AWS EC2 Instance unable to use NAT Gateway

Question

I has setup my AWS with VPC NAT gateway, subnet, Route Table as below diagram http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/vpc-nat-gateway.html

The different is my private subnet are create EC2 instance instead of Database Servers.

My problem is the EC2 instance in private subnet are failed to connnect to internet using NAT.

FYI, the EC2 instance in public subnet are able to connect internet using the instance EIP. Mean internet in public subnet working fine.

Please Help. Thanks

Have you gone through these troubleshooting steps in that page you linked to? http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/vpc-nat-gateway.html#nat-gateway-troubleshooting-no-internet-connection — Karen B, Jun 26 '16 at 16:17

score 0 · Answer 1 · answered Jun 26 '16 at 17:02

0

Make sure you disabled source/dest check on the NAT instance ('action' menu - 'networking')

answered Jun 26 '16 at 17:02

Putnik

1

The question appears to be about a NAT Gateway, not a NAT Instance. – Michael - sqlbot Jun 26 '16 at 18:05

score 0 · Answer 2 · answered Sep 07 '18 at 20:24

0

Verify if

1) Nat Gateway is created inside a public subnet.

2) Route tables of the private subnet/s is configured properly.

answered Sep 07 '18 at 20:24

Mohammad Ghonaim

score 0 · Answer 3 · answered Oct 11 '19 at 02:40

Check that the NAT gateway is in 'available' state.
Check that the route tables are configured correctly. NAT gateway must be in public subnet with a route that directs all internet traffic (i.e. 0.0.0.0/0) to internet gateway. Your private EC2 instance must be in private subnet with a route that directs all internet traffic (i.e. 0.0.0.0/0) to NAT gateway.
Check that the security groups for the private EC2 instance allows HTTP/HTTPS outbound internet traffic (0.0.0.0/0). if you are using PING, then also check ICMP is allowed (in addition to HTTP and HTTPS).

3 Answers3