DFS management console showing unknown servers on SYSVOL replication group

If you ever saw unknown servers in SYSVOL replication group, event any of DFS Replication Group? Do you know why is reporting unknown and how do I remove the unknown servers from DFS replication group

Also Read: SYSVOL and NETLOGON not shared on Windows server 2016/2012 R2

Do you know why is reporting unknown Members on DFS replication group?

If there are unknown servers in SYSVOL replication group then that might be orphaned Domain Controller, these unknown servers are not anymore on your Active Directory Domain, Decommissioned Domain Controllers not cleaned up properly which is showing as unknown servers

This is same for all other DFS servers if you decommission any of DFS server which is part of DFS replication group or referral servers for DFS namespace, then you have to remove this as part of decommissioning, if not this server object will showing as unknown servers

Also Read: Why DFSR disk not showing correct free space

Is any issue if we have unknown servers on DFS Replication Group

There are no issues as these servers are used to replicate the date, servers should have been decommissioned and not used anymore

Is any issue if we have unknown servers on DFS folder Target

My understanding, there is no issues as DFS referral been disabled, if the membership status showing enable then still some users are trying to connect the box, you have to disable to avoid the impact

Also Read: Why DFS Referral list not showing all the DFS Servers?

Other Impact needs to be considered

If you are not replacing the the server for the location then the users from that location connect to the nearest DFS server as per the site configuration, this needs to considered

Also Read: Force DFS Replication/Force DFSR Members to Replicate on windows server 2008 and 2012

How to remove the unknown servers from DFS Replication on DFS management console

Open DFS management console
Select Replication
Select Domain System Volume
Right click the unknown member
Select Delete
Select OK

How to remove the unknown servers from DFS namespace on DFS management console

Open DFS management console
Select Namespaces (Domainname\Sysvol)
Select Folder Targets
Right click the Server
Select OK
Select Delete
Select OK

Also Read:DFS troubleshooting from Client end

Also check if any orphaned object in active directory which is causing the issue

Login to Any DC
Open ADSIEDIT.MSC
Expand below DFS Replication topology container
CN=Topology,CN=Domain System Volume,CN=DFSR-Globalsettings,CN=System,DC=Your Domain,DC=Domain Suffix
Check and delete old orphaned object under msDFSR-Member