[strongSwan] dhcp/farp plugins

[Cindy Moore]

I'm trying to understand what is meant by this:

"A new plugin called farp fakes ARP responses for virtual IP addresses
handed out to clients from the IKEv2 daemon charon. The plugin lets a
road-warrior act as a client on the local LAN if it uses a virtual IP
from the responders subnet, e.g. acquired using the DHCP plugin."

So would such a roadwarrior client look like it was operating from its
virtual ip address rather than the vpn gateway?  I'm not clear on
who/what "responder" is.

Thanks,
Cindy