IP Cutover

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IP Cutover is needed when the Base machine is CentOS-6 and the VM is CentOS-7

Lets consider this server running in CentOS 6 ,and now the application team is asking to cut-over , they will come to us for the cut over when we have the new and the old server ready .

netutils02-eq


This IP is reachable from our work station.

We will need to disable the IP address in this server and enable the IP address in another server new server .

We need to shutdown the interface first .

$ /sbin/ifdown ens192

Before that we need to go to checkMK and make sure this server is configured for downtime . The two servers will have different IP addresses though they might be running in the same network.

once the interface is down we will not be able to ping this IP address from our workstation. 

Once after checking the checkMK if the server CentOS is maked for downtime and then bring down the interface with the above command, irrespective whether it is the Physical server or a Virtual server, 

Once you disable the interface your IP address will be inaccessible from anywhere . And now you will have to enable the IP address in the newly build server . 

We need to go to our VirtualCenter . And we need to search for the new server which they have build as a replacement for this old server 

we will configure the same IP address on the new server but shall keep the Public IP address in disconnected state.  so there wouldn't be any conflict over the Public IP over the network as far as our old server is live. 

We will go to Actions in the new server  -- Actions -- edit settings 


check the ticks for connected and connect At power on . with this the Public IP configured on this server will be enabled. And that IP address will be same as our old public IP address. 


Roll Back

$ cd /etc/sysconfig/network-scripts/

ifcfg-ens192   -- rename this file open the file comment out all the entries . once you have commented out all the lines. restart the network service once 

after restarting the network service ensure the public interface is not coming up.




















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