[Samba] Samba4 Secondary DC as Backup DC (redundancy)

[Rowland Penny]

On 23/06/15 18:58, Daniel Carrasco Marín wrote:
> Hi,
>
> I've sucessfull created a secondary DC using the wiki manual (
> https://wiki.samba.org/index.php/Join_a_domain_as_a_DC), and is working
> perfectly, user and groups are synced on both and I can use any of them for
> login using clients like Owncloud, Prosody, python scripts...
>
> Now my question is: ¿how I can use that secondary DC as backup when the
> main fails?.
>
> I've tried to disable the main AD daemon but clients don't try to connet to
> secondary DC, then all fails...
>
> Greetings and Thanks!!

OK, how do the clients get their ipaddress etc, is this by DHCP or do 
they have static addresses ?

If it is by DHCP, then the dhcp server needs to push out both DCs as 
nameservers, if static, then each client needs to be set to use both DCs 
as nameservers.

The DCs need to be set to use each other as nameservers, falling back to 
themselves in case of failure i.e. /etc/resolv.conf needs to be this:

search samdom.example.com
nameserver 192.168.0.3
nameserver 192.168.0.2

Where 'samdom.example.com' is your domain name
192.168.0.3 is the other DC
192.168.0.2 is the DC this /etc/resolv.conf is on

Swap the two nameserver on the other DC.

Rowland