01. PE1 sits in IS-IS domain A and PE9 sits in IS-IS domain B. The two are separate IGP instances joined by BGP, and PE1's traffic engineering database ends at its own domain boundary. The operator needs a low-latency policy from PE1 to PE9 that is recomputed whenever either domain's topology changes.
Which approach meets the requirement, and on what grounds?
a) Configure a flexible algorithm with a delay metric across both domains, because one prefix segment then delivers the constrained path with no policy anywhere.
b) Configure a dynamic candidate path at PE1 with a latency objective, because the head-end recomputes on every topology change and needs no external component to do it.
c) Configure an explicit segment list from PE1 through both domains, because a supplied list needs no traffic engineering database at either end to be imposed.
d) Delegate the computation to a stateful controller fed by the link-state export from both domains, because the head-end cannot compute across a topology it does not hold.
02. Following the duct incident, the operator must guarantee that the backup computed for the R2-R5 link cannot fail with it. Records show that R2-R5 and R3-R6 run through one duct, and that R4-R8 runs through a separate duct on a different street.
Which change makes the computation produce a genuinely diverse backup?
a) Tag the links in each duct with a shared risk group identifier and have the computation exclude the identifiers carried by the protected link.
b) Request a node-disjoint path rather than a link-disjoint one so that no router common to the two paths can carry both of them through one duct.
c) Bind the protected prefix to a flexible algorithm whose definition excludes high-delay links so that the backup is computed over the separate duct.
d) Raise the IGP metric on the links sharing a duct with the protected link so that the computation prefers the link in the separate duct on cost.
03. An operator has replaced an mLDP-based multicast core with Tree SID. During the design review an engineer argues that, since segment routing keeps per-path state only at the head-end, the transit routers in the new design hold no per-tree state at all.
How should that argument be corrected?
a) Transit nodes hold per-tree state that they derive from the root's advertisement, but the SR-PCE supplies the computation they derive it from.
b) Transit nodes hold per-tree state only while traffic is flowing, but the SR-PCE installs each branch on demand as the first packets arrive.
c) Transit nodes still hold per-tree replication state, but it is programmed by the SR-PCE rather than signaled by a tree-building protocol.
d) Transit nodes hold no per-tree state, but the root encodes the whole tree as a segment list that each node reads as the packet passes.
04. Two SRv6 nodes, R3 and R4, are joined by two parallel links of equal capacity and equal IGP cost. An engineer must express a path that leaves R3 over one specific one of those two links, so that a test flow can be pinned to it while the other link remains available for everything else.
Which endpoint behavior should the SID for that hop be bound to?
a) End.DX6, a decapsulating endpoint that forwards to one attached customer adjacency instead of through a table lookup.
b) End.X, a cross-connect that forwards out one named adjacency and is not subject to the shortest-path decision.
c) End, a shortest-path endpoint that forwards toward the node and remains subject to the load-sharing decision at each hop.
d) End.DT6, a decapsulating endpoint that forwards using a lookup in a specific tenant table rather than the global one.
05. R7 and R8 are LDP-only routers that cannot be upgraded during this maintenance cycle. R1, which is SR-capable, has to build a labeled path toward a loopback owned by R8.
What supplies a prefix-SID for R8's loopback?
a) A mapping server advertises a prefix-SID for that loopback on R8's behalf, because a router with no segment routing support cannot advertise a segment for its own prefix.
b) R8's nearest SR-capable neighbor allocates a value from its own local block and advertises it for that loopback, because a proxy segment has to come from a real label allocation.
c) R1 derives the label locally by adding its own global block base to the host portion of that loopback, because a global segment needs no advertisement in order to be computed.
d) The controller learns the loopback through the link-state topology export and installs a prefix-SID into R8's forwarding table, because a non-SR router can still be programmed externally.
06. A wholesale customer's traffic must traverse a named sequence of transit nodes written into a signed interconnect agreement, and an auditor verifies the hop sequence quarterly. The path must not move if the IGP later offers a shorter one, and the operator accepts that a topology change may leave the path down until it is re-supplied.
Which candidate path should the operator configure for this policy?
a) An explicit segment list naming the agreed nodes, since a supplied list is used exactly as written and does not adapt on its own.
b) A dynamic path optimized for the IGP metric with the non-agreed nodes excluded by affinity, since exclusion leaves only the agreed sequence available.
c) An on-demand path instantiated when the customer's colored route arrives, since the head-end then asks the controller for a list matching the agreement.
d) A dynamic path with a hop limit and an affinity constraint set, since the constraints hold the computation to the agreed nodes on every recomputation.
07. During a migration, R4 runs both LDP and segment routing and sits between the migrated region and an LDP-only region. A packet arrives at R4 carrying the segment routing label for a loopback that sits inside the LDP-only region, and the mapping server has advertised a prefix-SID for that loopback.
What must R4 do for the label switched path to remain unbroken to the destination?
a) Swap the incoming segment routing label for the adjacency segment toward the first LDP-only router and let that router impose its own transport label.
b) Push the mapping server's prefix-SID as a further label above the incoming one so that the LDP-only region can resolve the segment for itself.
c) Pop the label and forward the packet natively toward the destination, letting the LDP-only region resolve it from its own routing table.
d) Swap the incoming segment routing label for the LDP label it holds for that prefix and forward the packet into the LDP-only region.
08. In a ring-shaped IS-IS core, remote LFA left several destinations on one router unprotected: no node in the ring qualified as a repair endpoint for them. After the core moved to segment routing with TI-LFA, every destination on that router is protected.
What accounts for the complete coverage?
a) The repairing router no longer needs a targeted session to the repair endpoint, so repair paths that previously failed to come up now establish and the destinations behind them are covered.
b) The repairing router can express an arbitrary repair path as a segment list, reaching a chosen node with a node segment and then forcing the remaining hops with adjacency segments.
c) The repairing router evaluates every directly connected neighbor rather than only the one on the shortest path, so a ring reliably yields at least one neighbor that is loop-free for the destination.
d) The repairing router advertises the protected destinations with a second prefix segment bound to a different algorithm, so a constrained path around the failure exists for every one of them.
09. Provider A runs its own PIM-SM domain behind RP-A, and a source is active in a separate domain behind RP-B. RP-A holds MSDP sessions with two peers, RP-C and RP-D, each reached through a different transit network. RP-B holds one MSDP session, and that session is with RP-D.
Transit for RP-B's address space is asymmetric: the unicast route RP-A holds toward RP-B's own address points out the link facing RP-C. Every MSDP session is established, every PIM neighbor in all three domains is up, and RP-B is originating a Source-Active message for the group, which RP-D forwards on to RP-A. Receivers in Provider A learn no active source for it.
Which statement explains this multi-domain failure?
a) MSDP carries no data stream of its own, so RP-A also needs a multipoint transport built toward RP-B before the remote source can be delivered.
b) The multicast address family is not carried across the transit networks, so RP-A cannot originate a Source-Active message for a source it holds no route toward.
c) A Source-Active message is flooded only within a mesh group, so RP-A never receives an advertisement that was originated outside its own group.
d) The Source-Active message reaches RP-A from a peer that is not on its path back toward RP-B, so the peer-RPF check discards it instead of forwarding it.
10. Inside one PIM-SM domain, a receiver behind R9 has joined an ASM group and its membership is confirmed on R9's local interface. Nothing arrives. The first-hop router at the other end of the network reports that it registered the source successfully. There is no second multicast domain and no MSDP anywhere in this network.
Which two conditions would produce this result?
(Choose two.)
a) R9 is configured with a different rendezvous point address for this group than the routers between it and the source are using.
b) The receiver's host is running a version of IGMP that cannot carry an explicit source list in a membership report.
c) The unicast route toward the rendezvous point on a transit router points out a different interface than the shared tree traffic arrives on.
d) The last-hop router has not yet switched from the shared tree over to the source tree for the group that the receiver requested.
e) The rendezvous point has not yet returned a Register-Stop message to the first-hop designated router that registered this source.
The Cisco 300-510 Certification Sample Questions on this page help you become familiar with the question style and knowledge areas of the Cisco Certified Specialist Service Provider Advanced Routing Implementation (SPRI) exam. Each question is written to reflect the syllabus topics and the level of understanding the certification expects, so you can see how theoretical concepts are tested in practice. Working through them lets you check your understanding, identify topics that need further study, and get comfortable interpreting certification-style questions before you sit the official exam.
