[strongSwan] Tunnel and Transport mode mismatch

[Tobias Brunner]

Hi Makarand,

> When one side is set to transport and the other set to Tunnel, the child SA is built in Tunnel mode.
> 
> Question: Is this the expected behaviour?

Yes, see RFC 7296, section 1.3.1:

  The USE_TRANSPORT_MODE notification MAY be included in a request
  message that also includes an SA payload requesting a Child SA.  It
  requests that the Child SA use transport mode rather than tunnel mode
  for the SA created.  If the request is accepted, the response MUST
  also include a notification of type USE_TRANSPORT_MODE.  If the
  responder declines the request, the Child SA will be established in
  tunnel mode.

Regards,
Tobias