DNSMasq takes less than 5 minutes to configure and can save you a mountain of time troubleshooting. There could be a number of reasons you are experiencing this error. Do you have access to manage/edit the DHCP scope?
DNSMasq alleviates the need to make changes to the entire scope of the DHCP, I would recommend trying DNSMasq as it has helped many others in the past. DNSMasq involves the installation from apt-get, and a single configuration file, and we already created the template for you in the wiki, you copy and paste and change the ip address information to match that of your location.
Continuing any further without permission of your Network engineer/manager is NOT recommended. You MUST edit the settings at the DHCP server in order for your server to be seen by your network properly.