R3721-F3210-F3171-HP High-End Firewalls Network Management Configuration Guide-6PW101

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NOTE:
W
ith the unauthorized DHCP server detection enabled, the firewall logs each detected DHCP server once.
The administrator can use the log information to find unauthorized DHCP servers.
Configuring IP address conflict detection
With IP address conflict detection enabled, the DHCP server pings each IP address to be assigned by
using ICMP. If the server receives a response within the specified period, the server selects and pings
another IP address. If not, the server pings the IP addresses once again until the specified number of ping
packets are sent. If still no response is received, the server assigns the IP address to the requesting client
(The DHCP client probes the IP address by sending gratuitous ARP packets).
To configure IP address conflict detection:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Specify the number of ping
packets.
dhcp server ping packets
number
Optional.
One ping packet by default.
The value 0 indicates that no ping
operation is performed.
3. Configure a timeout waiting
for ping responses.
dhcp server ping timeout
milliseconds
Optional.
500 ms by default.
The value 0 indicates that no ping
operation is performed.
Enabling Option 82 handling
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 will assign an IP address to the client without adding
Option 82 in the response message.
Configuration prerequisites
Before performing this configuration, complete the following configuration on the DHCP server:
• Enable DHCP
• Configure the DHCP address pool
Enable 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.