Operation Manual – DHCP
H3C S3610&S5510 Series Ethernet Switches
Chapter 2 DHCP Server Configuration
2-15
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…
Use the command…
Remarks
Enter system view
system-view
—
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.
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.
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.
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.
I. Configuration prerequisites
Before performing this configuration, complete the following configuration on the DHCP
server:
z
Enable DHCP
z
Configure the DHCP address pool