HP ProCurve Switch 6120G/XG Manual page 208

[key < key-string >]
Optional. Specifies an encryption key for use during
accounting or authentication sessions with the speci-
fied server. This key must match the encryption key
used on the RADIUS server. Use this command only if
the specified server requires a different encryption key
than configured for the global encryption key.
Note: When you save the config file using Xmodem
or TFTP, the key information is not saved in the
file. This causes Radius authentication to fail
when the config file is loaded back onto the switch.
(For a more complete description of the radius-server command and its
options, turn to page 5-14.)
RADIUS Authentication, Authorization, and Accounting
Configuring RADIUS Accounting
5-41