My old Imac doesn't recognize new imac during migration process

Hi all, I'm in big trouble with migration process from my old late 2009 20 inches imac to brand new 21,5 inches imac : both using OS 10.9.5.

Whenever I start the migration app on the old imac it starts but on second step it's stuck on searching the new imac. I've tried the ethernet connection and local wi-fi nothing works...

On the other hand the new Imac has found the old imac each and every time.

I'm in quite a rush my old imac is a personal desktop (I wish to bring back home) whereas the new one is my office desktop.

Can anybody help me? Thx.