Following this guide, I have successfully (I think) created a connection between my Watchguard physical VPN and an Amazon-VPC with a VPN attached to it but I cannot ping my EC-2.
Amazon is setup as follows:
My VPC has a VPN with a customer gateway(75.75.x.x, my office), and a virtual gateway. The VPC also has a private subnet of (192.168.5.0/24) and an ec-2 in that subnet (192.168.5.40). My ACL's are set to allow all traffic in and out. My security group is set to allow all traffic in and out, as well as ICMP.
My Route table is set up as:
Destination: 192.168.5.0/24
Target: local
Status: Active
Propagated: No
Destination: 192.168.x.0/24 (x = 0-4)
Target: Virtual Gateway
Status: Active
Propagated: Yes
My static routes on the amazon vpn are:
192.168.0.0/24
192.168.1.0/24
192.168.2.0/24
192.168.4.0/24.
(These are the subnets in my office.)
Edit* In order to keep the connection alive I had to tell phase 1 to re-connect every hour and turn off NAT. Now I am getting consistent traffic flowing in, but not out to Amazon from my watchguard. I have made a static hop from 192.168.5.0/24 to the virtual Private gateway, per Amazons suggestion on my watchguard device.