I have setup the radius authentication on Brocade FC switch, and I am able login with Radius users. however, Radius authentication is not working if the Radius username starts with "_" (underscore) character. When I verified packet capture on Cisco ACS server side, there is no traffic at ACS server side whenever I try with a username with "_" in it (e.g. "_test2") there is no RADIUS authentication request. I suspect FC switch is not able to forward the RADIUS request when username starts with "_". there is "_" in the username.