I have one Splunk server sitting in a VPC with no internet connectivity and I want to use Spunk App for AWS to collect information about my EC2 instances. The App doesn't seem to support tunneling and I'm not sure what my other options are.
Make sure your security group and Net ACL allows you connect to internet. Make sure you have a Gateway configured as well.
Can I use a forwarder for this?
That's not possible for due to security requirements. There's no direct internet connection on the Splunk host.