Your AD server should be doing the dhcp serving for the network not the router. Not only do the workstations get the correct ip info via dhcp but you can also configure the dhcp server to automatically update the dns server host records.
That's the thing, since I was brought into this situation - due to the previous Tech just randomly stringing the client along and then apparently dropping them - I have been trying to ascertain the issues without taking the network completely offline since the office itself is constantly busy with patients. Finding a permanent fix for an issue that should not be happening as the way the server and the workstations are set up is the the main goal at this point. Each time I am brought in I have to work out what was previously done. Apparently the Tech before had setup the workstations to have their IP addresses Static Per Workstation then out of the blue (according to the client) he switched it to auto after a certain period of time, once the client moved off DSL as their service provider to Comcast (and supposedly after one Microsoft Update causing major issues which there is no record of in any previous worklogs by the previous Tech - who really did not leave any detailed worklogs just simple "fixed network issue" with invoiced charges) is when the workstations started to have these DNS issues. So overall, at this moment I am trying to figure out what is causing these issues - especially since the Domain Controller seems to be properly configured with Active Directory finally in order since the original Tech did not properly add one Computer account that was having the main issues to the Active Directory (it being the examining room workstation - one of their critical computers that needed to be up during the day). Which took me at most 15 min to add and get running - even after the original Tech was claiming it was joining a nonexistant network that he simply tried fixing by renaming the network connection.
To be truthful, the situation I find myself in is due to the fact the Tech in question would randomly come in 'to fix a problem' and spend months letting the problem fester - now that he has disappeared once again, its something I have been pulled into. Frustrating mainly because I had no part in setting up this network and have to work backward with the limited time given by the client throughout the day to quickly patch the workstations to a working state.
Currently the three computers that have been having issues - by setting them to use the DNS settings I mentioned above, has resolved the issue of not able to \\servername to shares but \\ip.of.server (\\192.168.10.91 for example) to shares, but to me it is a temporary fix that needs to be permanently rectified other than as it has been done so far.
My best guess is the situation trailed off to this point after Comcast was introduced as the ISP, mainly going by what the client noticed happening to their network shortly after. I appreciate your feedback, just this situation for the client and myself is getting a bit frustrating.
Edited by Toten0Maske, 30 December 2014 - 09:28 AM.