Each VPN connection has two tunnels. One tunnel is used as primary and the other is used as failover. The failover is used for high availability (HA) purposes when the primary goes down for maintenance. Both tunnels will send traffic to the customer gateway provided to Acquia. Acquia cannot remove the tunnels. If another gateway or tunnel is required, Acquia can create a second VPN connection, which will have two additional tunnels.
Each tunnel will have its own separate settings. Both tunnels will have the same Customer Endpoint External Address because they are linked to a single customer gateway.
External Address: The public IP address of the customer gateway provided to Acquia. This IP address will be same for both tunnels.
Internal Address: Link-local IP address that form the internal VPC transit net, which allow the endpoints to communicate with each other without the risk of an IP address collision between the customer and Acquia networks.
External Address: The public IP address of the tunnel endpoint at Acquia's end. The IP address will be different for each tunnel.
Internal Address: Link-local IP address that form the internal VPC transit net, which allow the endpoints to communicate with each other without the risk of an IP address collision between the customer and Acquia networks.
The following are the default settings. Some of the settings are adjustable on the customer end of the connection. Acquia's side will mirror the customer settings, which cannot be modified from the Acquia end of the connection. The following is a list of IKE configurations that Acquia supports.
Authentication Protocol: SHA-1 (default), SHA-2 (256), SHA2 (384), SHA2 (512)
Encryption Protocol: S-128 (default), S-258
Lifetime: 900 - 28,800 (default)
DH Group: Groups 2 (default), 14-24
Mode: main
Pre-Shared Key: Random. Acquia can customize or change if needed.
The following are the default settings. Some of the settings are adjustable on the customer end of the connection. Acquia's side will mirror the customer settings, which cannot be modified from the Acquia end of the connection. The following is a list of IPSEC configurations that Acquia supports.
Protocol: esp
Authentication Protocol: SHA-1 (default), SHA-2 (256), SHA2 (384), SHA2 (512)
Encryption Protocol: S-128 (default), S-258
Lifetime: 900-3600 (default)
DH Group: Groups 2 (default), 5, 14-24
Mode: tunnel
Clear DF Bit: true
Frag. before Enc.: true
TCP M Adjustment: 1379
Dead Peer Retries: 3
Dead Peer Interval (m): 10
I am having trouble setting up my VPN connection and the tunnels are failing to establish.
Note
Acquia Shield/Secure VPN does not currently support BGP (border gateway protocol).Tips to ensure your VPN tunnel is setup correctly:
Please review this image if you have any questions about the topology of a VPN tunnel to your Acquia Cloud servers.
Are you connected to Acquia Cloud, but it doesn't appear to be working? See our troubleshooting guide here: My VPN Tunnel is connected to Acquia Cloud, but is not working
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Wed Oct 22 2025 09:07:31 GMT+0000 (Coordinated Universal Time)