Rules to redirect based on URL

If the URI path is /User1, /User2 or /User3 (with nothing following), and you are using BIG-IP version 11.4 or higher, you can accomplish this using Local Traffic Policies:

• SOL15085: Overview of the Local Traffic Policies feature

If you are using a version before 11.4, you can use HTTP Classes:

• SOL15085: Overview of the Local Traffic Policies feature

If, instead, the URI path is, e.g., /User1/... (where ... is any arbitrary path) and you want to send everything after the /User1/ part to the server, then you'll need an iRule. Something like this:

when HTTP_REQUEST {
    switch -glob [HTTP::uri] {
        "/User1" -
        "/User1/*" { 
            HTTP::uri [substr [HTTP::uri] 6]
            node 192.168.1.1:80
        }
        
        "/User2" -
        "/User2/*" {
            HTTP::uri [substr [HTTP::uri] 6]
            node 192.168.2.1:80
        }
        
        "/User3" -
        "/User3/*" {
            HTTP::uri [substr [HTTP::uri] 6]
            node 192.168.3.1:80
        }
    }
}

This can be made more efficient, readable and configurable with the use of a datagroup.