So, Everything is ok. not realy as i wanted but it works fine.
First, i wanted to have 2 network cards in SME server, and use it as router for 172.16.0.0 <-> 192.168.40.0.
But finaly, We used our Ciso as router.
Here is what we have done :
CISCO :
On each cisco used (where computers and SME server are plugged), we created a specific VLAN.
We had also to configure Trunk.
On the main cisco, (with Cisco Network Assistant), in device "Proprieties\IP Addresses..." we created an IP address, 192.168.40.254.
This is a "virtual IP" assigned to the main Cisco. don't forget to use the option "route".
FIREWALL :
We also have a Firewall, Endian Firewall, in which we had to add a route :
route add -net 192.168.40.0 netmask 255.255.255.0 gw 172.16.31.252
You can do it permanantly writing this command in :
/etc/rc.d/init.d/rc.local
SME SERVER :
We installed the server as a standalone server (not gateway or private gateway).
the configuration is :
(sorry for translation :p )
Mode : serveronly
Local IP Address / subnet-mask : 192.168.40.1/255.255.255.0
Gateway : 192.168.40.254
Local Networks added : 192.168.40.0/255.255.255.0
Server DHCP : disabled
Then, we had to go in Configuration / workgroup.
Here we have write the "Windows workgroup or domain", the name server, put "YES" at the option "PDC".
In "Security/distant acces", we had to declare the network 172.16.0.0/255.255.224.0, and open the SSH parameters to "LAN and Internet", and "YES" at the 2 options below.
After that, we has done the upgrade (configuration / upgrade), and then, reboot and reconfigure the server (as you have to do after each upgrade).
finaly, you can make your LDAP "nicer" with the good address of your company, create users, add printers, etc...
WINDOWS 7 :
For computers runing with Windows 7, we had to modify the register database (regedit).
Create a reg file with notepad and paste this inside, then execute :
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters]
"DomainCompatibilityMode"=dword:00000001
"DNSNameResolutionRequired"=dword:00000000
COMPUTER NETWORK CONFIGURATION :
IP Static : 192.168.40.X
Mask : 255.255.255.0
Gateway : 192.168.40.254
DNS : 172.16.0.10
And that's all folk
Now, we can add each computer as member of the new domain.
We can ping, see shared folders (with authentification asked by windows), use VNC from external (172.16.x) to internal (192.168.40.x)
I'ld like to have a true "trust relationship", to allow Users of the 172.16.x'AD to go on 192.168.40.X share folders,
But i'll make something more "dusty" who works fine, with net use. (in french we say that "it's a work of pig")
NET Use Z: \\172.16.x.x\share /user:domain\user "password"
I hope this post will help some people, and maybe one day someone will tell us how to make a trust relationship between a domain on Windows 2003 and another on SME.
Zedd