(Optional) Configuring Fixed IP Addresses in an Address Pool

Context

A DHCP server leases IP addresses to clients. When the lease expires, the clients must apply for new IP addresses. To ensure stability, certain clients require fixed IP addresses. In this case, configure the DHCP server to allocate fixed IP addresses to these clients. The MAC addresses of these clients are then bound to fixed IP addresses. When such a client applies to the DHCP server for an IP address, the DHCP server searches the binding entries for the MAC address of the client and allocates the matched IP address to the client. DHCP static allocation prevents manual configuration errors and facilitates unified management.

Ensure that the bound IP address is not configured as the IP address that cannot be allocated.
IP addresses that are used can also be statically bound to MAC addresses or unbound from MAC addresses. When an IP address is statically bound to a MAC address, ensure that the MAC address to be bound is the same as the MAC address of the user who actually uses the IP address.
After an IP address is bound to a MAC address, the IP address does not expire. After an automatically allocated IP address is statically bound to a MAC address, the lease time of the IP address becomes unlimited. After the static binding between the IP address and the MAC address is deleted, the lease time of the IP address becomes the same as that configured in the address pool.

Procedure

Configure a fixed IP address in an interface address pool.
1. Enter the system view.
```
system-view
```
2. Enter the interface view.
```
interface interface-type interface-number
```
3. Bind an IP address to a MAC address so that the DHCP server allocates this IP address to only the device with this MAC address.
```
dhcp server static-bind ip-address ip-address mac-address mac-address [ description description ]
```
  By default, a DHCP server does not allocate fixed IP addresses to specified clients.
4. (Optional) Reserve an IP address for a DHCP client based on a MAC address.
```
dhcp server reserved ip-address mac
```
  By default, no IP address is reserved for a DHCP client.
Configure a fixed IP address in a global address pool.
1. Enter the system view.
```
system-view
```
2. Enter the global address pool view.
```
ip pool ip-pool-name
```
3. Bind an IP address to a MAC address so that the DHCP server allocates this IP address to only the device with this MAC address.
```
static-bind ip-address ip-address mac-address mac-address [ description description ]
```
  By default, a DHCP server does not allocate fixed IP addresses to specified clients.
4. (Optional) Reserve an IP address for a DHCP client based on a MAC address.
```
reserved ip-address mac
```
  By default, no IP address is reserved for a DHCP client.