Why am I not able to update my E5810A firmware via Keysight FTP at ftp://ftp.keysight.com/pub/e5810/ ?

The E5810A with firmware revision A.01.06 and below are not able to be update via Keysight FTP. This has been fixed on firmware revision A.01.07 and above. To update the E5810A with current firmware A.01.06 and below to the latest version of the firmware you must use a local ‘ftp’ server. If you wish to update the E5810A with current firmware A.01.07 and above you can use the Keysight ‘ftp’ server. Please see the E5810A online Help for more information on using either ‘ftp’ server method.