client / extension mode ?

Archived from groups: comp.dcom.vpn (More info?)

Hello Group,

I need to know, what exactly these both modes do with the frame.

Cisco sais, in extension mode the remote sites must have routable adresses,
no PAT needed. OK, but in the many examples I have seen there are always
private addresses ... thats confusing for me, what's right ?

Next question is ... today who has so many private addresses at all in a hub-and-spoke topology,
for what is this mode ???

Cisco sais, in client mode, private addresses can be used with PAT.
But in tunnel-mode, I can use client mode without PAT. Right ?
Confusing again ... when do I need PAT in client mode ? Maybe in transport mode ?
But many examples I have seen are with a hub-and-spoke environment, and there
I would choose tunnel-mode anyway. What's right again ?

Thanks in advance,

Matthias