IPsec
BGP
IKE Security
Tunnel
Explanations:
IPsec (Internet Protocol Security) is a suite of protocols designed to secure Internet Protocol (IP) communications. While it is used to establish a secure tunnel, the initial association between the virtual private gateway and the customer gateway using a Pre-Shared Key (PSK) primarily occurs in the IKE phase, not IPsec itself.
BGP (Border Gateway Protocol) is a standardized exterior gateway protocol used to exchange routing information between different networks. It does not establish associations between gateways but rather facilitates the routing of packets once the tunnels are established.
IKE (Internet Key Exchange) Security is the protocol that establishes the initial association between the virtual private gateway and customer gateway. IKE uses the Pre-Shared Key as part of its authentication process to create a secure communication channel before establishing the actual IPsec tunnel.
Tunnel refers to the encrypted connection established after the initial associations are made. While tunnels are an important concept in VPNs, they are not the initial association phase, which is performed by IKE.