I'm sorry, I think that I hasn't explained my problem correctly.
The remote users only connect to the internal network few times a day through a VPN. The rest of time, they are offline or connected in their home networks. In the last case, the DLO Agent fails.
This is the scenario:
1. The user plug-in the network cable to the laptop connected to his home network.
2. He start his laptop
3. Appear the CTRL+ALT+SUPR
4. The user enter his username and password.
5. After logon appear an error message informing that access is denied to the backup server.
All users have DHCP configured.
Evidently, when they are on the home network hasn't any visibility with the backup server. Only when they established the vpn network through internet, they can see the backup server.
I think the Desktop Agent has a bug, because in my case, the Desktop Agent should open in offline mode.