Http_referrer in iRule

[root@ve1023:Active] config  b virtual bar list
virtual bar {
   snat automap
   pool foo
   destination 172.28.19.79:80
   ip protocol 6
   rules myrule
   profiles {
      http {}
      tcp {}
   }
}
[root@ve1023:Active] config  b pool foo list
pool foo {
   monitor all fake
   members 200.200.200.101:80 {}
}
[root@ve1023:Active] config  b rule myrule list
rule myrule {
   when HTTP_REQUEST {
   if {[active_members [LB::server pool]] < 1}{
      HTTP::redirect "http://dns2.com/?origin=http://[HTTP::host][HTTP::uri]"
   }
}
}

[root@ve1023:Active] config  b pool foo|grep -i pool\ member
+-> POOL MEMBER foo/200.200.200.101:80   inactive,down

[root@ve1023:Active] config  curl -I http://dns1.com/whatever
HTTP/1.0 302 Found
Location: http://dns2.com/?origin=http://dns1.com/whatever
Server: BigIP
Connection: Keep-Alive
Content-Length: 0