yum authenticaiton problem

hello everyone:     I'm a newbie.Recently I began to set up an update system for my lab,because our servers are all centos,I chose the yum.     I set up a main server as the yum server,some remote servers were connceted to it to update rpm packages.     I wrote repo file on remoteservers like this:     baseurl=ftp://username:password@address/path     but I found a problem,and till now ,I can't solve it.So I need your help.      The question is this:      How can I hide the username and password or password only,or make the url invisible,in order to make my main server secure.      Your help will be grateful,and forgive my poor English.      thank you  ----Rick Chang

_______________________________________________
Yum mailing list
[email protected]
https://lists.dulug.duke.edu/mailman/listinfo/yum