HP VPN Firewall Appliances Network Management Configuration Guide

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address of the client. Removing an ARP entry manually does not remove the corresponding client's
IP-to-MAC binding.
To enable offline detection:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter interface view.
interface interface-type interface-number N/A
3. Enable offline detection.
dhcp server client-detect enable Disabled by default.
Enabling handling of Option 82
With Option 82 handling enabled, when the DHCP server receives a request with Option 82, it adds
Option 82 into the response.
If the server is configured to ignore Option 82, it assigns an IP address to the client without adding
Option 82 in the response message.
Configuration prerequisites
Before you perform this configuration, complete the following configurations on the DHCP server:
1. Enable DHCP.
2. Configure the DHCP address pool.
Enabling Option 82 handling
To enable the DHCP server to handle Option 82:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enable the server to handle
Option 82.
dhcp server relay information
enable
Optional.
Enabled by default.
To support Option 82 requires configuring both the DHCP server and relay agent (or the device enabled
with DHCP snooping).
Specifying the threshold for sending trap messages
Configuration prerequisites
Before you perform the configuration, use the snmp-agent target-host command to specify the
destination address of the trap messages. For more information about the command, see System
Management and Maintenance Command Reference.
Configuration procedure
A DHCP server sends trap messages to the network management server when one of the following items
reaches the specified threshold:
• The ratio of successfully allocated IP addresses to received DHCP requests
• The average IP address utilization of the address pool