cannot configure management port on catalyst 4948

[cisco.bml]

Hi there, Im trying to configure our cisco catalyst 4948 switch management port. I have gone through this document http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/50sg/configuration/guide/sw_int.html#wp1138747 i have created ip vrf mgmntVrf on the switch. but i couldnt assing it on fastethernet1 interface. Below is the error message i got.

switch(config)#interface fastEthernet ?
  <1-1>  FastEthernet interface number

switch(config)#interface fastEthernet 1
                                   ^
% Invalid input detected at '^' marker.

[tittonandras2]

Hi there, the management port can be used only from software version 12.2(46)SG and later.

See the New Software Features in Release 12.2(46)SG here:

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/release/note/OL_9592.html#wp820800

If you have a software release earlier than 12.2(46)SG, management port can be used only from ROMMON.

Hope this helps.

Best regards,

Andras