Think you would have a problem with the ethernet ports. Old router termed as interface ethernet0/0...new router probably will be interface fastethernet0/0 so tftp would probably no work. Save as a text file then you can edit, cut, and paste into new router. Also make sure your new router has the appropriate feature set comparable to the existing router. Would have problems if new router had basic feature set and old router had advanced feature set and was configured to use them. Why not just put a NM-1E into the module slot for an extra ethernet port....save lots of dough.