JNCIS-ENT Enterprise Routing and Switching

In Junos OS, which routing table is used for IPv4 unicast routes by default?

• Ainet.0
• Binet.1
• Cinet.2
• Dinet.3

What is the default OSPF hello interval on broadcast and point-to-point networks in Junos?

• A5 seconds
• B10 seconds
• C30 seconds
• D40 seconds

Which STP variant does Junos OS use by default on EX Series switches?

• ASTP (802.1D)
• BRSTP (802.1w)
• CMSTP (802.1s)
• DVSTP

In Junos routing policy, what does the 'then accept' action do when applied to a BGP import policy?

• AIt accepts the route and stops evaluating further policy terms
• BIt accepts the route but continues evaluating subsequent terms
• CIt accepts the route only if all conditions match
• DIt logs the route and continues processing

What is the purpose of Junos Graceful Restart (GR)?

• ATo restart the routing engine without affecting forwarding
• BTo allow a router to maintain forwarding state and neighbor relationships during a routin…
• CTo perform a software upgrade without rebooting
• DTo restart individual routing protocols independently

Which OSPF LSA type describes external routes redistributed into OSPF?

• AType 1 (Router LSA)
• BType 3 (Summary LSA)
• CType 5 (External LSA)
• DType 7 (NSSA External LSA)

In Junos, what command displays the active routing table?

• Ashow route
• Bshow ip route
• Cdisplay routing-table
• Dget route all

What is the default BGP hold time in Junos?

• A60 seconds
• B90 seconds
• C180 seconds
• D240 seconds

In Junos, what is a firewall filter?

• AA stateful firewall feature like SRX security policies
• BA packet classification mechanism applied to interfaces for filtering, rate limiting, pol…
• CA filter applied to management traffic only
• DA mechanism to filter routes in the routing table

What is a trunk port in the context of Junos EX Series switching?

• AA port that connects to a server
• BA port that carries traffic for multiple VLANs using 802.1Q tagging
• CA port that provides uplink to the internet
• DA port configured for LACP aggregation

What is the administrative distance (preference value) for OSPF internal routes in Junos?

• A5
• B10
• C15
• D150

In Junos, what is the purpose of the 'policy-options policy-statement' configuration?

• ATo define security policies for firewall rules
• BTo create routing policies that control route advertisement, acceptance, and manipulation…
• CTo configure QoS policies for traffic shaping
• DTo define user authentication policies

What is the purpose of the Junos 'commit confirmed' command?

• ATo commit changes that require administrator confirmation
• BTo apply configuration changes with an automatic rollback timer — if not confirmed within…
• CTo commit changes to a confirmed backup server
• DTo confirm that the commit was successful

What is the IS-IS NET (Network Entity Title) format used to identify an IS-IS router?

• AAn IP address followed by a subnet mask
• BAn area ID, system ID, and selector byte (e.g., 49.0001.1921.6800.1001.00)
• CA 32-bit router ID similar to OSPF
• DA MAC address with an area prefix

In BGP, what is the difference between eBGP and iBGP?

• AeBGP uses TCP port 179; iBGP uses TCP port 180
• BeBGP peers are in different autonomous systems; iBGP peers are in the same autonomous sys…
• CeBGP supports IPv4 only; iBGP supports both IPv4 and IPv6
• DeBGP is faster than iBGP

What is a VLAN in Junos EX Series switching?

• AA physical LAN segment
• BA logical broadcast domain that segments network traffic at Layer 2, allowing multiple is…
• CA virtual router instance
• DA tunneling protocol for WAN connections

In Junos routing policy, what is a 'community' and how is it used?

• AA group of routers in the same physical location
• BA BGP attribute that tags routes with values for policy matching and filtering across aut…
• CA type of OSPF area
• DA group of interfaces configured for load balancing

What is the purpose of VRRP (Virtual Router Redundancy Protocol) in a Junos network?

• ATo create virtual routers for network segmentation
• BTo provide first-hop redundancy by allowing multiple routers to share a virtual IP addres…
• CTo encrypt traffic between virtual routers
• DTo balance traffic across multiple WAN links

Which OSPF area type blocks all external LSAs (Type 5) from entering the area?

• ABackbone area (Area 0)
• BStub area
• CTotally stubby area
• DNSSA area

In Junos, what is the difference between 'family inet' and 'family ethernet-switching' on an interface?

• A'family inet' is for IPv4; 'family ethernet-switching' is for IPv6
• B'family inet' configures the interface for Layer 3 routing; 'family ethernet-switching' c…
• C'family inet' is for internal networks; 'family ethernet-switching' is for external netwo…
• DThey are interchangeable configurations

What is the first criterion in the Junos BGP path selection process (BGP table path selection)?

• ALowest MED
• BHighest local preference
• CShortest AS path
• DLowest router ID

In Junos, what is the 'prefix-list' used for in routing policy?

• ATo define a list of DNS prefixes
• BTo define a set of IP prefixes that can be matched in routing policy terms for route filt…
• CTo list interface prefixes for DHCP allocation
• DTo configure prefix delegation for IPv6

What does LACP (Link Aggregation Control Protocol) provide in a Junos switching environment?

• ALoad balancing across WAN links
• BDynamic negotiation and management of link aggregation groups (LAGs), bundling multiple p…
• CLoop prevention in spanning tree
• DVLAN trunking between switches

What is the purpose of Junos Nonstop Active Routing (NSR)?

• ATo provide continuous routing even during link failures
• BTo maintain routing protocol sessions during a routing engine switchover by synchronizing…
• CTo ensure routes are never removed from the forwarding table
• DTo provide hitless software upgrades

In OSPF, what is the purpose of the Designated Router (DR) on a broadcast network?

• ATo route all traffic through a single point
• BTo reduce the number of OSPF adjacencies by serving as a central point for LSA exchange o…
• CTo designate which router has priority for forwarding
• DTo provide default routing for the network segment

What is the purpose of BGP route reflection in Junos?

• ATo mirror BGP routes to a monitoring server
• BTo solve the iBGP full-mesh requirement by allowing a route reflector to re-advertise iBG…
• CTo reflect routes back to the originating router for verification
• DTo duplicate BGP sessions for redundancy

In Junos, what is an IRB (Integrated Routing and Bridging) interface?

• AA physical interface that supports both routing and bridging simultaneously
• BA virtual Layer 3 interface associated with a VLAN that enables inter-VLAN routing on a L…
• CAn interface used exclusively for management access
• DA backup interface for redundancy

What is the function of 'route-filter' in a Junos routing policy?

• ATo filter routes based on interface names
• BTo match routes based on prefix and prefix length with optional match types (exact, orlon…
• CTo filter routes based on protocol type only
• DTo rate-limit route updates

What is the purpose of Junos Graceful Routing Engine Switchover (GRES)?

• ATo gracefully shut down a routing engine
• BTo preserve the kernel state and forwarding table during a routing engine switchover on d…
• CTo switch between IPv4 and IPv6 routing
• DTo migrate routing engines between chassis

How does OSPF calculate the cost of an interface in Junos?

• ACost = 10^8 / bandwidth (reference-bandwidth / interface-bandwidth)
• BCost = bandwidth / 10^8
• CCost equals the interface MTU
• DCost is always 1 for all interfaces

In Junos BGP, what is the purpose of the 'multipath' configuration?

• ATo enable multiple paths to the same destination for load balancing across equal-cost BGP…
• BTo configure multiple BGP sessions to the same peer
• CTo enable BGP over multiple VRF instances
• DTo allow multiple AS numbers on the same router

What is a storm control feature in Junos EX Series switching?

• AA feature that monitors weather conditions
• BA mechanism that limits broadcast, multicast, and unknown unicast traffic rates on switch…
• CA protocol for coordinating switch reboots
• DA logging feature for network anomalies

In Junos, what is the difference between 'from protocol ospf' and 'from protocol direct' in a routing policy?

• A'protocol ospf' matches OSPF-learned routes; 'protocol direct' matches directly connected…
• B'protocol ospf' is for IPv4; 'protocol direct' is for IPv6
• C'protocol ospf' matches exported routes; 'protocol direct' matches imported routes
• DThere is no difference

What is the OSPF backbone area and why is it significant?

• AArea 1, used for management traffic
• BArea 0, the central area that all other areas must connect to either directly or via virt…
• CArea 255, reserved for external routes
• DAny area can serve as the backbone

In Junos, what is the purpose of the 'autonomous-system' configuration under routing-options?

• ATo configure the OSPF process ID
• BTo define the BGP Autonomous System Number (ASN) used for BGP peering
• CTo set the IS-IS area ID
• DTo configure the router ID

What is the purpose of the Junos 'protect-re' firewall filter?

• ATo protect routes from being deleted
• BTo protect the routing engine from unauthorized access and DoS attacks by filtering contr…
• CTo protect interface configurations from changes
• DTo protect BGP sessions from hijacking

In IS-IS, what is the difference between Level 1 and Level 2 routing?

• ALevel 1 is for IPv4; Level 2 is for IPv6
• BLevel 1 handles intra-area routing within an IS-IS area; Level 2 handles inter-area (back…
• CLevel 1 is lower priority; Level 2 is higher priority
• DLevel 1 uses SPF; Level 2 uses distance-vector