[Samba] samba 4.5.12 -- drs showrepl only 3 DCs?

[C.Kindler]

Hello,

updated from samba-4.4.14 to samba-4.5.12 the output from one DC
"samba-tool drs showrepl" does not show all 4 DC:
@DC02: no outbound  and inbound neigbour to DC04
@DC04: no outbound  and inbound neigbour to DC02
@DC01 and DC03 are shown all 3 neigbours:

- How to fix it?
I tried manually replicate, but this works only for some minutes... Luckily
the login part is working...



--
output from @DC2:
==== KCC CONNECTION OBJECTS ====

Connection --
        Connection name: 981ad8a8-9549-4013-a467-5fe3b52b5f0e
        Enabled        : TRUE
        Server DNS name : DC01.ad.mydomain.net
        Server DN name  : CN=NTDS
Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=ad,DC=mydomain,DC=net
                TransportType: RPC
                options: 0x00000001
Warning: No NC replicated for Connection!
Connection --
        Connection name: ea5261d8-67e4-497c-aa7c-118da0b95791
        Enabled        : TRUE
        Server DNS name : DC03.ad.mydomain.net
        Server DN name  : CN=NTDS
Settings,CN=DC03,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=ad,DC=mydomain,DC=net
                TransportType: RPC
                options: 0x00000001
Warning: No NC replicated for Connection!



output from  DC01
==== KCC CONNECTION OBJECTS ====

Connection --
        Connection name: 1a500d9c-6035-4c4f-90ca-7a2e4517850f
        Enabled        : TRUE
        Server DNS name : DC03.ad.wuestenrot.at
        Server DN name  : CN=NTDS
Settings,CN=DC03,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=ad,DC=mydomain,DC=net
                TransportType: RPC
                options: 0x00000001
Warning: No NC replicated for Connection!
Connection --
        Connection name: 1d7ab798-0ee9-4735-af58-ecbd450ade14
        Enabled        : TRUE
        Server DNS name : DC02.ad.mydomain.net
        Server DN name  : CN=NTDS
Settings,CN=DC02,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=ad,DC=mydomain,DC=net
                TransportType: RPC
                options: 0x00000001
Warning: No NC replicated for Connection!
Connection --
        Connection name: 8496b819-e395-49a7-854b-78ed80ec58f6
        Enabled        : TRUE
        Server DNS name : DC04.ad.mydomain.net
        Server DN name  : CN=NTDS
Settings,CN=DC04,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=ad,DC=mydomain,DC=net
                TransportType: RPC
                options: 0x00000001
Warning: No NC replicated for Connection!