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Cisco SPRI 300-510 practice questions

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Question 1Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An engineer wants two OSPFv2 routers to form an adjacency across a shared segment. Which pair of parameters must match for the neighbor relationship to reach the FULL state?

  1. Router priority and DR/BDR election results
  2. Interface cost and bandwidth reference value
  3. OSPF process ID and router ID
  4. Hello and dead intervals, area ID, and MTU on the interface Correct answer.

Explanation

Hello/dead timers, area ID, and interface MTU must match for OSPF neighbors to progress past the exchange of database description packets. A mismatch in any of these keeps the adjacency stuck in a state such as INIT or EXSTART rather than FULL.

Question 2Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which OSPF network type treats a multiaccess interface as a broadcast segment and requires a DR/BDR election?

  1. Loopback
  2. Point-to-multipoint
  3. Broadcast Correct answer.
  4. Point-to-point

Explanation

The broadcast network type models a multiaccess segment such as Ethernet and elects a DR and BDR to reduce the number of adjacencies and LSAs. Point-to-point and point-to-multipoint types do not perform DR election.

Question 3Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which IS-IS PDU carries the list of neighbors and the attached prefixes for a Level 2 router and is flooded within the Level 2 area?

  1. Level 1 LAN IIH
  2. Level 1 PSNP
  3. Level 2 CSNP
  4. Level 2 LSP Correct answer.

Explanation

Link State PDUs, or LSPs, carry the router's neighbor information and reachable prefixes, and Level 2 LSPs are flooded throughout the Level 2 topology. Hello PDUs establish adjacencies, while CSNP and PSNP PDUs synchronize and acknowledge the link state database.

Question 4Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

A router running IS-IS has an interface configured with the default IS-IS metric. What is the default narrow metric value applied to that interface?

  1. 1
  2. 100
  3. 10 Correct answer.
  4. 63

Explanation

In narrow metric mode the default IS-IS interface metric is 10, and the maximum value is 63. Wide metrics allow much larger values and are commonly enabled to support traffic engineering and larger topologies.

Question 5Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An engineer redistributes static routes into OSPF on an ASBR. Which OSPF LSA type is generated to advertise these external routes?

  1. Type 7
  2. Type 4
  3. Type 3
  4. Type 5 Correct answer.

Explanation

Type 5 AS-external LSAs are originated by an ASBR to flood external routing information throughout the OSPF domain. Type 4 LSAs describe the ASBR reachability, while Type 7 is used only in NSSA areas.

Question 6Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which mechanism prevents routing loops when routes are redistributed between two routing protocols in both directions?

  1. Configuring a higher administrative distance on both protocols
  2. Enabling split horizon on all participating interfaces
  3. Using route tags and matching them in route maps Correct answer.
  4. Increasing the hello interval on the redistributing interfaces

Explanation

Route tags mark redistributed routes so they can be identified and filtered if they attempt to re-enter the original protocol. This prevents the feedback loop that occurs when two-way redistribution causes routes to be advertised back and forth.

Question 7Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

A network engineer redistributes routes from EIGRP into OSPF and wants the OSPF external cost to reflect the original EIGRP metric. Which configuration accomplishes this?

  1. redistribute eigrp 10 subnets metric-type 1
  2. redistribute eigrp 10 subnets route-map SET-METRIC
  3. redistribute eigrp 10 subnets metric 20 Correct answer.
  4. redistribute eigrp 10 subnets metric 20 metric-type 2

Explanation

When redistributing into OSPF, a seed metric must be specified because OSPF cannot derive a cost from the source protocol's metric. The 'metric 20' keyword sets the external cost to 20, and 'subnets' ensures classless prefixes are included.

Question 8Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An OSPF router receives two external routes for the same prefix: one as a Type 1 external and one as a Type 2 external with equal seed metrics. How does OSPF prefer between them?

  1. It prefers the Type 2 external because the metric is unchanged across the domain
  2. It load-balances between both externals regardless of type
  3. It prefers the path with the lowest total cost, where Type 1 adds internal cost and Type 2 does not Correct answer.
  4. It prefers the Type 1 external because the internal cost is added to the metric

Explanation

For Type 1 externals the internal OSPF cost to the ASBR is added to the external metric, while for Type 2 externals only the external metric is compared. OSPF selects the path with the lower resulting cost, so the type alone does not determine preference.

Question 9Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which IS-IS feature allows a router to advertise a prefix independently of the interface address and is commonly used for loopback addresses?

  1. Passive interface
  2. Prefix attributes Correct answer.
  3. Multi-topology
  4. Wide metric

Explanation

IS-IS advertises connected prefixes based on interface addresses, but prefix attributes allow additional or independent prefixes to be advertised, such as stable loopback addresses. This is useful when the interface address changes but the advertised prefix should remain constant.

Question 10Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

A Level 1-2 IS-IS router receives a Level 1 LSP with the attached bit set from another router. What does this indicate?

  1. The originating router is a Level 2 router with external connectivity Correct answer.
  2. The LSP is corrupted and should be discarded
  3. The originating router is a DIS on the segment
  4. The originating router is a Level 1-only router

Explanation

The attached bit in a Level 1 LSP signals that the originator has connectivity to another area, typically as a Level 2 router. Level 1 routers use this to install a default route toward the nearest attached router.

Question 11Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which OSPF area type allows external routes to be injected as Type 7 LSAs and translated to Type 5 LSAs by the ABR?

  1. Not-so-stubby area Correct answer.
  2. Backbone area
  3. Totally stubby area
  4. Stub area

Explanation

A not-so-stubby area (NSSA) permits an ASBR to inject external routes using Type 7 LSAs, which the ABR translates to Type 5 LSAs for the rest of the domain. Stub and totally stubby areas block external LSAs entirely.

Question 12Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An engineer wants to summarize IS-IS routes from Level 1 into Level 2 on an L1/L2 router. Which command accomplishes this?

  1. area-range 10.0.0.0/8
  2. summary-prefix 10.0.0.0/8 Correct answer.
  3. summary-address 10.0.0.0 255.0.0.0
  4. redistribute connected

Explanation

The 'summary-prefix' command on an L1/L2 router aggregates Level 1 prefixes when advertising them into Level 2. The 'area-range' command is used for inter-area summarization in OSPF, not IS-IS.

Question 13Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which OSPF LSA type is generated by an ABR to advertise a summary route for a network in another area?

  1. Type 1
  2. Type 4
  3. Type 2
  4. Type 3 Correct answer.

Explanation

Type 3 summary LSAs are originated by area border routers to advertise inter-area routes to other areas. Type 1 and Type 2 LSAs describe intra-area topology, while Type 4 identifies the ASBR.

Question 14Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

A router redistributes OSPF routes into IS-IS and IS-IS routes into OSPF. Which two administrative distance values are compared when the same prefix is learned from both protocols on a third router?

  1. OSPF external distance of 110 versus IS-IS distance of 115
  2. OSPF internal distance of 110 versus IS-IS distance of 115 Correct answer.
  3. OSPF external distance of 115 versus IS-IS distance of 110
  4. OSPF internal distance of 115 versus IS-IS distance of 110

Explanation

Cisco routers assign OSPF internal routes an administrative distance of 110 and IS-IS routes 115, so OSPF internal routes are preferred by default. Redistributed OSPF externals use a different distance, so the comparison depends on the source type.

Question 15Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which technique allows a router to run OSPF and IS-IS simultaneously and inject routes between them while avoiding routing loops?

  1. Mutual redistribution with route tags and filtering Correct answer.
  2. Disabling split horizon on all interfaces
  3. Setting identical router IDs on both processes
  4. Passive interfaces on both protocols

Explanation

Mutual redistribution is used to share routes between OSPF and IS-IS, but it requires route tags and filtering to prevent routes from looping back into their original protocol. Without these safeguards, feedback loops can occur.

Question 16Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An engineer configures 'redistribute ospf 1 metric 100' under an EIGRP process. What is the effect of omitting the 'match' keyword in the route map used for redistribution?

  1. Only default routes are redistributed
  2. All routes matching the protocol are redistributed Correct answer.
  3. No routes are redistributed
  4. Only connected routes are redistributed

Explanation

When a route map is referenced without a match clause, the default behavior is to match all routes from the specified source protocol. The route map then applies any set clauses to those routes.

Question 17Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which IS-IS router role is elected on a broadcast segment to generate the pseudonode LSP?

  1. DIS Correct answer.
  2. DR
  3. ASBR
  4. ABR

Explanation

On a broadcast multiaccess segment, IS-IS elects a Designated Intermediate System (DIS) that generates a pseudonode LSP representing the segment. This reduces the number of adjacencies and LSPs flooded on the link.

Question 18Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

A network uses OSPF with a single area and the engineer wants to reduce the size of the link state database on stub routers. Which configuration achieves this with the least disruption?

  1. Configure the area as a totally stubby area
  2. Configure the area as a not-so-stubby area
  3. Configure the area as a stub area Correct answer.
  4. Configure the area as a backbone area

Explanation

A stub area blocks Type 5 external LSAs while still allowing Type 3 summary LSAs, reducing the database size. A totally stubby area blocks both external and inter-area summaries, which is more restrictive than necessary here.

Question 19Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which OSPF feature allows a router to advertise a default route into a stub area without requiring a static default route?

  1. summary-address
  2. redistribute static
  3. default-information originate
  4. area stub default-cost Correct answer.

Explanation

In a stub area, the ABR automatically injects a default route via a Type 3 LSA, and the 'default-cost' option sets its metric. The 'default-information originate' command is used for normal areas and requires a default route to exist unless 'always' is specified.

Question 20Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An engineer observes that an OSPF neighbor remains in the EXSTART state. Which condition most likely explains this?

  1. A mismatch in the interface MTU between the neighbors Correct answer.
  2. A mismatch in the router priority
  3. A mismatch in the interface bandwidth
  4. A mismatch in the OSPF process ID

Explanation

The EXSTART state is where the master/slave relationship is negotiated using database description packets, and an MTU mismatch prevents the exchange from progressing. The adjacency remains stuck until the MTU values are aligned.

Question 21Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which IS-IS PDU is used to request missing or newer LSPs during database synchronization?

  1. CSNP
  2. LSP
  3. IIH
  4. PSNP Correct answer.

Explanation

A Partial Sequence Number PDU (PSNP) is used to acknowledge LSPs and to request missing or newer LSPs from a neighbor. CSNP carries a summary of the complete database, while IIH discovers neighbors.

Question 22Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

A router redistributes a static route into OSPF but the route does not appear in the OSPF database. Which reason is most likely?

  1. The 'subnets' keyword was omitted and the route is a classless prefix Correct answer.
  2. The interface is configured as passive
  3. The static route has a lower administrative distance
  4. The OSPF process ID is incorrect

Explanation

Without the 'subnets' keyword, OSPF only redistributes classful networks and omits classless subnets. Adding 'subnets' ensures the classless prefix is advertised as a Type 5 LSA.

Question 23Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which OSPF LSA type is used by a router to describe its directly connected links and is flooded within a single area?

  1. Type 2
  2. Type 3
  3. Type 5
  4. Type 1 Correct answer.

Explanation

Type 1 router LSAs describe the router's interfaces and neighbors within an area and are flooded to all routers in that area. Type 2 is generated by the DR, Type 3 by ABRs, and Type 5 by ASBRs.

Question 24Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An engineer wants OSPF to prefer a path through a specific neighbor for an external prefix. Which approach is most direct?

  1. Set a lower seed metric on the redistribution of that prefix from that neighbor Correct answer.
  2. Disable DR election on that neighbor
  3. Change the OSPF process ID on that neighbor
  4. Increase the hello interval on that neighbor

Explanation

The seed metric assigned during redistribution determines the external cost, and a lower value makes the path more preferred. Adjusting the metric directly influences OSPF path selection for the redistributed prefix.

Question 25Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which statement best describes the behavior of the IS-IS overload bit?

  1. It signals that the router should not be used as a transit hop for traffic Correct answer.
  2. It forces the router to become a Level 1-only router
  3. It disables the DIS election on all interfaces
  4. It prevents the router from forming any adjacencies

Explanation

Setting the overload bit in the router's LSP tells other routers to avoid using it as a transit node, though directly connected prefixes remain reachable. This is useful during maintenance or when the router's resources are constrained.

Question 26Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which OSPF packet type is used to carry complete link-state advertisements between routers that have already formed an adjacency?

  1. Link State Request
  2. Link State Update Correct answer.
  3. Database Description
  4. Hello

Explanation

Link State Update packets carry one or more complete LSAs and are used to flood new or changed link-state information to adjacent routers. Database Description packets only summarize the LSA headers during database exchange.

Question 27Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

In IS-IS, which PDU type is used by a router to report its own link-state information to all routers within its area?

  1. Partial Sequence Number PDU
  2. Intermediate System Hello PDU
  3. Complete Sequence Number PDU
  4. Link State PDU Correct answer.

Explanation

Link State PDUs carry the actual link-state information and are flooded within a level to synchronize the IS-IS database. Sequence Number PDUs only summarize or request database contents.

Question 28Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which OSPF network type forms a full adjacency between every pair of routers on the segment and elects a DR and BDR?

  1. Broadcast Correct answer.
  2. Non-broadcast
  3. Point-to-multipoint
  4. Point-to-point

Explanation

The broadcast network type treats the segment as a multi-access network, so all routers form full adjacencies and a DR/BDR election reduces LSA flooding. Point-to-point and point-to-multipoint models create adjacencies only between paired neighbors and do not elect a DR.

Question 29Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which OSPF LSA type is originated by an ASBR to describe a destination outside the OSPF routing domain?

  1. Type 2 network LSA
  2. Type 4 ASBR summary LSA
  3. Type 5 AS external LSA Correct answer.
  4. Type 3 summary LSA

Explanation

Type 5 AS external LSAs are generated by an ASBR to advertise routes redistributed into OSPF from other sources. Type 3 and Type 4 LSAs are generated by ABRs to describe inter-area information.

Question 30Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which IS-IS router type can form adjacencies in both Level 1 and Level 2 and is typically used at area boundaries?

  1. Level 1-2 router Correct answer.
  2. Level 0 router
  3. Level 2 router
  4. Level 1 router

Explanation

A Level 1-2 router maintains both a Level 1 and a Level 2 link-state database, allowing it to connect an area to the backbone. Level 1 routers stay within an area and Level 2 routers operate only in the backbone.

Question 31Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which OSPF feature allows an ABR to inject a default route into a totally stubby area automatically?

  1. default-information originate
  2. area range
  3. no-summary on the ABR Correct answer.
  4. redistribute static

Explanation

Configuring 'area X stub no-summary' on the ABR makes the area totally stubby and causes the ABR to advertise a default route while blocking Type 3 summaries. This removes the need for a static default route or redistribution.

Question 32Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which command enables IS-IS for IPv6 on an interface in Cisco IOS?

  1. ip router isis
  2. ipv6 router isis Correct answer.
  3. ipv6 enable isis
  4. isis ipv6 enable

Explanation

The interface-level command 'ipv6 router isis' activates IPv6 IS-IS processing on that interface and associates it with the IS-IS process. The 'ip router isis' command activates IS-IS for IPv4 only.

Question 33Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which OSPF LSA type is flooded only within a single area and describes a router's directly connected links and their states?

  1. Type 5 AS external LSA
  2. Type 7 NSSA external LSA
  3. Type 1 router LSA Correct answer.
  4. Type 3 summary LSA

Explanation

Type 1 router LSAs are generated by every OSPF router and flooded within the originating area only, describing the router's links and their states. Other LSA types have wider scope or different purposes.

Question 34Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An engineer wants to summarize IS-IS Level 1 prefixes into Level 2 on an L1/L2 router. Which command accomplishes this?

  1. redistribute isis level-1 into level-2
  2. summary-address under router isis
  3. summary-address under the interface
  4. area-range under router isis Correct answer.

Explanation

The 'area-range' command under the IS-IS process summarizes Level 1 prefixes and advertises the aggregate into Level 2. The 'summary-address' command under IS-IS summarizes routes redistributed into IS-IS, not Level 1 prefixes.

Question 35Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An engineer configures 'redistribute ospf 1 metric 100' under an EIGRP process. What is the effect of omitting the 'match' keyword?

  1. Only internal OSPF routes are redistributed
  2. All OSPF routes including external and NSSA-external are redistributed Correct answer.
  3. Only external OSPF routes are redistributed
  4. Only default routes are redistributed

Explanation

When the 'match' keyword is omitted under EIGRP redistribution, the default is to match all OSPF route types, including internal, external, and NSSA-external routes. Specifying 'match internal' or 'match external' narrows the selection.

Question 36Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which OSPF LSA type is generated by an ABR to advertise the location of an ASBR to routers in other areas?

  1. Type 3 summary LSA
  2. Type 4 ASBR summary LSA Correct answer.
  3. Type 2 network LSA
  4. Type 5 AS external LSA

Explanation

Type 4 ASBR summary LSAs are generated by ABRs to tell routers in other areas how to reach an ASBR. Type 5 LSAs are originated by the ASBR itself, and Type 3 LSAs describe networks rather than ASBRs.

Question 37Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which IS-IS feature allows a router to advertise a prefix independently of the interface address and is commonly used for summarization?

  1. Multi-topology
  2. Route leaking
  3. Wide metrics
  4. Prefix attributes Correct answer.

Explanation

Prefix attributes allow an IS-IS router to advertise a prefix with specific attributes, such as a different metric or up/down bit, independent of the interface address. This supports summarization and route leaking between levels.

Question 38Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An OSPF router receives two external routes for the same prefix: one as a Type 1 external and one as a Type 2 external with identical metrics. Which route is preferred?

  1. The Type 1 external route Correct answer.
  2. Both routes are installed and load-balanced
  3. The route with the lower forwarding address
  4. The Type 2 external route

Explanation

When external metrics are equal, OSPF prefers the Type 1 external route over the Type 2 route because Type 1 cost includes the internal cost to the ASBR. Type 2 metrics are compared first only when both routes are Type 2.

Question 39Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An engineer redistributes EIGRP routes into OSPF and wants the OSPF external cost to reflect the original EIGRP metric. Which configuration achieves this?

  1. redistribute eigrp 10 metric 20 subnets Correct answer.
  2. redistribute eigrp 10 metric-type 2 route-map SETMETRIC
  3. redistribute eigrp 10 subnets
  4. redistribute eigrp 10 metric-type 1 subnets

Explanation

The 'metric' keyword sets the OSPF seed metric applied to redistributed routes, so specifying 'metric 20' sets the external cost to 20. Without a metric, the default seed metric of 20 is still applied, but explicitly setting it makes the intent clear and avoids relying on defaults.

Question 40Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

A network engineer wants to prevent a specific redistributed prefix from being advertised into OSPF while allowing other redistributed routes. Which tool is most appropriate?

  1. A distribute-list applied inbound on an OSPF interface
  2. A stub area configuration
  3. An area range on the ABR
  4. A route-map with a deny statement applied to the redistribute command Correct answer.

Explanation

A route-map applied to the redistribute command can deny specific prefixes while permitting others, providing granular control over which routes become external LSAs. Area range and distribute-lists affect different aspects of OSPF behavior.

Question 41Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which OSPF router role is elected on a broadcast segment to generate the pseudonode LSA?

  1. ASBR
  2. DR Correct answer.
  3. ABR
  4. BDR

Explanation

The Designated Router generates the Type 2 network LSA, which represents the multi-access segment and its attached routers as a pseudonode. The BDR takes over only if the DR fails, and ASBR/ABR roles relate to external and inter-area functions.

Question 42Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

A router redistributes routes from EIGRP into OSPF with the command 'redistribute eigrp 10 subnets'. Which OSPF LSA type will be generated for those redistributed prefixes?

  1. Type 3 LSA
  2. Type 4 LSA
  3. Type 7 LSA
  4. Type 5 LSA Correct answer.

Explanation

An ASBR redistributing external routes into a normal OSPF area originates Type 5 AS-external LSAs, which are flooded throughout the OSPF domain. Type 7 is used only inside NSSA areas, and Types 3 and 4 are summary LSAs generated by an ABR.

Question 43Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An engineer wants to reduce the number of Type 5 LSAs flooded into a stub area while still allowing external routes to be injected into that area. Which OSPF area type should be configured?

  1. Totally stubby area
  2. Not-so-stubby area (NSSA) Correct answer.
  3. Normal area
  4. Backbone area

Explanation

An NSSA blocks Type 5 LSAs from entering but allows an ASBR inside the area to inject externals as Type 7 LSAs, which the ABR can translate to Type 5. A stub or totally stubby area does not permit external injection at all, and a normal area floods Type 5 throughout.

Question 44Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which IS-IS PDU is used by a router to report its own link-state information to all routers within its area?

  1. Partial sequence number PDU (PSNP)
  2. Complete sequence number PDU (CSNP)
  3. Link-state PDU (LSP) Correct answer.
  4. Hello PDU

Explanation

An LSP carries the router's own link-state information and is flooded within the area to synchronize the link-state database. CSNPs and PSNPs are used to describe and request database contents during synchronization, and Hello PDUs only establish and maintain adjacencies.

Question 45Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An engineer configures 'redistribute ospf 1 metric 100' under an EIGRP process without a route map. What is the result for the redistributed OSPF routes?

  1. All OSPF routes are redistributed with an EIGRP metric of 100. Correct answer.
  2. Only OSPF external routes are redistributed.
  3. Only OSPF intra-area routes are redistributed.
  4. No OSPF routes are redistributed because a route map is required.

Explanation

Without a route map, all OSPF routes matching the process are redistributed into EIGRP, and the metric keyword sets the seed metric for those routes. A route map is optional and is used only to filter or modify which routes are redistributed.

Question 46Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which OSPF router role is elected on a broadcast segment to generate the pseudonode LSA for that segment?

  1. ABR
  2. DR Correct answer.
  3. BDR
  4. ASBR

Explanation

On a broadcast or NBMA segment, the designated router (DR) represents the segment as a pseudonode and originates the Type 2 network LSA describing it. The BDR does not originate this LSA unless it takes over the DR role, and ASBRs and ABRs are defined by redistribution and area boundaries, not by segment election.

Question 47Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

Which IS-IS command summarizes Level 1 prefixes into Level 2 on an L1/L2 router?

  1. redistribute isis level-2
  2. summary-address 10.0.0.0 255.0.0.0 level-1
  3. area-range 10.0.0.0 255.0.0.0
  4. summary-address 10.0.0.0 255.0.0.0 level-2 Correct answer.

Explanation

On an L1/L2 router, the 'summary-address' command with 'level-2' aggregates Level 1 prefixes and advertises the summary into Level 2. The 'area-range' command summarizes inter-area routes on an ABR, and Level 1 summarization uses 'level-1'.

Question 48Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An OSPF router receives two external routes for the same prefix: one as a Type 1 external with a metric of 20, and one as a Type 2 external with a metric of 20. Assuming equal internal cost to both ASBRs, which path is preferred?

  1. The Type 1 external Correct answer.
  2. The Type 2 external
  3. The route with the higher forwarding address
  4. Both are installed and load-balanced

Explanation

When the external metrics are equal, OSPF prefers the Type 1 external over the Type 2 external. Type 1 metrics are treated as more reliable because they include the internal cost to the ASBR, so the Type 1 path wins the comparison.

Question 49Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

An engineer wants to prevent a specific redistributed prefix from being advertised into OSPF while allowing other prefixes to be redistributed. Which approach accomplishes this?

  1. Set the prefix as a Type 2 external.
  2. Apply a distribute-list in to the OSPF process.
  3. Increase the OSPF administrative distance.
  4. Apply a route map with a deny statement under the redistribute command. Correct answer.

Explanation

A route map referenced by the redistribute command can deny the specific prefix while permitting the rest, so only the denied prefix is excluded. A distribute-list in filters routes received from OSPF, and administrative distance affects route selection, not redistribution.

Question 50Routing Protocol Implementation and Optimization (OSPF, IS-IS, and route redistribution)

A network engineer redistributes static routes into OSPF using the command 'redistribute static subnets' under the OSPF process. Without the 'subnets' keyword, which prefixes would have been redistributed into OSPF?

  1. All static routes including subnetted prefixes
  2. Only static routes that match the OSPF router-id subnet
  3. Only classful network prefixes that are not subnetted Correct answer.
  4. Only static routes whose mask is longer than /24

Explanation

By default, OSPF redistribution of external routes only injects classful networks; any prefix with a mask longer than its classful boundary is dropped. The 'subnets' keyword tells the ASBR to also advertise subnetted prefixes as Type 5 LSAs. Without it, only major (classful) networks are redistributed.