JN0-363 Exam Dumps : Service Provider Routing and Switching, Specialist (JNCIS-SP)

Segment routing labels can be distributed by link-state routing protocols such as IS-IS and OSPF, which have been extended to support segment routing capabilities.References:

• Segment Routing Overview, Juniper Networks Documentation
• Understanding Segment Routing with OSPF, Juniper Networks Documentation
• Understanding Segment Routing with IS-IS, Juniper Networks Documentation

With Label Distribution Protocol (LDP), a full mesh of label-switched paths (LSPs) is automatically created between all LDP-enabled routers, and these paths are reflected in the inet.3 table. LDP LSPs are set up when LDP is enabled on interfaces connecting routers in an MPLS network.

References:

• Juniper Networks documentation on LDP: Understanding LDP

In MPLS, multiple paths can be merged if they share the same egress router. In the given scenario, traffic from Network 1 to Network 3 and Network 4 can be engineered to follow the same label-switched path (LSP) within the MPLS network until they reach the last common point before diverging to their respective destinations.

As for R3 performing label operations, in a typical MPLS network, intermediate routers (like R3) perform label swapping. They replace the incoming label with a new label before forwarding the packet along the LSP. A label pop operation is typically performed by the egress router in the case of an ultimate hop pop (UHP), where it removes the MPLS label before delivering the packet to the final destination outside the MPLS domain.

References

• Juniper Networks Technical Documentation on MPLS
• Understanding MPLS Label Operations (Swap, Push, and Pop) - Juniper Networks