H3C S7500 Series Ethernet Switches Operation Manual

Operation Manual – DHCP
H3C S7500 Series Ethernet Switches Chapter 2
DHCP Server Configuration
2-17
To do… Use the command… Remarks
Enter system view
system-view
—
Enable the private DHCP
server detecting function
dhcp server detect
Required
By default, the private
DHCP server detecting
function is disabled
2.4.3 Configuring IP Address Detecting
To avoid IP address conflicts caused by assigning the same IP address to multiple
DHCP clients simultaneously, you can configure a DHCP server to detect an IP
address before it assigns the address to a DHCP client.
IP address detecting is achieved by performing ping operations. To detect whether an
IP address is currently in use, the DHCP server sends an ICMP packet with the IP
address to be assigned as the destination and waits for a response. If the DHCP
server receives no response within a specified time, it resends an ICMP packet. This
procedure repeats until the DHCP server receives a response or the number of the
sent ICMP packets reaches the specified maximum number. The DHCP server
assigns the IP address to the DHCP client only when no response is received during
the whole course, thus ensuring that an IP address is assigned to one DHCP client
exclusively.
Follow these steps to configure IP address detecting:
To do… Use the command… Remarks
Enter system view
system-view
—
Set the maximum number
of ICMP packets a DHCP
server sends in a ping test
dhcp server ping
packets number
Optional
By default, a DHCP server
performs the ping operation
twice to test an IP address
Set the response timeout
time of each ICMP packet
dhcp server ping
timeout milliseconds
Optional
The default timeout time is
500 milliseconds