IGP shortcuts enable traffic to get forwarded along traffic engineered paths computed by RSVP using a modified SPF

IS-IS 4.25.0FX LDP RSVP IGP Shortcut

LSPs formed by LDP normally follow IGP routing. The LDP speaker selects the downstream LSR for a particular prefix as

LDP RSVP Tunnel 4.25.0FX LDP RSVP Encapsulation