if there are up to 200 users on the network at the same time, at this time, if you use manual allocation or automatic allocation will not be able to solve this problem. Dynamic allocation of IP addresses is not fixed to a client, as long as there is a free IP address, the DHCP server can assign it to the client requesting the address; when the client no longer needs the IP address, it will be reclaimed by the DHCP server.