Tunneling issues

[zaphod at fsklaw.com]

I have a real poser, and I ccan't solve it.

Currently I have a ipsec vpn tunneling 14 servers through a central server.

Like this:

                       ________________
                       |               |
                       |_______________|
                               |
                               |
                        _________________
                        |                |
                        |________________|
                                |
                                |
                        _________________
                        |                |
                        |________________|

I would like to restructure this so that each server talks to each other
directly, rather than passing everything through a single server.

However, on every other machine I cannot get a second tunnel to come up. 
Not a gre or gif tunnel.  And yet I have 14 on the central machine.

The central machine is FreeBSD5.3, the rest are 6.1 or greater.

I also fear that I won't be able to update the central server, because I
fear not being able to get the tunnels up.

I have been just trying to tunnel.  IPSEC isn't the issue as I'm not
binding an ipsec policy to the tunnel.  I've been googling for days, and
can't find anything on this.  (Can't find anyone creating more than one
tunnel).

Any ideas would be appreciated as I'm totally stumped here.

TIA

Cheers,

Zaphod