Loss of Server connectivity

Question

I'm struggling with our server since last night when the MD updated Sage to a newer version and restarted the server (Server 2016).

Since then none of the PCs can access any information on the server however things like DHCP are working.

Errors on all client PCs: -

• Entering the IP address of the server into File Explorer will not connect. If I diagnose the network error then the troubleshooter also errors "an unexpected error"
• If I try and run GPUpdate /force this errors "The processing of the group policy failed, Windows could not resolve the computer name"

However, if run PortQryv2 on the IP address of the server it returns the DNS name (server in question controls DNS)

What PortQry does show is that the RPC Endpoint Mapper did not respond.

i.e.
IP address resolved to {servername}

querying...

TCP Port 135 (epmap service); LISTENING

Using ephemeral source port
Querying Endpoint Mapper Database....
Server's response:

RPC Endpoint Mapper did not respond
TCP port 135 is FILTERED

I've checked the server and RPC Endpoint Mapper and it is running however I can't change any settings on it.

-= Additional Edit =-

I had a new PC which I connected to the domain without issues, it accepted the user and created a record for the PC in the Active Directory
It then rebooted to complete the process but on logon it wouldn't sign on (cannot find domain errors)

It was left an half an hour and now it's starting to logon

It grabbed the policy settings, including the mapped drives at some point but now it has the same issue as all the other PCs with regards using the drives and taking GPO updates.

Answer 1

From what you described it sounds like broken DNS, but dcdiag reports DNS is functional. I'd also check that all members (including domain controller) got the domain network profile.

Answer 2

There is only one server rather than 3

Answer 3

Generally looks Ok but PC-Derrick has google public DNS server addresses. Domain controller and all members must use the static ip address listed for DNS and no others such as router or public DNS. So remove the public addresses from the DHCP server scope, then clients should do ipconfig /renew

--please don't forget to upvote and Accept as answer if the reply is helpful--

Answer 4

Sorry for the late reply, I've changed the DHCP setting to remove the 8.8.8.8 and 8.8.4.4 fall back addresses.

On all the site PCs
\10.0.0.3 still does not access the server shares *2
\ycrserver1 still does not access the server shares *1

On the new PC
\10.0.0.3 still does not access the server shares
\ycrserver1 can access the server share

1 - This errors "0x80004005 - Restricted"
2 - This errors "0x80070035 - The network path was not found"

Edit - Additional

Removing 8.8.8.8 and 8.8.4.4 from DHCP stopped anything online outside the building from working.

Answer 5

There seems to be more and more wrong with the server.

The Group Policy editor error some things are missing despite working before
I'm logged in as the admin user and I keep getting access denied when trying to do things - i.e. copy back the admx / adml files into the policy folder.

I'm about one more issue short of just formatting the drive and getting in my car to go home.