(Optional) Configuring the Alarm Function for IP Address Exhaustion

Context

To receive notifications about IP address exhaustion, configure the DHCP to generate alarms for IP address exhaustion.

Procedure

Configure the alarm function in an interface address pool.
1. Enter the system view.
```
system-view
```
2. Enter the interface or sub-interface view.
```
interface interface-type interface-number[.subinterface-number ]
```
  Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731S-H, S5731-S, S5731S-S, S6720-HI, S5732-H, S6730-H, S6730S-H, S6730-S, S6730S-S, S6720-EI, and S6720S-EI support sub-interfaces.
3. (Optional) On an Ethernet interface, run undo portswitch
  The interface is switched to Layer 3 mode.
  
  By default, an Ethernet interface works in Layer 2 mode.
  
  Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support switching between Layer 2 and Layer 3 modes.
4. Specify the percentage of alarms indicating the exhaustion of IP addresses and the percentage of clear alarms.
```
dhcp server alarm ip-used percentage alarm-resume-percentage alarm-percentage
```
  By default, the percentage of the alarms is 100%, and the percentage of the clear alarms is 50%.
Configure the alarm function 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. Specify the percentage of alarms indicating the exhaustion of IP addresses and the percentage of clear alarms.
  alarm ip-used percentage alarm-resume-percentage alarm-percentage
  By default, the percentage of the alarms is 100%, and the percentage of the clear alarms is 50%.