Sharing NAT Gateway which is already exisit with new VPC in the same account

Question

Hello,

I have VPC and it has NAT Gateway with EIP.
I am going to make a new VPC.

is there a way I can share the NAT in new vpc resource?

I am trying to use the same EIP address as the one with NAT.

I trying to find the way and test Peering. it doesn't work.

if it is possible, could you let me know how to in details

Thank you so much

Andrew Nicholls · Answer

As per previous answer you can't share a NAT Gateway via peering.

We have used transit gateways where we run multiple (~9) VPCs in a single account.

For us the cost savings make good sense and we can present a single set of 3x IP addresses for outbound egress.

No Transit Gateway

3x NAT Gateways (1 per AZ) x 9 VPCs @$0.059/hr = $1.593/hr = $1,146.96/month

Compared with

3x NAT Gateways @$0.059/hr = 0.177/hr = $127.44/month

9 x transit gateway attachments @$0.07/hr = $0.63/hr = $453.60/month

Of course this doesn't include data charges but these are not significant in our setup.

Brettski-AWS · Answer

No, you can't share a NAT Gateway via VPC Peering.

You can share a NAT Gateway when using Transit Gateway to link the VPCs together. However, there is additional cost there so that may not be an appropriate solution for you.

You could set up a proxy server in the first VPC and have applications in the second VPC access that proxy server and have it use the NAT Gateway. But again, that is additional cost and complexity for you so I wouldn't recommend that and it might not work for applications that can't be configured to use a proxy server.

Sharing NAT Gateway which is already exisit with new VPC in the same account

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