[Samba] New sparsely connected replica graph (Improved KCC)

[Garming Sam]

Hi,

First of all, thanks for at least giving it a go. I think there's a few 
points of confusion though. Bridge all site links is enabled by default 
and should be enabled, otherwise you would need to manually specify 
site-link bridges (which is not recommended by Microsoft and not 
implemented in the KCC currently).

Is the new KCC running on all the DCs you mention?

Denis Cardon had a go briefly and found that he needed to specify a 
bridgehead before any connections were made. We weren't able to confirm, 
but it's possible that specifying a bridgehead may help.

http://samba.2283325.n4.nabble.com/More-KCC-patches-td4687011.html

So now to your topology, you mentioned that those connections should not 
have been removed? Do you have any specific reasons why? If everything 
was functioning, there should be even more connections missing than you 
see right now. The general idea of using the topology is to make sure 
that a site contains only 1 in and 1 out link across all the DCs within 
that site (as well as additional links within a site). The fact that 
everything was connected before was the cause of bandwidth issues.

The following would be similar to what I would actually expect:

SITEA
   Servers
        SDC1
           NTDS Settings   SDC2

        SDC2
           NTDS Settings   SDC1
                           PDC1

Default-First-Site-Name
   Servers
        PDC1
           NTDS Settings   PDC2
                           DDC1
                           SDC1
        PDC2
           NTDS Settings   PDC1

SITEB
   Servers
        DDC1
           NTDS Settings   DDC2
                           PDC1

         DDC2
           NTDS Settings   DDC1


Probably one of the most annoying things about replication and testing 
replication is that it doesn't necessarily trigger immediately. It's 
definitely not something which is straightforward to test, or implement.

Cheers,

Garming