If a RADIUS server is case-sensitive and it expects the user name and password only in lowercase, then MAC Authentication will fail due to the case mismatch, since whenever a MAC address is used as user name and password, by default the MAC address is sent only in uppercase.
ExtremeXOS 30.3 provides an option to send the Network Login (NetLogin) MAC Authentication MAC address in either upper or lower case for the user name or password.
To change the MAC case, use the following command:
configure netlogin mac username case (lower | upper}