could please explain in detials the differnece between RRO and RSVP-hop , and why i used RRO while RSVP-hop indicates the previous ip address which help reservation message to act on
The RRO provides End-to-End Path visibility. The RRO keeps track of the actual path an LSP is traversing. Every node adds to the RRO the address of the interface on which PATH message has been received. This helps to detect possible routing/forwarding loops.i.e, If a node receives a PATH message with one of its local addresses in the RRO, it sends back PathErr message indicating Routing Loop detected.
thanks for your replay , but same role of rsvp-hop object indicate the previous hop ip i can use it to detect if there is any loop in the path message why i used both of them ?
RSVP hop captures only one ip address which is the address of the outgoing interface of the previous hop, each hop re-writes this address with its outgoing interface ip and hence will not have end-to-end visbility like RRO. Capture screen shot from an egress LER (R7) is given below for your reference:
Topology: (22.214.171.124)R1------R2--------R3--------R4--------R5--------R6---------R7 (126.96.36.199)