Is that possible?

Our servers are in JHB, we're about 400km away. All branches go to HQ through fire-obtic cables. Thus, we have a WAN (I think) with some kind of internet connection sharing? I'm just grabbing here, but I think this is how the setup is.

If I don't use the DNS servers that are installed on my system at the moment, can I still see my local servers??

I hate network issues like this...