... recommendations for highly available IPsec VPNs. This design is covered in depth in the High Availability for IPsec VPN Design Guide. HA Design Example High availability may be a customer requirement, ... is established, data traffic can flow in either direction, regardless of which side initiated the tunnel.VPN High Availability Customer requirements determine the type of high availability required ... Interface (VTI) design to support IPmc. For more information, see one of the following design guides (http://www.cisco.com/go/srnd): • Point-to-Point GRE over IPsec VPN Design Guide • Dynamic...