New Active Directory Domain Services Connection

[charlie4872]

I have a domain controller in a site that is no longer able to communicate or replicate out to other DC's. My question is can I add a new AD Site connection or AD replication partner to a new DC in a nearby site to get replication going again? The server listed now is the "<Automatically Generated>" connection which is to a sever it cannot reach. It looks like communication has been lost for a couple days now. Thanks in advance!

[#2]

Hi @charlie4872,

In your position, I would first look to see why this particular DC is no longer replicating to the others - are there network problems at the site, OS problems with the DC itself etc? If your not familiar, the Active Directory File replication tool is a handy GUI to identify replication issues between different domain controllers 

https://www.microsoft.com/en-us/download/details.aspx?id=30005

Alternatively, the repadmin cmd is also very powerful at getting at the problem of replication issues. 

https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/cc...

You can look at trying to add new sites and get DC's to try and reach the problem DC, but I tend to find it better to get to the root cause rather than add more moving parts to the mix.

Hope this helps,

Mark

[#3]

Thanks for the reply Mark. The issue is a routing problem that is preventing any TCP connections from the problem site to the site where the Auto Generated replication partner is. So until that is resolved I was thinking I could add a new replication partner from another nearby site to have replication continue for the time being until the Auto Generated site is back up and running.

[#4]

Thanks for the extra information @charlie4872 

This is just me, but I tend to avoid doing any big changes to AD (like adding a new DC or setting up a new site) if all DCs in the domain aren't in a healthy replication state - this is probably an over-abundance of caution on my part, but having had replication issues compounded by extra changes I've made before I tend to double-check.

If the TCP issue isn't going to be fixed soon (like the next couple of days) then I guess you could spin up a new DC at another site and create a new site. Off the top of my head, the working DC (I'm assuming this one has all of the FSMO roles?) should replicate all relevant data for the stricken DC to the new DC to find it and add it as a replication partner. I'd personally want to test this in a lab first as I feel sure there might be some provisos/extra steps that I can't think of right now. 

Sorry, not very helpful I'm afraid!