Unable to logon to remote desktop services when primary DC is down

Question

Unable to logon to remote desktop services when primary DC is down

Rob Nicholson 66

My client has a simple Azure RDS setup: single RDS app server (serving up desktop), file server and two domain controllers. I installed updates on the primary domain controller over the weekend but failed - the console didn't come back up. It's a core installation, i.e. no desktop. I decided to leave it overnight to see if it finally restarted.

However, this morning, nobody is able to logon to the RDS desktop remotely. The primary DC still hadn't restarted after updates. I've manually restarted at and all is well but we've got two domain controllers for redundancy and this very reason (well partially, mainly so we've got AD duplicated).

RD Licensing is running on DC01 but it's also running on DC02.

Any ideas what component is still relying on the primary DC? BTW - I was able to logon to the RDS server via my remote control software so the domain logon itself appeared to be fine. I didn't have much time to diagnose as needed to get the service back up and running.

BrianLDVS 1 Reputation point

2021-08-18T15:04:05.033+00:00

Did you find a resolution to this?
We have a similar issue where one of our DCs are off overnight to save money on AWS charges.
Recently someone tried to connect when the DC1 was off and they were able to connect but with a time limit of one hour.
IIn troubleshooting, i found that the license server could not bind to AD. Once i booted DC2 and restarted the license service everything was fine.
TCP/IP for the TS and all DCs are consistent, the TS has DC2 as the first dns in it's list.
I am baffled.
Here are the FSMO roles
Schema master DC19-1.company.local
Domain naming master DC19-1.company.local
PDC DC19-2.company.local
RID pool manager DC19-2.company.local
Infrastructure master DC19-1.company.local
Rob Nicholson 66 Reputation points

2021-08-18T16:14:05.417+00:00

JHi Brian,

That sounds like a slightly different issue around licensing. Was the RDS licensing server only running on DC1 and that was down? We have RDS licensing installed on both DCs.

I haven't dug into the logs or tried to repeat the problem as I have to arrange downtime for several hours, probably over a weekend.

The feeling is that something in the RDS stack needs access to one or more of the FSMO roles.
BrianLDVS 1 Reputation point

2021-08-18T16:42:14.147+00:00

Our license server is installed on the TS.
I concur totally, It has to be some dependency on one of the FSMO roles, either Schema, Domain Naming or Infrastructure Master.
I scoured the web and only found your blog.
Rob Nicholson 66 Reputation points

2021-08-18T20:59:02.413+00:00

Yes me too - I could find very little on this subject. In fact, resources for Remote Desktop Services is light on the ground generally. As a total aside, we've got a really weird problem from one app saving to redirected drives. Firefox also struggles to download to them. Found zero on that subject either :-(
BrianLDVS 1 Reputation point

2021-08-19T15:05:11.877+00:00

Ours did end up being DNS. Found that the dns service was throwing errors so basically the TS could not resolve anything if the DC1 was offline.
Once i restarted DC2's DNS service, the logs cleared and all was back to normal.

1 answer

Your answer

BrianLDVS 1 Reputation point

2021-08-18T15:04:05.033+00:00

Did you find a resolution to this?
We have a similar issue where one of our DCs are off overnight to save money on AWS charges.
Recently someone tried to connect when the DC1 was off and they were able to connect but with a time limit of one hour.
IIn troubleshooting, i found that the license server could not bind to AD. Once i booted DC2 and restarted the license service everything was fine.
TCP/IP for the TS and all DCs are consistent, the TS has DC2 as the first dns in it's list.
I am baffled.
Here are the FSMO roles
Schema master DC19-1.company.local
Domain naming master DC19-1.company.local
PDC DC19-2.company.local
RID pool manager DC19-2.company.local
Infrastructure master DC19-1.company.local
Rob Nicholson 66 Reputation points

2021-08-18T16:14:05.417+00:00

JHi Brian,

That sounds like a slightly different issue around licensing. Was the RDS licensing server only running on DC1 and that was down? We have RDS licensing installed on both DCs.

I haven't dug into the logs or tried to repeat the problem as I have to arrange downtime for several hours, probably over a weekend.

The feeling is that something in the RDS stack needs access to one or more of the FSMO roles.
BrianLDVS 1 Reputation point

2021-08-18T16:42:14.147+00:00

Our license server is installed on the TS.
I concur totally, It has to be some dependency on one of the FSMO roles, either Schema, Domain Naming or Infrastructure Master.
I scoured the web and only found your blog.
Rob Nicholson 66 Reputation points

2021-08-18T20:59:02.413+00:00

Yes me too - I could find very little on this subject. In fact, resources for Remote Desktop Services is light on the ground generally. As a total aside, we've got a really weird problem from one app saving to redirected drives. Firefox also struggles to download to them. Found zero on that subject either :-(
BrianLDVS 1 Reputation point

2021-08-19T15:05:11.877+00:00

Ours did end up being DNS. Found that the dns service was throwing errors so basically the TS could not resolve anything if the DC1 was offline.
Once i restarted DC2's DNS service, the logs cleared and all was back to normal.

Answer 1

Devaraj G 2,096 Volunteer Moderator

Hi Thanks for the post.

Sounds like a DNS issue.

What's your DNS configuration on both the DCs? Do Ipconfig /all on DCs and post
What's the output of DCDIAG /v /c ? can you please post.

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Unable to logon to remote desktop services when primary DC is down

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