Resolver and Timeouts

Hi,

I have a problem with timeouts. If my network configuration is
correct, it works quite nicely. But if not, the timeout is around 5
minutes or so. How can I change this?

The problem being that e.g. I have a fresh board with a working kernel
image and I boot it in another environment where they have a different 
IP config and, most likely, DNS server.

Thanks for helping.

        uwe