How to change DHCP config?
This doesn't really address your DHCP question (not sure what sysprop that would be), but it will fix your DNS issues. You can make an ASE script for it if you don't want to have to do it every time your DNS is changed by the provider.

Also, depending on how your DNS server is setup you may want to change the INT at the end of line one to "2" or "3" and add some other DNS servers for the rest of the internet (openDNS, google DNS, etc).

Open an adb shell or Terminal Emulator and type:

setprop ro.kernel.android.ndns 1
setprop net.eth0.dns1 152.xxx.xxx.xxx 


Alternatively, just throw the server(s) you want to resolve into /system/etc/hosts, like you would in a normal linux system.