iRule to redirect based on client username

well source IP or usernames are just arbitrary fields, It is very trivial to change the data source you are using. It could depend where you are getting the username from, as that could take all sorts of forms and you've not said if this is an HTTP header, cookie value etc.

 

 

In the simple exampels given here, just change the variable you are using for the input of the switch http://devcentral.f5.com/Community/GroupDetails/tabid/1082223/asg/50/aft/21726/showtab/groupforums/Default.aspx