Describe MPLS operations (LSR, LDP, label switching, LSP)
7 practice questions under this official exam objective (300-410) — each with the community-verified answer, a full option-by-option explanation and instant feedback.
What Breaks an LSP Between Two PE Routers?
An MPLS LSP between two PE routers is torn down when the LDP adjacency used to exchange label bindings is lost, or when the label bindings no longer m
What Happens to Untagged Outgoing Labels on an MPLS Router?
When an MPLS router's LFIB lists an outgoing label as Untagged (No Label), the LSR removes the entire label stack and forwards the resulting native IP
What Is the MPLS PHP (Penultimate Hop Popping) Label Operation?
MPLS Penultimate Hop Popping (PHP) is the behavior where the second-to-last LSR in an LSP removes the outermost label before forwarding the packet to
Which Tag Sends MPLS L3VPN Packets to the Correct Customer VRF?
In an MPLS Layer 3 VPN, the route target (RT) extended community is the tag that identifies a customer's VPN membership and drives route import into t
What Is the Function of Penultimate Hop Popping (PHP)?
Penultimate hop popping (PHP) is an MPLS mechanism in which the last P router in the LSP pops the transport label so the egress PE receives only the V
MPLS Control Plane Recovery with SSO and NSF
This question tests the mechanism for MPLS forwarding state recovery during a Route Processor (RP) failover. The correct answer identifies that LDP ut
MPLS LSP Tunnel Characteristics
This page explains that an MPLS Label Switched Path (LSP) tunnel is fundamentally unidirectional, distinguishing it from bidirectional protocols like