Active Directory Disaster Recovery not working using secondary AD Server.

Hi,

For my disaster recovery, I am using Primary AD server 2012 with DNS which had all FSMO roles on it.
And Secondary AD Server 2008 R2 with DNS.
When my Primary is down I am getting below messages while opening AD console.

None of the AD console is working. I assigned Secondary AD server IP on preferred DNS on 2008 R2.
But still its not working.
on Event viewer I am getting below message.
 

1.What will be the best option for Disaster Recovery using Secondary server ?
2.Do I need to Sieze all he FSMO Roles and perform metadata cleanup with Ignoring Above messages ?

Thanks and Regards,
Nadeem A