Exam JN0-363 topic 1 question 12 discussion

bgp—On BGP destinations only. Ingress routes are installed in the inet.3 routing table. bgp-igp—On both BGP and IGP destinations. Ingress routes are installed in the inet.0 routing table. If IGP shortcuts are enabled, the shortcut routes are automatically installed in the inet.0 routing table. bgp-igp-both-ribs—On both BGP and IGP destinations. Ingress routes are installed in the inet.0 and inet.3 routing tables. This option is used to support VPNs. mpls-forwarding—On both BGP and IGP destinations. Use ingress routes for forwarding only, not for routing.

The correct answer is B. mpls-forwarding. This setting ensures that the MPLS routes are used to traverse your network without affecting IGP routes in your route tables. It enables MPLS traffic engineering tunnels on an interface1. This is a key part of configuring MPLS Traffic Engineering (TE), which allows network operators to define how traffic flows through an MPLS core network2. The other options (A, C, and D) are related to BGP and IGP routing, not specifically to MPLS traffic engineering. Please note that actual configuration may vary depending on the specific network devices and software versions you are using. Always refer to the official documentation for your hardware and software for the most accurate information.

B mpls-forwarding. "Unlike the bgp-igp-both-ribs option, the mpls-forwarding option allows you to use the LDP-signaled and RSVP-signaled routes for forwarding, and keep the BGP and IGP routes active for routing purposes so that routing policies can act upon them."

The correct answer is: B. mpls-forwarding Explanation: The mpls-forwarding setting ensures that MPLS routes are used to forward traffic across your MPLS network. It enables traffic to traverse MPLS Label-Switched Paths (LSPs) for traffic engineering purposes. This setting does not interfere with or alter the IGP routes in your routing tables. IGP routes are still used for control plane operations, while MPLS-forwarding directs traffic through the LSPs in the data plane. Why not other options? A. bgp-igp-both-ribs: This setting merges BGP and IGP routes into both the BGP and IGP routing tables, which can affect IGP routes, contrary to the requirements. C. bgp-igp: This setting installs BGP routes into the IGP routing table, which again would impact IGP routes. D. bgp: This applies only to BGP behavior and does not specifically address MPLS traffic engineering.

Per Juniper docs: "To use LSPs for forwarding but exclude them from route selection, include the mpls-forwarding option for the traffic-engineering statement." This would leave BGP and iBGP unaffected.

MPLS forwarding is the answer, it ensures it uses LSPs where applicable

The mpls-forwarding setting allows MPLS to take precedence for forwarding traffic without altering the IGP routes in the routing table.

sould be answer D