repsTo And repsFrom

Some Posts are like Instant Coffee... You just make them in minutes. This is one of them... I was revising AD Replication and came across two terms (which I knew them already but then thought of just digging bit deep)

repsTo and repsFrom

repsTo: This will List all the Domain Controllers "TO" which a Particular Domain Controller will Replicate Changes or in other words will Send the Changes.

repsFrom: This will List all the Domain Controllers "FROM" which a Particular Domain Controller will Replicate Changes or in other words will Take the Changes.

You can of course jump to a conclusion here that this is quite relevant from the connection objects which will be created between these domain controller. But hold on. Do you that a connection object May or May Not Replicate ALL the Partitions viz Domain, Configuration and Schema

Don`t Trust me as Usual... I know... I have Proof as Usual :)

In My Lab, I have Three Domain Controllers

DC1, DC2 and DC3

All the Domain Controllers are in the Same Site and Its a Mesh Topology. So , you may see that every domain controller have a connection object with each domain controller

Which means, Since DC1 has a connection object with DC2 and DC3, It should Send and Receive Changes for all the partitions from both the domain controllers (DC2 and DC3) 

Lets Move to ADSIEDIT

Configuration Partition -> Properties

repsTo
repsFrom

You will get these attributes in the property of all the partitions (Domain, Configuration and Schema. You can although think that I said that these attributes will list the domain controllers with which this DC will replicate changes but here I am going into the property of a partition and not into the properties a particular domain controller. Check again. In ADSIEDIT, I am connected to DC1. So the Partition (Also known as NC) which we are currently viewing is hosted on DC1. So the attributes repsTo and repsFrom will be LOCAL to DC1 for this Partition.

In repsFrom, I can see two values.

Expanding them, It list the GUID`s of Domain Controllers (Which I can Verify from DNS)

The Two GUID`s Listed starts from "ef33" and "01ac"

Here you go... These GUID`s ("ef33" and "01ac") belongs to the Domain Controllers DC2 and DC3 Respectively.

Now lets check "repsTo"

Strange... Here I can see only one value

The GUID starting with "ef33" which is DC2

So, It means that "DC1" for "Configuration Partition", Will Send the Changes to DC2 Only whereas it can Receive Changes from DC2 Or/And DC3

~ Happy Reading