Upon a link failure in an RSVP-signaled LSP, the router upstream of the failure (R2) sends a PathTear message upstream to the ingress router (R1), and the router downstream of the failure (R3) sends a ResvTear message downstream to the egress router (R4). These messages signal the failure and initiate tear down of the LSP state in the respective directions.References:

• RSVP-TE Overview, Juniper Networks Documentation
• Understanding RSVP Signal Failures, Juniper Networks Documentation

To prevent a router from participating in the OSPF designated router (DR) and backup designated router (BDR) election process, you set the OSPF priority to 0 on the interfaces of that router. This tells OSPF that the router on those interfaces is not to be considered for election as either DR or BDR, effectively making them DRother routers. The exhibit indicates that this is the desired configuration, and therefore the correct command to issue on the Juniper device would be to set the priority to 0 on the relevant interfaces.

Thenext-hop-self-policypolicy is used to alter the next-hop attribute of BGP routes. When you apply it as an export policy to an external BGP (eBGP) group, it changes the next-hop attribute of the routes being advertised to eBGP neighbors so that the next-hop IP address is the IP address of the router itself. This ensures that the eBGP neighbors use the local router as the next hop to reach these routes.

References

• Juniper Networks Technical Documentation on BGP Policies

https://www.networkfuntimes.com/junos-aggregate-routes-vs-generate-routes-how-to-summarise-on-juniper-routers/

Generated routes are a type of route that can be created to summarize and generate more specific routes within the routing table. Unlike aggregate routes, which summarize existing routes and inherit a next-hop, generated routes do not necessarily have to match an existing route and will have a next-hop of reject by default unless specified otherwise.

References

• Juniper Networks Technical Documentation on Routing Policies and Route Generation

By default, BGP will propagate routes learned from EBGP peers to other IBGP peers. However, due to the BGP split-horizon rule, routes learned from one IBGP peer are notre-advertised to another IBGP peer. This behavior is designed to prevent routing information loops within the same AS.

References:

• Juniper Networks documentation on BGP: BGP Route Propagation and Selection

The exhibit shows theshow vrrp summaryoutput from two routers, with both routers listing the state of their VRRP group asmaster. VRRP allows for multiple routers to share a virtual IP address and a virtual MAC address, but usually, only one router is the master at any given time while others are in backup state. However, in some configurations, VRRP can operate in an active/active mode where multiple routers handle traffic simultaneously for load sharing. Since both routers show the state asmasterand there is no evidence of misconfiguration in the virtual IP addresses or priority, it indicates that VRRP is likely functioning in an active/active setup.

References:

• Juniper documentation on VRRP: Junos OS VRRP Overview

The Segment Routing Global Block (SRGB) defines a range of MPLS labels reserved for segment routing. With an SRGB starting label of 10,000 and an index range of 500, the first usable label is indeed 10,001 because label 10,000 is typically reserved and not usedfor forwarding. The last usable label would be 10,499 because the range includes 500 labels starting from 10,001.

References:

• Juniper Networks documentation on Segment Routing: Segment Routing Overview