Hi Stefano,
I've try your solution that don't run.
I've selected for my external Address (eth1 is the external Interface) :
Use DHCP (send ethernet address as client identifier)
But when the External DHCP Server provide one IP address, the MAC ADDRESS send is the real physical address not the address provide in the script.
content of the ifcfg-eth1 after creation of custom template and signal-event post-upgrade
I don't see any MACADDRESS Param
TYPE=Ethernet
DEVICE=eth1
USERCTL=no
ONBOOT=no
PEERDNS=no
IPV6INIT=no
IPADDR=1.1.1.1
I've try that manually edit it
TYPE=Ethernet
DEVICE=eth1
USERCTL=no
ONBOOT=no
PEERDNS=no
IPV6INIT=no
IPADDR=1.1.1.1
MCADDRESS=AA:BB:CC:DD:EE:FF
The result is the same
if I do (with or without the custom template)
#ifdown eth1
#ifup eth1
after that the network is unreachable

What must I do ? Must I edit the dhcp client of SME ? where is it ?
Thanks a lot
Olivier Beeckmans