Cisco 12.4T IOS command reference states following:
The MPLS control plane software is enhanced to make MPLS more scalable and flexible. The MFI,
which manages MPLS data structures used for forwarding, replaces the Label Forwarding Information
Base (LFIB).
Note The MFI and LFIB do not coexist in the same image. Users must use MFI starting with Cisco IOS
Release 12.4(20)T and later releases.
what about guys preparing for CCIEv4 exam, should they be familiar with this MFI.