Configuring Ip Address Conflict Detection; Configuring The Handling Mode For Option - H3C S7500E Series Operation Manual

Operation Manual – DHCP
H3C S7500E Series Ethernet Switches
Enter system view
Enable unauthorized
DHCP server detection
Note:
With the unauthorized DHCP server detection enabled, the device puts a record once
for each DHCP server. The administrator needs to find unauthorized DHCP servers
from the log information.

2.6.3 Configuring IP Address Conflict Detection

To avoid IP address conflicts, the DHCP server checks whether the address to be
assigned is in use via sending ping packets.
The DHCP server pings the IP address to be assigned using ICMP. If the server gets a
response within the specified period, the server will ping another IP address; otherwise,
the server will ping the IP addresses once again until the specified number of ping
packets are sent. If still no response, the server will assign the IP address to the
requesting client (The DHCP client probes the IP address by sending gratuitous ARP
packets).
Follow these steps to configure IP address conflict detection:
To do...
Enter system view
Specify the number of
ping packets
Configure a timeout
waiting for ping
responses

2.7 Configuring the Handling Mode for Option 82

When the DHCP server receives a message with Option 82, if the server is configured
to handle Option 82, it will return a response message carrying Option 82 to assign an
IP address to the requesting client.
To do... Use the command...
system-view
dhcp server detect
Use the command...
system-view
dhcp server ping
packets number
dhcp server ping
timeout milliseconds
Chapter 2 DHCP Server Configuration
—
Optional
One ping packet by default.
The value 0 indicates that no
ping operation is performed.
Optional
500 ms by default.
The value 0 indicates that no
ping operation is performed.
2-15
Remarks
—
Required
Disabled by default.
Remarks