http://cloudstack.apache.org/docs/en-US/Apache_CloudStack/4.2.0/html/Installation_Guide/vpn.html#site-to-site-vpnstates:
- *CIDR list*: The guest CIDR list of the remote subnets. Enter a CIDR or a comma-separated list of CIDRs. Ensure that a guest CIDR list is not overlapped with the VPC’s CIDR, or another guest CIDR. The CIDR must be RFC1918-compliant. I'm not a network guy, so excuse the question if it's obvious, but if a customer only has public ip's on their end, why is rfc1918 required? -- Erik Weber
