19. DHCP
Client
MN700004 Rev 01
240
form of this command stops the DHCP client and restores the IP address, subnet mask and IP
gateway to their default values (using the command
ip address
).
By default, the dynamic address allocation is enabled.
To see the allocated IP address, use the
show ip
command in Privileged (Enable) mode.
Command Syntax
device-name
(config)#
ip address dhcp
[
A.B.C.D
]
device-name
(config)#
no ip address dhcp
Argument Description
A.B.C.D
The requested IP address.
Changing the DHCPDISCOVER Messages Retransmission
Timeout
The
dhcp-client discover-rto
command, in Global Configuration mode, defines the
maximum time that the DHCP client is allowed to be active and to send DHCPDISCOVER
frames. By default, the DHCPDISCOVER timeout is disabled.
When the DHCP client lauches, it attempts to negotiate an IP address from the DHCP server.
If, however, the IP address has not been received after the first attempt, the DHCP client will
keep re-sending the request at predefined time intervals until it eventually manages to
negotiate an IP address. The second request will be send one second after the initial one and
for each subsequent request, the time interval will increase exponentially by the factor of two
(2, 4, 8, 16, 32, 64) until the limiting value of 64 seconds is reached. From this point onward,
the DHCP client proceeds by sending its requests at 64-second intervals.
The
no
form of this command disables the retransmission timeout, i.e. the DHCP client will
keep sending requests until it negotiates an IP address.
Command Syntax
device-name
(config)#
dhcp-client discover-rto
<
time
>
device-name
(config)#
no
dhcp-client discover-rto
Argument Description
time
The DHCPDISCOVER message retransmission timeout in range of <1-32> minutes.
Saving the Configuration File (Boot File)
The
dhcp-client save-config
command, in Global Configuration mode, enables or disables
the saving of the configuration file that is loaded by the TFTP client.
By default, this feature is disabled.