SSL, Cookie persistence, and Redirection

It concatenates the 2nd argument to the 1st argument. So, in this case, the result is the virtual server name with the pool name, pool member addr and port following.

As for verifying that the pool member is valid, there is not a specific command for doing that. However, when you set the pool/member, it is validated at that time. So, you would likely want to do something like the following using the Tcl catch command to catch the error if the member is not valid:

 
 if { [catch { use pool $poolname member $poolmbr }] } { 
    log "Invalid pool member $poolmbr - does not exist in pool $poolname" 
    reject 
    return 
 }