In some environments it is impossible to establish a secure VPN connection over an existing Internet connection due to an interim firewall that blocks the ports used by IPsec. To be able to set up an IPsec-secured VPN connection in such a situation, VPN routers support the technology known as IPsec-over-HTTPS.
The first attempt always tries to establish data communications with standard IPsec. If the connection cannot be established (e.g. because IKE port 500 is blocked by a cellular network), then an attempt is then automatically made to establish a connection that encapsulates the IPsec VPN in an additional SSL header (port 443, like https).
Note that IPsec-over-HTTPS technology only works when both ends of the connection support this function and the corresponding options are activated. IPsec-over-HTTPS is available from LCOS 8.0 as well as in LANCOM Advanced VPN Client 2.22 or higher.
