TI-LFA
Fast reroute for segment routing that can protect essentially every destination, regardless of what the network happens to look like.
The classic variant could only protect a destination if some neighbour happened to have a path there that didn't loop back through the broken link. In many real topologies, rings especially, no such neighbour exists, which made protection patchy and hard to reason about — you simply didn't know which destinations were covered. TI-LFA instead uses segment routing's label stack to steer the backup traffic along an explicitly stated path up to the point where normal forwarding takes over, which makes coverage complete. A second advantage is that the backup path is chosen to coincide with the path the network will settle on after recalculating, so traffic isn't disturbed a second time once the IGP has converged.