When both IP FRR and RSVP shortcut (IGP shortcut) and LFA are enabled in IS-IS or OSPF, and IP FRR is also enabled, the following additional IP FRR are supported.
A prefix that is resolved to a direct primary next hop can be backed up by a tunneled LFA next hop.
A prefix that is resolved to a tunneled primary next hop does not have an LFA next hop. It relies on RSVP FRR for protection.
The LFA SPF is extended to use IGP shortcuts as LFA next hops as described in OSPF and IS-IS support for LFA calculation.