Private IP address change, effect(s)?

Question

Hello All,  
  
What are the effects of changing the Private IP address within the EC2 Instance? I'm wondering what issues will occur and if even this _can_ be done, and if so what are the repercussions?  
We're trying to set up a site-to-site VPN with our company and they are wanting to change/map these IPs/CIDR Blocks.  
  
Is there any documentation (I'd be surprised if there wasn't) that talked about this?  
  
Thank you

AWS-User-5718909 · Answer

Hello,  
  
When EC2 instances are launched, the primary elastic network interface is assigned a reserved private IP address from the default VPC DHCP pool. The private IP address stays assigned to the network interface until it is deleted. The instance's primary network interface cannot be removed; it stays assigned to the instance until the instance is deleted. It is not possible to remove or change the private IP address of the primary network interface, but it is possible to add more private IP addresses to the network interface.  
  
Note: You can manually assign a static private IP address for your Windows network adapter, but if the network interface IP address and Windows adapter’s IP addresses don’t match, the network connection will not work.   
  
https://aws.amazon.com/premiumsupport/knowledge-center/static-private-ip-windows/  
https://aws.amazon.com/premiumsupport/knowledge-center/custom-private-primary-address-ec2/  
  
Thank you.

Private IP address change, effect(s)?

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