Huawei Quidway S5600 Series Operation Manual page 653

Operation Manual - DHCP
Quidway S5600 Series Ethernet Switches-Release 1510
2.4.2 Configuring Private DHCP Server Detecting
A private DHCP server on a network also answers IP address request packets and
assigns IP addresses to DHCP clients. However, the IP addresses they assigned may
conflict with those of other hosts. As a result, users cannot normally access networks.
This kind of DHCP servers are known as private DHCP servers.
With the private DHCP server detecting function enabled, when a DHCP client sends
the DHCP-REQUEST packet, the DHCP server tracks the information (such as the IP
addresses and interfaces) of DHCP servers to enable the administrator to detect
private DHCP servers in time and take proper measures.
Table 2-20 Enable detection of a private DHCP server
Operation
Enter system view
Enable the private
DHCP
detecting function
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.
Table 2-21 Configure IP address detecting
Enter system view
system-view
server
dhcp server detect
Operation
system-view
Huawei Technologies Proprietary
Chapter 2 DHCP Server Configuration
Command
Command
2-23
Description
—
Required
By default, the private DHCP
server detecting function is
disabled
Description
—