I got a preconfigured debian image that gets it's network configuration by DHCP, however the DNS server is/was fixed to 220.127.116.11. This was configured using /etc/resolv.conf, so I deleted all the entries there. /etc/dhcpc/resolv.conf contains the DNS server I would like to use, however this DNS server isn't used by the system. How do I activate the usage of the DNS server provided by DHCP? Thanks!
ln -sf /etc/dhcpc/resolv.conf /etc/resolv.conf
The system will look only in /etc/resolv.conf for nameservers. What the above command does is it creates a symbolic link /etc/resolv.conf to the file /etc/dhcpc/resolv.conf. In effect, when opening /etc/resolv.conf you actually open the file /etc/dhcpc/resolv.conf. And I take it that file contains the information you want your system to use.
I ended up installing
isc-dhcp-client, seems to fix the problem. Thanks for all the other hints, though!