Additional DC not functioning if the Primary DC is down !!

Dashrender

@IT-ADMIN

If possible, please show the above panel for DC1 next to DC2

IT-ADMIN

@IT-ADMIN said:

i have a question please : do i have an issue or not, in another word: does DC1 (who has FSMO) should be online in order for DC2 to work properly or it is not a condition ???

That is not a requirement.
and because you are having problems when you turn off DC1, it appears that your DC2 is broken.

ah now i can see, so i have an issue here, damn glad to know that lol

IT-ADMIN

for the IP setting of DC1, unfortunately i'm home now, but i know its setting very well

DC1 :
IP : 192.168.15.250
Subnet: 255.255.255.0
gatway : 192.168.15.1

P DNS : 192.168.15.250
S DNS : 192.168.15.1

IT-ADMIN

the 2 site are connected via VPN

Dashrender

OK a possible huge issue is that you are pointing your secondary DNS to x.x.x.1, which is your default gateway, and unless you're using a Domain Controller as a default gateway is a very bad idea.

Windows machines should only ever point to your own DNS servers, more specifically, Windows DNS servers, assuming they are the backbone of your internal network.

If you put something like Google's DNS (8.8.8.8) as a secondary and the machine flips over to using that DNS server, that computer will never find your domain again until it's force to flip back, which will only happen on a reboot or a loss of internet connectivity.

Assuming DC2 is
IP 192.168.1.249
Subnet 255.255.255.0
DF 192.168.1.1
DNS1 192.168.1.249
DNS2 192.168.1.1 (change this to DC1 IP address)

I wonder if your DNS is working on DC2.

Dashrender

While both servers are on the network, Open DNS applet. Like ADUC switch to DC2. Check the DNS entries - are they there?
You can open another DNS applet and point it to DC1, then compare. They should be identical.

Dashrender

Also, while you're at it, Open a command prompt on DC2 and run dcdiag

IT-ADMIN

sorry guys, it is 1.35 AM, i have to sleep now
to be continued ...

scottalanmiller

@IT-ADMIN said:

sorry guys, it is 1.35 AM, i have to sleep now
to be continued ...

2:30 am here. Still going.

Dashrender

@scottalanmiller said:

@IT-ADMIN said:

sorry guys, it is 1.35 AM, i have to sleep now
to be continued ...

2:30 am here. Still going.

Crazy man.

scottalanmiller

3:20am .... calling it a night.

IT-ADMIN

this is DC1 ip setting :

scottalanmiller

If you have a second DC, the secondary DNS should point there rather than to the gateway.

Dashrender

@scottalanmiller said:

If you have a second DC, the secondary DNS should point there rather than to the gateway.

If you don't have a second DC, then it should be blank.