[strongSwan] DPD [lack of] interoperability between strongswan and Cisco IOS

[Martin Willi]

Hi Olivier,

> Strongswan Sends his Vendor ID in Main Mode 1 - IOS sends his vendor ID
> in Main Mode 4 but Strongswan does not seems to recognize it. 

Yes, we currently process vendor ID payloads in the first message only.
Seems that this is insufficient for some implementations.

When I find some time I'll try to fix it and keep the task alive until
MM is complete.

Regards
Martin