300-510 Question #264: Real Exam Question with Answer & Explanation

Question

Refer to the exhibit. All backbone interfaces on the network are in VRF_MPLS and ip rsvp signaling hello is preconfigured on all MPLS routers in the network. After router R2 was upgraded and its configuration restored from backup, LSP signaled via RSVP that the tunnel from R1 had been torn down. The network engineer confirmed IP reachability within the backbone network. Which action must the engineer take to fix the issue?

Options

• AConfigure ip rsvp listener outbound reply 172.16.10.1 vrf VRF_MPLS under the global
• BConfigure ip rsvp signaling hello refresh interval 20 under the interface Gi0/0 configuration on R1.
• CConfigure ip rsvp udp neighbor 172.16.10.1 vrf VRF_MPLS under the global configuration on R2.
• DConfigure ip rsvp udp-multicasts 172.16.10.2 vrf VRF_MPLS under the interface Gi0/0

Explanation

The error log indicates that RSVP communication was lost between R1 and R2, leading to the RSVP Path State Block (PSB) being deleted. The critical line is: RSVP-HELLO: Communication lost with 172.16.10.2 was reset. This suggests an RSVP signaling issue, specifically related to VRF configuration. The command ip rsvp udp neighbor <neighbor-ip> vrf <vrf-name> manually specifies the RSVP neighbor in the given VRF. Since all backbone interfaces are in VRF_MPLS, R2 must explicitly identify R1 as a neighbor in this VRF to establish RSVP communication. Without this configuration, RSVP HELLO messages cannot be sent/received correctly, breaking the tunnel.

No community discussion yet for this question.