networkd is a small and lean service to configure network interfaces, designed mostly for server use cases in a world with hotplugged and virtualized networking. Its configuration is similar in spirit and abstraction level to ifupdown, but you don't need any extra packages to configure bridges, bonds, vlan etc. It is not very suitable for managing WLANs yet; NetworkManager is still much more appropriate for such Desktop use cases.
There are mainly three setups to have a peer to peer network:
* unprotected ad-hoc interface by configuring the WiFi device
* unprotected ad-hoc interface using wpa_supplicant (Recommended)
* Only with suitable (RSN-IBSS capable) USB dongle:
* protected ad-hoc interface using wpa_supplicant and WPA encryption (best solution if possible)
* ad-hoc interface with additional USB/WiFi dongle for uplink to internet router