Can the DHCP reserved address be provided for clients on S series switches

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For S series switches excluding the S1700:
Run the excluded-ip-address start-ip-address [ end-ip-address ] command in the IP address pool view or run the dhcp server excluded-ip-address start-ip-address [ end-ip-address ] command in the interface view to configure reserved addresses, which can be used as static addresses for clients.

Other related questions:
Can addresses that cannot be allocated dynamically be used by clients
Run the excluded-ip-address start-ip-address [ end-ip-address ] or dhcp server excluded-ip-address start-ip-address [ end-ip-address ] command to configure the IP addresses that cannot be automatically allocated in the DHCP address pool. The IP addresses are used as reserved addresses and can be used when clients use static addresses.

DHCP excluded addresses on S series switch
On an S series switch except an S1700 switch, you can use either of the following methods to configure the range of IP addresses that cannot be assigned to DHCP clients from the IP address pool: - Run the excluded-ip-address start-ip-address [ end-ip-address ] command in the IP address pool view. - Run the dhcp server excluded-ip-address start-ip-address [ end-ip-address ] command in the interface view. The excluded IP addresses are reserved as static IP addresses of DHCP clients.

Can clients connected to S series switch obtain IP addresses through DHCP
DHCP-enabled terminals that are connected to S series switches except S1700 switches can obtain IP addresses from DHCP servers when either of the following conditions is met: - The DHCP server function has been enabled on the switches. (By default, the DHCP server function is disabled on a switch.) - A DHCP server is available on the network and reachable to the terminals.

How to configure reserved IP addresses on S series switches
For S series switches excluding the S1700, some IP addresses of the network segment of an IP address pool may be occupied by servers or other hosts during network planning. Some clients have special requirements and can only be configured with some IP addresses; or to reserve some IP addresses that are not assigned dynamically. In this scenario, exclude these IP addresses in the IP address pool to prevent IP address conflicts caused by dynamically allocation of a DHCP server. Assume that IP addresses from 10.10.10.11 to 10.10.10.20 cannot be dynamically allocated. The configuration on S series switches excluding the S1700 is as follows: - Interface-based [HUAWEI] dhcp enable [HUAWEI] interface vlanif 100 //Enter the view of the interface connected to the DHCP client. [HUAWEI-Vlanif100] ip address 10.10.10.10 24 [HUAWEI-Vlanif100] dhcp select interface [HUAWEI-Vlanif100] dhcp server excluded-ip-address 10.10.10.11 10.10.10.20 - Global [HUAWEI] dhcp enable [HUAWEI] interface vlanif 100 //Enter the view of the interface connected to the DHCP client. [HUAWEI-Vlanif100] ip address 10.10.10.10 24 [HUAWEI-Vlanif100] dhcp select global [HUAWEI-Vlanif100] quit [HUAWEI] ip pool global1 [HUAWEI-ip-pool-global1] network 10.10.10.0 mask 24 [HUAWEI-ip-pool-global1] excluded-ip-address 10.10.10.11 10.10.10.20

DHCP clients on S series switch cannot detect IP address conflicts
Before a DHCP client binds an obtained IP address to a VLANIF interface, it proactively sends a gratuitous ARP packet to check for IP address conflict. The VLANIF interface does not have an IP address, so its protocol status cannot go Up. When the physical interface in the corresponding VLAN receives the gratuitous ARP packet with the conflicting IP address, it cannot send the packet to the CPU. As a result, the DHCP client cannot detect IP address conflict. To resolve this problem, configure the dhcp server ping function on the DHCP server to check for IP address conflict. When there is a large number of DHCP clients, this function requires a high cost, so you need to decide whether to use this function after thorough consideration.

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