[ixpmanager] how to move a customer to a different switch?

[Marco d'Itri]

Can somebody explain the correct procedure? My goal is to move 
a customer port to a different switch and keep the same IP address.

If I just define another physical interface for the customer then IXP 
Manager will complain that this is not supported, and indeed weird stuff 
will happen like the 
/v4/provisioner/layer2interfaces/switch-name/foo.json API endpoint 
returning bogus information.

-- 
ciao,
Marco