The dhcp server excluded-ip-address command specifies the range of IP addresses that cannot be automatically assigned to clients from an interface address pool.
The undo dhcp server excluded-ip-address command deletes the specified range of IP addresses that cannot be automatically assigned to clients from an interface address pool.
By default, all IP addresses in an address pool can be automatically assigned to clients.
dhcp server excluded-ip-address start-ip-address [ end-ip-address ]
undo dhcp server excluded-ip-address start-ip-address [ end-ip-address ]
Parameter |
Description |
Value |
|---|---|---|
start-ip-address |
Specifies the start IP address of the IP address segment where addresses cannot be automatically assigned to clients. |
The value is in dotted decimal notation. |
end-ip-address |
Specifies the end IP address of the IP address segment where addresses cannot be automatically assigned to clients. If end-ip-address is not specified, only the IP address corresponding to start-ip-address cannot be automatically assigned. |
The value is in dotted decimal notation. end-ip-address and start-ip-address must be on the same network segment and end-ip-address must be larger than start-ip-address. |
Usage Scenario
The dhcp server excluded-ip-address command applies to DHCP servers. Fixed IP addresses are allocated to some specific hosts (such as the WWW server) on the network for a long time. If these hosts' IP addresses are overlapped with IP addresses in the address pool and the DHCP server allocates these overlapped IP addresses to other hosts, IP address conflicts may occur. To prevent such IP address conflicts, you need to exclude these IP addresses from being automatically assigned in the address pool.
You can run the dhcp server excluded-ip-address command to specify the IP addresses or the range of IP addresses that cannot be automatically assigned to clients in the interface address pool.
You can run the excluded-ip-address command to specify the IP addresses or the range of IP addresses that cannot be automatically assigned to clients in the global address pool.
Prerequisites
IP addresses in the interface address pool have been configured using the ip address command.
The DHCP server function has been enabled on the interface using the dhcp select interface command.
Precautions
You do not need to exclude the gateway address configured using the dhcp server gateway-list command from being automatically allocated. The device automatically adds the gateway address into the list of IP addresses that cannot be automatically allocated.
You do not need to exclude the IP address of a server's interface connecting to a client from being automatically allocated. The device automatically sets the status of the interface IP address to Conflict during address assignment.
<HUAWEI> system-view [HUAWEI] dhcp enable [HUAWEI] interface vlanif 100 [HUAWEI-Vlanif100] ip address 192.168.1.1 24 [HUAWEI-Vlanif100] dhcp select interface [HUAWEI-Vlanif100] dhcp server excluded-ip-address 192.168.1.1 192.168.1.20
<HUAWEI> system-view [HUAWEI] dhcp enable [HUAWEI] interface vlanif 100 [HUAWEI-Vlanif100] ip address 192.168.1.1 24 [HUAWEI-Vlanif100] dhcp select interface [HUAWEI-Vlanif100] dhcp server excluded-ip-address 192.168.1.30 Warning: The address is in used or conflict state. Are you sure to continue excluding the address?[Y/N]:y
<HUAWEI> system-view [HUAWEI] dhcp enable [HUAWEI] interface gigabitethernet 0/0/1 [HUAWEI-GigabitEthernet0/0/1] undo portswitch [HUAWEI-GigabitEthernet0/0/1] ip address 10.10.10.10 24 [HUAWEI-GigabitEthernet0/0/1] dhcp select interface [HUAWEI-GigabitEthernet0/0/1] dhcp server excluded-ip-address 10.10.10.11 10.10.10.20