Is it possible to use Cisco NAT with a Network Bridge in GNS3?

Hi, is it possible to use Cisco NAT with a Network Bridge Microsoft Loopback Adapter? I get the ip 192.168.1.254 from the loopback and my Cisco 2600 router has the ip 192.168.1.1 and my inside network has the ip 192.168.2.254. But I can't ping 192.168.1.254 or 8.8.8.8 from 192.168.2.254.