is it possible to do a salesforce to salesforce connection between a production org and a sandbox org?

when creating a connection from production to sandbox i've tried changing the connection link from "login.salesforce.com" to "test.salesforce.com" but i get a 

"Salesforce to Salesforce: Partner org is not active and no API calls are allowed"

But both sandbox and production are Enterprise orgs with plenty of API calls still left for the 24 hours period. i have used the api to push data into both.