PRFV-5637 DNS response time could not be checked on the following nodes

If you are getting following error on the installation of the Oracle Grid Infrastructure Installation:

PRFV-5637 DNS response time could not be checked on the fokllowing nodes
- Cause: An attempt to check DNS response time for unreachable node failed on nodes specified
- Action: Make sure that "nslookup" command exists on the nodes listed and the user executing the CVU check has execute privilege for it.

The problem is strongly related to the OS-level's bind-utils package.

The solution is to do the following as the root user:

After Grid Infrastructure deinstallation: [INS-40912] Virtual host name assigned to another system on the network

If you have ever installed a Oracle Grid Infrastructure Software and deinstalled it and again tried to install it, then you might run in the error [INS-40912] Virtual host name assigned to another system on the network.

If you check to ping node2 from node1 or node1 from node2 through their virtual IP's then that will succeed. This is wrong cause the nodes should NOT be pingable BEFORE the installation of the Grid Infrastructure.

In my case an alias was created for my interface NIC with the use of the virtual IP (which came with the previous installation):

eth0:2 Link encap:Ethernet  HWaddr 00:50:56:B9:0E:AA
       inet addr:10.200.11.159  Bcast:10.200.11.255  Mask:255.255.252.0
       UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
       Interrupt:19 Base address:0x2000

So in that case just do:

ifconfig eth0:2 down