I'm very new to AWS and we are moving our infrastructure to the cloud.
I've setup a Site-2-Site VPN which works with 1 Subnet (Availability Group). But not the other 2.
3 Subnets: EU-West-1a, EU-West-1b, EU-West-1c (172.31.16.0/20, 172.31.32.0/20, 172.31.0.0/20)
Network ACL: Associated with above 3 subnets.
Route Table: All 3 Subnets without explicit association
Internet Gateway: Attached to VPC
VPC: CIDR: 172.31.0.0/16
Instances connected to same Security Group and VPC
The Instances in different Zones can communicate with each other - But not to the customer's LAN. Only instances which can communicate with customers LAN are in the EU-West-1c Zone.
There has to be something obvious I'm missing. Has anyone came across this before could shed some light on this for me?
Its not a requirement that they should be in seperate zones and i could easily setup the servers in the same Zone. Its more a "why is this not working" as im sure at some stage this will be a requirement somewhere and i'd like to know the answer to resolve.
