Two IPSec Tunnels Destined To Different IP's With Same Subnet



  • I have a question.  I'm attempting to establish IPSec VPN Tunnels to AWS.  I've got one tunnel set up between my PFSense Firewall and AWS.  I have two different destination host IP's on AWS.  My initial VPN comes up and looks very stable.  When I attempt to start the second IPSec tunnel, it fails and doesn't throw any errors.

    My Setup looks like this.

    IPsec tunnel #1 = PFSense WAN @ x.x.x.227/28 <- My Static IP on my PFSense Firewall -> AWS Static IP @ x.x.x.224/32
    Remote Network = 10.5.0.0/16 <- Internal network of AWS - (This tunnel works fine bidirectionally.)

    IpSec tunnel #2 = PFSense WAN @ x.x.x.227/28 <- My Static IP on my PFSense Firewall -> AWS Static IP @ x.x.x.193/32
    Remote Network = 10.5.0.0/16 <- Internet Network of AWS - (This tunnel won't come up)

    Looking at this, it seems like due to both tunnels trying to use the same remote subnet, the second tunnel won't play nicely.  Is this correct?  Is this even possible or will I have to do something like NAT before IPSec and modify the AWS crypto map ACL to allow my public address?

    I'm trying to create redundant VPN tunnels from my firewall to AWS so that if one should fail, the other will continue to function.

    Thanks in advance


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