services.strongswan-swanctl.swanctl.connections.<name>.children.<name>.mode

IPsec Mode to establish CHILD_SA with.

• tunnel negotiates the CHILD_SA in IPsec Tunnel Mode,
• whereas transport uses IPsec Transport Mode.
• transport_proxy signifying the special Mobile IPv6 Transport Proxy Mode.
• beet is the Bound End to End Tunnel mixture mode, working with fixed inner addresses without the need to include them in each packet.
• Both transport and beet modes are subject to mode negotiation; tunnel mode is negotiated if the preferred mode is not available.
• pass and drop are used to install shunt policies which explicitly bypass the defined traffic from IPsec processing or drop it, respectively.

StrongSwan default: "tunnel"