3Com Switch 8800 Configuration Guide
Chapter 13 DHCP Configuration
13-18
the DHCP server receives no response after sending all these packets, it considers the
IP address is not used by other devices in this network and assigns the IP address to
this DHCP client. Otherwise, it does not assign the IP address.
Perform the following configuration in system view.
Table 13-29
Configure parameters for DHCP server to send ping packets
Operation
Command
Set the maximum number of ping
packets the DHCP is allowed to send
dhcp server ping packets
number
Revert to the default maximum number
undo dhcp server ping packets
Set the maximum duration for the DHCP
server to wait for response to a ping
packet
dhcp server ping timeout
milliseconds
Revert to the default maximum duration
undo dhcp server ping timeout
By default, the DHCP server sends up to 2 ping packets to test an IP address and waits
for a response for up to 500 milliseconds before it sends another ping packet.
Note that the DHCP server detects address conflict by ping packets, whereas a DHCP
client does this by ARP packets.
13.3.12 Displaying and Debugging the DHCP Server
After the above configuration, yYou can execute the
display
command in any view to
display operating information about the DHCP server to verify your configuration, and
execute the
debugging
command to enable debugging for the DHCP server
Execute the following command in any view.
Table 13-30
Display the configuration information about the DHCP server
Operation
Command
Display the statistics about DHCP
address conflicts
display dhcp server conflict
{
all
|
ip
ip
-
address
}
Display information about lease-expired
addresses in DHCP address pool(s).
The lease-expired IP addresses in an
address pool are assigned to other
DHCP clients as needed if the address
pool runs out of its available IP
addresses
display dhcp server expired
{
ip
ip
-
address
|
pool
[
pool
-
name
] |
interface
[
vlan-interface
vlan
_
id
] |
all
}
Display the ranges of available
(unassigned) IP addresses in DHCP
address pools
display dhcp server free-ip