dhcpcd is an useful tool to help you fix dhcp client settings without the need to use the X windows network configuration tools.
To install dhcpcd, just install
# apt-get install dhcpcd
Some application of dhcpcd.
Note 1: Don't let the DHCP program modified your /etc/resolv.conf
# dhcpcd -R eth1
Note 2: Getting your preferred IP Address from the dhcp server. This is especially useful in a small network like home network
# dhcpcd -k (release the dhcp release)
# dhcpcd -s xxx.xxx.xxx.xxx eth1
Note 3: Preventing DHCP from installing default route
# dhcpcd -k (release the dhcp release)
# dhcpcd -G xxx.xxx.xxx.xxx eth1
For more usages, you can visit the online man page for dhcpcd
