ldirectord: gate, ipip or masq?

[Keith Edmunds <keith@xxxxxxxxxxxxxxx>]

I've been searching for some information about the various ldirectord
forwarding methods, but I'm struggling to find anything beyond "The
second argument defines the forwarding method, must be gate, ipip or masq".

Could someone point me to more information about them, such what they
are and when one would be preferred over another?

Thanks