CCNA Protocol Independent Routing Questions

Multi-Selectmedium

Which TWO statements are true regarding aggregate routes in Junos OS? (Choose two)

Select 2 answers

A.Aggregate routes have a default preference of 130 in Junos.

B.Aggregate routes have a default preference of 130.

C.An aggregate route automatically forwards traffic even if no contributing routes exist.

D.Aggregate routes require a physical interface to be specified as the next-hop.

E.Aggregate routes can be used to summarize multiple static or dynamic routes into a single advertisement.

AnswersB, E

The default preference for aggregate routes in Junos is indeed 130.

Why this answer

Aggregate routes summarize more-specific routes and do not forward traffic themselves unless paired with discard/reject or resolved via contributing routes.

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Multi-Selecthard

When configuring a routing instance of type 'virtual-router', which THREE characteristics apply? (Choose three)

Select 3 answers

A.It requires MPLS label distribution protocols to function.

B.Interfaces can be assigned directly to the virtual-router instance.

C.It supports dynamic interior routing protocols like OSPF and IS-IS.

D.Route leaking between virtual-router and inet.0 is strictly prohibited by Junos architecture.

E.It maintains independent routing tables separate from inet.0.

AnswersB, C, E

Interfaces are bound directly into the routing-instances hierarchy.

Why this answer

Virtual routers have independent routing tables, support dynamic routing protocols, and operate separately from inet.0.

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MCQmedium

You need to verify that load balancing is functioning properly across your core interfaces and wish to see the specific hash buckets assigned in the forwarding table. Which command should you execute?

A.show system switchover status

B.show forwarding-options hash-results

C.show route forwarding-table destination 192.168.1.1

D.show pfe statistics load-balance

AnswerC

This displays the forwarding table entry for the destination, detailing all active load-balanced next-hops.

Why this answer

The show route forwarding-table destination command displays the next-hops and whether multiple equal-cost paths (load balancing) are active for a destination.

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MCQhard

An administrator configures an aggregate route for 172.16.0.0/16. However, no contributing routes are present in the routing table. What is the default behavior of this aggregate route in Junos OS?

A.It is installed in the routing table with a reject discard next-hop.

B.It installs into the routing table with a next-hop pointing to the local loopback.

C.It floods a default route to all routing instances.

D.It is suppressed and will not be installed in the routing table.

AnswerD

Without contributing routes, an aggregate route is inactive and omitted from the routing table.

Why this answer

An aggregate route in Junos requires at least one contributing (more specific) route to be active in the routing table before it is installed in the routing table and advertised.

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MCQmedium

You need to ensure that traffic entering interface ge-0/0/1 is forced into a specific forwarding routing instance named 'corp-fwd', regardless of the destination IP address in the packet header. Which configuration steps must you perform?

A.Create a forwarding instance, write a firewall filter with 'then routing-instance corp-fwd', and apply the filter as input on ge-0/0/1.

B.Create a virtual-router instance and apply a static default route pointing to ge-0/0/1.

C.Configure a routing policy with 'then export corp-fwd' and apply it under protocols.

D.Enable proxy-ARP on ge-0/0/1 and assign the corp-fwd routing instance to the physical port.

AnswerA

This is the correct three-step workflow for configuring Filter-Based Forwarding in Junos.

Why this answer

Implementing FBF requires creating a forwarding instance, defining a firewall filter that matches the traffic and directs it to that instance, and applying the filter to the ingress interface.

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Multi-Selectmedium

When configuring load balancing on a Juniper Networks router, which TWO actions or components are necessary to achieve functional per-flow load balancing across multiple paths? (Choose two)

Select 2 answers

A.A routing policy containing the 'load-balance' action statement.

B.Application of the export policy under 'set routing-options forwarding-table export'.

C.Setting the routing-instance type to 'forwarding'.

D.Enabling MPLS encapsulation on all core interfaces.

E.A firewall filter applied to every interface running BGP.

AnswersA, B

A policy defining the load-balance action is required.

Why this answer

To achieve load balancing, you must create a routing policy that includes the 'load-balance' action and apply that policy to the forwarding table using 'set routing-options forwarding-table export <policy-name>'.

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MCQeasy

An engineer needs to configure a static IPv4 route on a Juniper Networks MX Series router pointing traffic destined for 192.168.100.0/24 to next-hop 10.0.0.1. Which configuration accomplishes this task?

A.set routing-instances default static route 192.168.100.0/24 next-hop 10.0.0.1

B.set protocols static route 192.168.100.0/24 next-hop 10.0.0.1

C.set interfaces fxp0 unit 0 family inet static-route 192.168.100.0/24 next-hop 10.0.0.1

D.set routing-options static route 192.168.100.0/24 next-hop 10.0.0.1

AnswerD

This is the correct Junos CLI syntax for defining a static IPv4 route.

Why this answer

Static routes in Junos are configured under the routing-options static hierarchy. The correct syntax is set routing-options static route 192.168.100.0/24 next-hop 10.0.0.1.

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MCQhard

You want to configure load balancing across four distinct next-hops. By default, how many paths will Junos install into the forwarding table for ECMP if you configure a load-balancing policy without specifying path limits?

A.Exactly 4 paths

B.Up to 16 paths

C.Up to 64 paths

D.Only 1 path (no load balancing)

AnswerB

Junos supports up to 16 ECMP paths by default.

Why this answer

By default, Junos supports up to 16 equal-cost paths (ECMP) for traffic forwarding, though this can be tuned.

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MCQmedium

An engineer configures a static route pointing to an interface rather than an IP address. What potential issue can occur with interface-based static routes on multi-access Ethernet networks in Junos OS?

A.The packet forwarding engine will crash due to unresolvable MAC addresses.

B.The static route will immediately enter a hidden state due to missing next-hop IP.

C.BGP will automatically re-advertise the interface route into external ASNs.

D.The router will generate an ARP request for every destination IP, potentially exhausting ARP cache.

AnswerD

Interface routes on Ethernet cause the router to treat all destination IPs as directly connected, leading to excessive ARP traffic.

Why this answer

On multi-access networks (like Ethernet), pointing a static route directly to an interface causes the router to ARP for every destination IP address it receives, potentially exhausting ARP tables (Proxy ARP behavior or ARP storm).

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Multi-Selecthard

Which THREE characteristics are true regarding Junos aggregate routes? (Choose three)

Select 3 answers

A.They automatically drop matching traffic by installing a discard next-hop when no contributing routes exist.

B.They require at least one active, more-specific contributing route to become active.

C.They can include component routes from any routing protocol or static configuration.

D.They are assigned a default route preference of 130.

E.They dynamically adjust their prefix length based on the subnet mask of the primary physical interface.

AnswersB, C, D

An aggregate route is inactive without contributing routes.

Why this answer

Aggregate routes summarize multiple routes, are assigned a default preference of 130, and remain inactive unless at least one more-specific contributing route is present in the routing table.

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MCQmedium

You need to configure filter-based forwarding (FBF) to route traffic from a specific subnet (192.168.1.0/24) through an alternate next-hop gateway. Which components are required to implement this successfully?

A.A static route pointing to the alternate gateway with a preference of 1.

B.A firewall filter with a routing-instance action, a custom routing instance, and application of the filter to the ingress interface.

C.An export routing policy with a load-balance action applied globally.

D.A firewall filter with a routing-instance action, a custom routing instance, and application of the filter to the egress interface.

AnswerB

FBF requires matching traffic via a firewall filter on ingress, directing it to a specific routing-instance using the routing-instance action.

Why this answer

Filter-based forwarding requires a firewall filter matching the traffic, a routing instance containing a custom routing table, and applying the filter to the ingress interface.

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Multi-Selectmedium

Which TWO commands can be used to inspect static routes or verify their status in Junos OS? (Choose two)

Select 2 answers

A.show forwarding-table static

B.show static-routes active

C.show route table inet.0 static

D.show route protocol static

E.show interfaces static

AnswersC, D

Displays static routes within the inet.0 routing table.

Why this answer

The show route protocol static and show route table inet.0 static commands are standard ways to inspect static routes.

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Multi-Selecthard

An administrator is troubleshooting an aggregate route that is missing from the routing table. Which THREE conditions could cause an aggregate route to remain inactive? (Choose three)

Select 3 answers

A.All contributing routes have been suppressed or withdrawn.

B.No more-specific (contributing) routes are present in the routing table.

C.BGP split-horizon rule is preventing advertisement.

D.The aggregate route has been explicitly deactivated in the configuration.

E.The router's CPU utilization exceeds 90%.

AnswersA, B, D

If contributing routes disappear, the aggregate route becomes inactive.

Why this answer

Aggregate routes require active contributing routes, lack of suppression, and valid configuration under routing-options.

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MCQhard

When configuring load balancing on a Junos device, you want to include Layer 4 source and destination ports in the hash calculation to achieve finer-grained load distribution. Which configuration statement achieves this under the forwarding-options hierarchy?

A.set forwarding-options hash-key layer-3 layer-4

B.set system services load-balancing ports

C.set routing-options forwarding-table export load-balance-policy

D.set protocols ospf ecmp-hash-ports

AnswerA

Enabling layer-3 and layer-4 hash keys ensures that TCP/UDP ports are factored into the ECMP hashing.

Why this answer

The hash-key options under forwarding-options allow administrators to include Layer 3 and Layer 4 header fields in the load-balancing hash algorithm.

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MCQeasy

You are configuring a virtual router routing instance on a Juniper device to isolate traffic for a specific department. Which routing-instance type should you select?

A.l2vpn

B.forwarding

C.no-forwarding

D.virtual-router

AnswerD

The virtual-router instance type provides a completely separate routing table and supports dynamic routing protocols and static routes.

Why this answer

The virtual-router routing instance type is used for complete isolation of routing tables without requiring interface sharing with MPLS VPNs (unlike VRF).

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MCQhard

You are configuring a qualified next-hop for a static route in Junos to provide redundancy. Which parameter allows you to specify a secondary next-hop with a different preference value?

A.alternate-path

B.qualified-next-hop

C.secondary-route

D.backup-next-hop

AnswerB

The 'qualified-next-hop' statement lets you define alternate next-hops with custom preferences or metrics.

Why this answer

Qualified next-hops allow administrators to assign specific preferences or metrics to individual next-hops of a static route.

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MCQmedium

You are configuring Filter-Based Forwarding (FBF) on an interface. You apply a firewall filter that matches specific source addresses and uses 'then routing-instance' as an action. What must be configured in that target routing instance to ensure return traffic is handled correctly?

A.A default route pointing back to the core gateway within that routing instance's routing table.

B.A static ARP entry for every device on the network.

C.An RSVP LSP bridging the source and destination instances.

D.A BGP peering session with the loopback address.

AnswerA

The FBF routing instance must have a valid path to route the packet; otherwise, it will be dropped as a routing black hole.

Why this answer

Filter-based forwarding only intercepts packets leaving an interface. To ensure traffic can route properly within the target instance and return, routes (such as a default route) must be present in that instance's routing table.

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MCQhard

An engineer has configured a static route to the 192.168.100.0/24 network via 10.0.1.1. However, the route is not installing into the forwarding table because the recursive next-hop cannot be resolved. Which Junos command should the engineer use to verify the resolution status of the recursive next hop?

A.show route resolution

B.show route protocol static detail

C.show route forwarding-table destination 10.0.1.1

D.show system route summary

AnswerB

This command provides detailed path attributes, next-hop states, and resolution metrics for static routes.

Why this answer

The show route protocol static detail command displays detailed information about static routes, including the active next-hop and whether recursive resolution has succeeded.

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Multi-Selectmedium

Which TWO actions occur when a packet matches a static route configured with the 'reject' parameter? (Choose two)

Select 2 answers

A.The packet is silently dropped without any notification.

B.The packet is forwarded to the default gateway.

C.An ICMP destination unreachable message is sent back to the packet source.

D.The route is installed into the forwarding table.

E.The packet is tagged with an MPLS label.

AnswersC, D

Reject returns an ICMP unreachable message.

Why this answer

Reject installs the route into the forwarding table and ensures packets matching it generate an ICMP unreachable message while being dropped.

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MCQhard

An administrator configures filter-based forwarding. The firewall filter uses the action 'then routing-instance custom-vr'. Where must the custom-vr routing instance be defined for the filter to accept this configuration without committing errors?

A.Under the [edit system FBF] hierarchy.

B.Under the [edit interfaces interface-name unit 0 family inet] hierarchy.

C.Under the [edit routing-instances] hierarchy.

D.Under the [edit firewall family inet filter] hierarchy.

AnswerC

Junos requires all custom routing instances to be declared under routing-instances before being referenced in policies or filters.

Why this answer

Any routing instance referenced in a firewall filter action must be explicitly defined under the top-level 'routing-instances' hierarchy.

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Multi-Selectmedium

Which TWO routing instance types support running dynamic interior routing protocols like OSPF and IS-IS within Junos OS? (Choose two)

Select 2 answers

A.virtual-router

B.no-structural-instance

C.Default (inet.0) instance

D.forwarding

E.l2vpn

AnswersA, C

Virtual-router instances support full routing protocol suites.

Why this answer

The default routing instance and the virtual-router routing instance both support running independent dynamic routing protocols.

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MCQeasy

Which routing-instance type is specifically designed to support Layer 3 VPNs (L3VPNs) utilizing BGP as the-peering protocol and MP-BGP for VPN route distribution?

A.virtual-router

B.forwarding

C.VPLS

D.vrf

AnswerD

The vrf instance type is used for L3VPN implementations, supporting route targets and route distinguishers.

Why this answer

The 'vrf' routing instance type is designed for MPLS Layer 3 VPNs, maintaining a distinct routing and forwarding table for each customer.

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MCQhard

An administrator has configured a forwarding-type routing instance to perform filter-based forwarding. Which configuration statement is mandatory under the routing-instances hierarchy to properly define this instance type?

A.set routing-instances dept-fwd routing-options interface ge-0/0/0.0

B.set routing-instances dept-fwd instance-type virtual-router

C.set routing-instances dept-fwd instance-type l3vpn

D.set routing-instances dept-fwd instance-type forwarding

AnswerD

The 'forwarding' instance type is specifically designed for filter-based forwarding (FBF) applications.

Why this answer

A forwarding instance requires the instance-type forwarding statement under the routing-instances definition.

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MCQeasy

What is the primary function of a Junos routing instance of type 'forwarding'?

A.To terminate BGP sessions from multiple external peers

B.To run multiple independent OSPF instances

C.To provide transparent bridging across WAN circuits

D.To support filter-based forwarding without running routing protocols

AnswerD

Forwarding instances allow packets to be routed based on firewall filter actions using separate forwarding tables.

Why this answer

Forwarding instances are lightweight instances that allow filter-based forwarding without running any independent routing protocols or maintaining separate dynamic routing tables.

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Multi-Selectmedium

Which TWO attributes distinguish direct routes from static routes in Junos OS? (Choose two)

Select 2 answers

A.Static routes are created automatically when an interface comes up.

B.Direct routes represent subnets attached to active local interfaces.

C.Direct routes require manual IP address configuration under routing-options.

D.Static routes cannot be used with recursive next-hops.

E.Direct routes have a default preference of 0, whereas static routes have a default preference of 5.

AnswersB, E

Direct routes are automatically generated for connected interface networks.

Why this answer

Direct routes have a preference of 0 and represent local interface subnets, whereas static routes have a default preference of 5 and are manually configured.

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MCQmedium

You are troubleshooting an aggregate route that is not being advertised to BGP peers. You verify that contributing routes are active in the routing table. What command should you use to check if the aggregate route itself is successfully generated and active in the local routing table?

A.show route summary aggregate

B.show bgp aggregate-routes

C.show route protocol aggregate

D.show routing-options aggregate detail

AnswerC

This command shows aggregate routes and verifies whether they are active.

Why this answer

The show route protocol aggregate command displays aggregate routes generated by the router and their active status.

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MCQeasy

Which statement best describes the behavior of a local route in Junos OS?

A.They represent IP addresses assigned directly to the router's local interfaces.

B.They are static routes learned from neighbor routers via CDP.

C.They are manual loopback routes configured by network administrators.

D.They are generated automatically whenever a BGP session drops.

AnswerA

Local routes correspond to the router's own IP addresses and have a preference of 0.

Why this answer

Local routes represent the IP addresses assigned directly to the router's interfaces (such as loopback or physical interface addresses).

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MCQmedium

You need to create a virtual router routing instance to isolate traffic for a specific department. Which routing-instance type should you configure in the Junos configuration?

A.forwarding

B.virtual-router

C.no-structural-instance

D.l2vpn

AnswerB

The virtual-router instance type provides full standalone routing capabilities and separate routing tables.

Why this answer

The 'virtual-router' instance type is used for complete routing isolation where the instance runs its own independent routing protocols and tables, similar to a VRF but without VPN-specific MPLS labels.

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MCQmedium

You are configuring an aggregate route and want to ensure that a discard next-hop is automatically applied when there are no contributing routes, preventing routing loops. Which configuration statement should you use under routing-options?

A.set routing-options static route 10.0.0.0/16 drop

B.set routing-options aggregate route 10.0.0.0/16 passive

C.set routing-options aggregate route 10.0.0.0/16 discard

D.set routing-options aggregate route 10.0.0.0/16 reject

AnswerC

The discard keyword instructs Junos to silently drop packets matching the aggregate route when no contributing components are active.

Why this answer

To secure an aggregate route and silently drop traffic when no more-specific routes exist, the discard option is appended to the aggregate route configuration.

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MCQmedium

You want to ensure that a static route is only installed in the routing table when a specific tracked object or ping test succeeds. Which Junos feature should you pair with the static route?

A.OSPF sham-links

B.Keepalive timers on static routes

C.RPM (Real-time Performance Monitoring) with static route tracking

D.BFD synchronized static routes

AnswerC

RPM probes can track reachability and dynamically pull static routes when connectivity fails.

Why this answer

RPM (Real-time Performance Monitoring) can be integrated with static routes to provide recursive tracking and dynamic route removal if ping probes fail (often called IP SLA equivalent in Junos).

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Multi-Selectmedium

When configuring a static route in Junos, which THREE next-hop options are valid and supported? (Choose three)

Select 3 answers

A.discard

B.reject

C.next-hop <IP-address>

D.metric-out

E.forwarding-class

AnswersA, B, C

The discard option silently drops packets matching the static route.

Why this answer

Junos static routes support specific IP addresses (next-hop), discard/reject options for traffic sinking, and interface-based next-hops for point-to-point or broadcast media.

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MCQhard

An engineer configures multiple static routes to the same destination with different preference values. When all paths are up, how does Junos select which route is active in the routing table?

A.The route configured last in the candidate configuration file becomes active.

B.The route with the lowest preference value is installed as active.

C.The route with the highest metric value is preferred.

D.All routes are installed into the forwarding table for equal-cost multi-path load balancing.

AnswerB

Lower preference values take precedence in Junos path selection.

Why this answer

Junos selects routes based primarily on preference (administrative distance). The route with the lowest preference value is installed as active. If preferences are equal, ECMP may occur depending on configuration.

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Multi-Selectmedium

Which TWO parameters can be modified within a static route configuration to control path selection and backup behavior? (Choose two)

Select 2 answers

A.MED (Multi-Exit Discriminator)

B.Qualified next-hop with custom preference

C.AS-path length

D.Local preference attribute

E.Preference (administrative distance)

AnswersB, E

Qualified next-hop allows specifying backup next-hops with tailored preference values.

Why this answer

Preference and qualified next-hop are static route parameters used to manage path selection and backup preferences.

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MCQhard

An engineer configures an aggregate route for 172.16.0.0/16 on a Junos device. However, the aggregate route is not active in the routing table. What is the primary requirement for an aggregate route to become active?

A.An explicit static route matching the aggregate prefix must be configured.

B.At least one more-specific contributing route must exist in the routing table.

C.A discard policy must be explicitly defined under the aggregate route definition.

D.The aggregate route must be redistributed using BGP or OSPF.

AnswerB

An aggregate route remains inactive unless there is at least one active, more-specific component route matching the aggregate range.

Why this answer

An aggregate route in Junos requires at least one contributing more-specific route present in the routing table to become active.

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MCQhard

You configure an aggregate route and want to control which specific attributes or policies are applied when the aggregate is advertised by BGP. Which routing option is used to assign a specific contributing route tag or policy to an aggregate route?

A.set routing-options aggregate route 10.10.0.0/16 metric 100

B.set routing-instances aggregate-property

C.set protocols bgp aggregate-attribute 10.10.0.0/16

D.set routing-options aggregate route 10.10.0.0/16 policy

AnswerA

Metrics and other parameters can be directly assigned to aggregate routes under routing-options.

Why this answer

Aggregate routes can have specific attributes like preference, metric, and tags assigned using the routing-options aggregate hierarchy.

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MCQhard

An administrator configures a static route with a next-hop that points to an indirect (recursive) address. What condition must be met for this static route to become active in the inet.0 routing table?

A.A more direct route to the next-hop IP must already exist and be active in inet.0.

B.The static route preference must be set lower than 1.

C.The next-hop IP must be directly connected to a physical interface on the local router.

D.BGP multipath must be enabled under routing-options.

AnswerA

Recursive static routes rely on the routing table to resolve the ultimate physical next-hop via an active resolving route.

Why this answer

A recursive static route requires a resolving active route in the routing table (usually learned via an IGP or BGP) that matches the next-hop IP address.

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Multi-Selecthard

When configuring load balancing in Junos OS, which THREE header fields can be included in the hashing algorithm to compute the ECMP path? (Choose three)

Select 3 answers

A.MAC address destination

B.Layer 4 TCP/UDP port numbers

C.Source IP address

D.VLAN ID tagging bits

E.Destination IP address

AnswersB, C, E

Layer 4 ports provide granular flow differentiation when included in hash-key settings.

Why this answer

Junos supports hash-key configuration options that include source IP, destination IP, and Layer 4 source/destination ports.

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MCQeasy

Which command is used to display all configured static routes along with their active/inactive status in Junos?

A.show static routes summary

B.show route protocol static

C.show configuration routing-options static

D.show route table inet.0 static

AnswerB

This command shows all static routes and highlights whether they are active in the routing table.

Why this answer

The show route protocol static command displays routes learned or defined via the static routing protocol.

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Multi-Selecthard

An administrator wants to configure load balancing across multiple static routes. Which THREE configuration elements are required to successfully implement ECMP load balancing for static routes in Junos? (Choose three)

Select 3 answers

A.BFD enabled on all static route next-hops.

B.Export of the load-balancing policy under 'routing-options forwarding-table export'.

C.A routing policy containing the 'then load-balance' action.

D.A virtual-router routing instance wrapper.

E.Multiple static routes to the same destination with equal preference and metric.

AnswersB, C, E

The policy must be exported to the forwarding table to take effect.

Why this answer

ECMP load balancing requires multiple routes with equal preference/metric, a routing policy with 'then load-balance', and export of that policy to the forwarding table.

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Multi-Selectmedium

Which TWO statements accurately describe the behavior and characteristics of a routing instance of type 'forwarding'? (Choose two)

Select 2 answers

A.It automatically generates a default route pointing to the loopback interface.

B.It runs independent OSPF and BGP instances.

C.It requires MP-BGP for VPN label signaling.

D.It is primarily used for filter-based forwarding applications.

E.It maintains a separate forwarding table without running dynamic routing protocols.

AnswersD, E

Forwarding instances are designed specifically for FBF.

Why this answer

Forwarding instances are used for FBF and do not run independent routing protocols or contain separate dynamic routing tables populated by protocols.

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MCQmedium

You need to isolate a set of interfaces into a separate routing table without running dynamic routing protocols inside that table. Which routing instance type should you deploy?

A.virtual-router

B.l2vpn

C.no-structural-instance

D.nat

AnswerA

A virtual-router instance allows static routing and interface isolation without running complex VPN protocols.

Why this answer

A forwarding instance or a virtual-router without protocols can work, but a virtual-router is typically used for routing table isolation, or a forwarding instance for pure FBF. To isolate interfaces with static routing only, a virtual-router instance is ideal.

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MCQmedium

You have configured load balancing across two uplinks using a routing policy. After committing the configuration, you notice that traffic is still exiting only via the primary link. What missing command under forwarding-options is necessary to activate the policy for forwarding table generation?

A.set protocols load-balancing enable

B.set forwarding-options family inet load-balance

C.set routing-options forwarding-table export <policy-name>

D.set interfaces load-balance-ecmp

AnswerC

Exporting a policy to the forwarding table instructs Junos to install multiple next-hops for ECMP.

Why this answer

To apply a load-balancing policy to the forwarding table, you must explicitly declare it under routing-options forwarding-table export.

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MCQeasy

What is the default preference value for a direct route in Junos OS?

A.5

B.20

C.0

D.10

AnswerC

Directly connected routes have a preference of 0.

Why this answer

Direct routes (connected interfaces) have a preference value of 0 in Junos OS, making them the most trusted routes in the routing table.

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MCQhard

An administrator implements filter-based forwarding and applies a firewall filter on the ingress interface. However, traffic matching the filter is dropped rather than routed to the alternate routing instance. Upon investigation, what is the most likely cause of this issue?

A.The ingress interface is configured as a trunk port.

B.The destination IP address does not have a matching route in the alternate routing instance's table.

C.The firewall filter term lacks a 'count' action statement.

D.The routing instance type is set to virtual-router instead of forwarding.

AnswerB

FBF redirects the packet lookup to a specific routing instance's table; if no route matches, the packet is dropped.

Why this answer

If the routing instance specified in the firewall filter action does not have an active route for the destination, the packet is discarded.

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MCQeasy

Which command verifies the interface bindings associated with a specific routing instance named 'engineering'?

A.show route instance engineering

B.show interfaces instance engineering

C.show configuration routing-instances engineering

D.show forwarding-table instance engineering

AnswerA

This command displays operational details including associated interfaces and routing tables for the specified instance.

Why this answer

The show route instance detail or show routing-instance command displays configuration details and interface bindings for specific instances.

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Multi-Selecthard

An administrator is configuring route leaking between a virtual-router routing instance and the default inet.0 table. Which THREE methods or configuration constructs can be used to achieve route leaking in Junos? (Choose three)

Select 3 answers

A.Configuring an aggregate route with a discard next-hop in inet.0.

B.Using logical tunnel (lt) or physical patch cables between instance interfaces.

C.Enabling BGP auto-discovery across all virtual routers without policies.

D.Configuring rib-groups under routing-options to import routes across tables.

E.Using import and export policies between routing instances.

AnswersB, D, E

Physical or logical patch connectivity bridges routing instances at Layer 3.

Why this answer

Route leaking between routing instances can be achieved using rib-groups, import/export policies, or logical tunnel interfaces.

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MCQmedium

You are troubleshooting a load-balancing configuration across multiple equal-cost paths (ECMP) on a Juniper MX Series router. Traffic is hashing persistently onto only one link. Which action should you take to enable per-packet or per-flow load balancing across the ECMP paths?

A.Increase the router's MTU across all core interfaces.

B.Enable BGP multipath under protocols bgp.

C.Configure a routing policy with 'then load-balance' action and apply it to forwarding-options.

D.Configure a static discard route for the loopback interface.

AnswerC

The 'load-balance' action in a routing policy applied via 'export' or 'routing-options forwarding-table' tells Junos to populate the forwarding table with multiple next-hops.

Why this answer

By default, Junos performs destination-based forwarding. To enable load balancing across multiple paths, you must explicitly configure a load-balance policy action with per-packet or per-flow load-balancing options.

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MCQmedium

You need to configure a static route that acts as a discard route, ensuring that any traffic destined for a specific unassigned subnet is silently dropped. Which configuration syntax should you use?

A.set routing-options static route 192.168.50.0/24 drop

B.set routing-options static route 192.168.50.0/24 reject

C.set routing-options static route 192.168.50.0/24 null0

D.set routing-options static route 192.168.50.0/24 discard

AnswerD

The 'discard' action configures a black hole route that drops packets without sending ICMP responses.

Why this answer

Discard static routes are configured by appending the 'discard' keyword to the static route definition.

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Multi-Selectmedium

An engineer is configuring static routes in Junos OS and wants to ensure high availability. Which TWO features can be implemented with static routes to achieve path redundancy? (Choose two)

Select 2 answers

A.Qualified next-hop with varying preference values

B.IGMP snooping on static interfaces

C.OSPF area stubbing

D.Recursive next-hop tracking via RPM or routing table lookups

E.BGP AS-path prepending on static routes

AnswersA, D

Qualified next-hops allow specifying a backup next-hop with a higher preference.

Why this answer

Qualified next-hops and recursive next-hop tracking (or BFD/RPM integration) provide static route redundancy in Junos.

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MCQeasy

Which command allows you to inspect the active forwarding table entries and verify next-hops on a Junos router?

A.show route forwarding-table

B.show interfaces extensive

C.show pfe traffic

D.show routing-engine status

AnswerA

This command shows the exact paths installed in the forwarding table.

Why this answer

The show route forwarding-table command displays the contents of the Packet Forwarding Engine (PFE) routing tables.

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MCQeasy

When configuring a routing instance of type 'virtual-router', what is required to allow communication between the virtual router instance and the default routing instance?

A.Connect a physical cable between two ports on the router (cable-patch).

B.Configure static routes with identical preferences in both instances.

C.Disable firewall filters on all loopback interfaces.

D.Configure leaking routes between instances using rib-groups or routing policies.

AnswerD

Rib-groups or import/export policies are required to share routes across isolated routing instances.

Why this answer

Routing instances are isolated. To share routes between a virtual-router and the default instance, you must explicitly configure route leakage using export and import policies under routing-instances.

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Multi-Selecthard

When configuring advanced load balancing under forwarding-options, which THREE hash-key options are available to administrators in Junos OS? (Choose three)

Select 3 answers

A.mpls-label

B.payload-checksum

C.layer-4

D.layer-3

E.layer-2

AnswersC, D, E

Layer-4 port numbers can be included in hash calculations.

Why this answer

Junos hash-key configuration supports options including layer-2, layer-3, and layer-4 fields.

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MCQeasy

By default, what is the Junos routing protocol preference value assigned to static routes?

A.170

B.10

C.150

D.5

AnswerD

Static routes have a default preference of 5 in Junos OS.

Why this answer

Junos OS assigns a default preference of 5 to static routes, making them more preferred than most dynamic interior routing protocols like OSPF.

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Multi-Selecthard

When configuring Filter-Based Forwarding (FBF), which THREE components are absolutely mandatory for successful operation? (Choose three)

Select 3 answers

A.A firewall filter with 'then routing-instance <name>' action.

B.A routing instance of type 'forwarding' or 'virtual-router'.

C.Application of the firewall filter as input on the ingress interface.

D.BGP multipath enabled across all core interfaces.

E.An RSVP-TE LSP tunnel configured between the routers.

AnswersA, B, C

The filter action dictates where intercepted traffic is sent.

Why this answer

FBF requires a forwarding instance, a firewall filter with a routing-instance action, and the application of that filter to an interface input.

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MCQeasy

What is the key difference between a 'discard' static route and a 'reject' static route in Junos OS?

A.Discard drops packets silently, whereas reject returns an ICMP unreachable message.

B.Reject installs the route into the forwarding table, while discard does not.

C.Discard is used for IPv4 and reject is exclusively used for IPv6.

D.Discard requires an active next-hop interface, while reject does not.

AnswerA

This accurately describes the operational difference between the two Junos static route termination actions.

Why this answer

Discard drops packets silently, while reject drops packets and returns an ICMP destination unreachable message to the sender.

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MCQeasy

Which Junos routing instance type is best suited when you want to run MPLS L3VPNs on a Provider Edge (PE) router?

A.forwarding

B.virtual-router

C.vrf

D.no-structural-instance

AnswerC

The 'vrf' (or vpn) instance type is used for Layer 3 VPNs.

Why this answer

L3VPN routing instances are used on PE routers to maintain customer-specific VRF routing tables and exchange VPN-IPv4 routes via MP-BGP.

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MCQmedium

You have configured multiple static routes to the same destination with different preference values. When does Junos install a static route into the forwarding table (FIB)?

A.Only the static route with the highest preference value is installed into the FIB.

B.Only the static route with the lowest preference value is installed into the FIB.

C.All static routes are installed into the FIB, and traffic is automatically load-balanced across them.

D.All valid static routes are installed into the FIB regardless of preference values.

AnswerB

Junos selects the route with the lowest preference value as the active route and installs it into the FIB.

Why this answer

Only the active route with the lowest preference value among valid routes is installed into the FIB, provided its next-hop is resolvable.

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MCQhard

An administrator is configuring load balancing across multiple equal-cost paths on an MX Series router. Which statement is correct regarding Junos default load-balancing behavior?

A.You must configure a routing policy with the 'load-balance' action and apply it to 'export' under 'routing-options'.

B.Load balancing requires enabling BGP multipath globally under the system hierarchy.

C.Junos automatically load-balances traffic per packet across all equal-cost paths by default without policy configuration.

D.Load balancing is configured directly within the firewall filter configuration using the 'sample' action.

AnswerA

Load balancing requires a policy that sets the load-balance action, applied via routing-options export.

Why this answer

By default, Junos performs destination-based forwarding (destination IP address). To enable per-packet or per-flow load balancing across multiple paths, explicit configuration using a routing policy with the 'load-balance' action is required.

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MCQmedium

You need to configure a static floating route that will only become active if the primary dynamic route learned via OSPF fails. Which configuration parameter must be adjusted to achieve this behavior?

A.as-path prepend

B.local-preference

C.preference

D.metric

AnswerC

Configuring a higher preference value makes the static route less preferred than OSPF, turning it into a floating static route.

Why this answer

Floating static routes rely on a higher preference (administrative distance) than the primary protocol so that they remain inactive until the primary route is removed from the routing table.

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