Routing Fundamentals

A network engineer is troubleshooting a connectivity issue and wants to see the active routes in the routing table. Which Junos CLI command should they use?

An organization has two ISPs and wants to load-balance traffic equally across both links for all outbound traffic. Which routing configuration approach should be used?

During a routing table lookup, a packet matches both a static route and an OSPF route to the same destination. Which route will be installed in the forwarding table?

Which TWO statements about active routes in the Junos routing table are correct?

Which THREE statements about static routes in Junos are correct?

Which THREE route types are considered protocol-independent in Junos?

Refer to the exhibit. How many static default routes are configured?

Refer to the exhibit. Which route is active for the 192.168.1.0/24 prefix?

You are the network engineer for a mid-sized enterprise with a Juniper MX router running Junos. The router has two uplinks to the internet: one to ISP-A via ge-0/0/0 (10.0.0.1/30) and one to ISP-B via ge-0/0/1 (10.0.0.5/30). You have configured static default routes to both ISPs: one to 10.0.0.2 and one to 10.0.0.6. Both routes have the same preference (default 5) and metric. You enabled ECMP to load-balance outbound traffic. After testing, you notice that all traffic is being sent only to ISP-A, and none to ISP-B. You verify that both interfaces are up and that the next-hop addresses are reachable. You check the routing table and see both routes are active but with different next-hop counts. What is the most likely cause of the traffic not being load-balanced?

Your Juniper router is running OSPF with multiple neighbors. You have a prefix 10.10.10.0/24 that is being learned via OSPF from two different routers: Router A with metric 30 and Router B with metric 20. The OSPF route from Router B is active. You want to ensure that traffic to 10.10.10.0/24 uses the path through Router A instead, even though it has a higher metric. You cannot change the OSPF metric on Router A. Which action should you take?

A router has two routes to the same destination: one with preference 10 and metric 5, and another with preference 15 and metric 3. Which route will be installed in the forwarding table?

Which Junos command displays the route to a specific IP address, including the active route and any backup routes?

A network administrator wants to filter routes from being installed in the routing table based on certain criteria. Which Junos feature should be used?

Which TWO attributes are used by Junos to select the active route among multiple routes to the same destination?

What is the default preference of a direct route in Junos?

A network engineer is troubleshooting a reachability issue between two directly connected routers. Both routers have IP addresses configured on their interfaces and the interfaces are up. Which command would the engineer use to verify the routing table entry for the remote network?

Which THREE statements are true regarding static routes in Junos?

Refer to the exhibit. The router has three static routes configured. Which route will be used to forward a packet destined to 172.16.1.100?

You are managing a small enterprise network with one Juniper router and two switches. The router connects to an ISP via ge-0/0/0 and to the internal network via ge-0/0/1. The internal network uses the 192.168.1.0/24 subnet. You need to configure a default route on the router to send all Internet-bound traffic to the ISP gateway at 203.0.113.1. You also want to ensure that internal hosts can reach the Internet. After configuring the default route, you test connectivity from a host on the internal network to an external website, but the ping fails. You verify that the host has an IP address of 192.168.1.100/24 and a default gateway of 192.168.1.1 (the router's internal interface). On the router, you run 'show route 0.0.0.0/0' and see the default route active. You also run 'ping 203.0.113.1' from the router and it succeeds. However, pinging from the host to the ISP gateway fails. What is the most likely cause?

Which TWO statements are true about static routes in Junos?

Refer to the exhibit. The router has a default static route and a static route to 10.0.0.0/24. An engineer updates the next-hop for the default route from 192.168.1.1 to 192.168.1.2. Which command should the engineer use to verify that the change is active?

Your company operates a dual-homed network with two Juniper MX routers (R1 and R2) each connected to a different ISP. R1 uses BGP to receive a default route from ISP-A (preference 170), and R2 uses BGP to receive a default route from ISP-B (preference 170). Additionally, both routers have a static default route pointing to a local next-hop (192.0.2.1) with preference 5 for backup. R1 and R2 are connected via an internal link (10.0.0.0/30) and run OSPF to exchange internal routes. You notice that traffic from internal hosts is always exiting via R1's ISP-A link, even when R1's BGP session to ISP-A goes down. The OSPF routes are preferred. You want traffic to fail over to R2's ISP-B link when R1 loses its BGP default. Which configuration change should you make?

Order the steps to configure firewall filters (ACLs) in Junos.

Order the steps to reset the root password on a Junos device via the console.

Match each Junos routing protocol to its primary characteristic.

Match each Junos configuration hierarchy to its function.

A network administrator configures a static route on a Juniper device: `set routing-options static route 192.168.100.0/24 next-hop 10.0.0.1`. The administrator verifies the route is present in the routing table but notices it is not active. What is the most likely cause?

An engineer observes that traffic destined to 203.0.113.0/24 is being load-balanced across two equal-cost paths via OSPF. The engineer wants to ensure that all traffic for this prefix uses only one path unless the primary path fails. Which configuration change should be made?

A router has two ISIS adjacencies to the same router, both with equal metrics. The router installs both routes in the routing table and performs load balancing. The network team wants to verify that both next-hops are being used for a particular destination. Which command provides this information?

A Juniper device receives several routes to the same destination prefix from different routing protocols. Which parameter is used first to select the active route?

A network administrator configures the following: `set routing-options static route 0.0.0.0/0 next-hop 192.168.1.1`. After committing, the administrator notices that the default route is not active. What could be the reason?

A static route with a next-hop of 10.0.0.1 is configured, but the route is not appearing in the active routing table. The output of `show route 10.0.0.1` shows that 10.0.0.1 is reachable via an OSPF route with preference 10. What is the most likely reason the static route is not active?

An engineer wants to configure a static route that will be used only if the primary route (learned via OSPF) becomes unavailable. Which feature should be used?

A Juniper MX router is configured with multiple routing instances. In which scenario would an interface be automatically placed in a routing instance?

A network engineer is troubleshooting a BGP routing issue. The router receives a route to 172.16.0.0/16 from two BGP peers with different local preferences. The route from peer A has local preference 200, and from peer B has local preference 100. The router selects the route from peer A. What is the next step in BGP path selection if the local preferences were equal?

Which two statements are true about static routes on Juniper devices? (Choose two.)

Which two factors determine whether a route is active for a given destination when multiple routes from different protocols exist? (Choose two.)

A route is present in the routing table but is not active. Which three conditions could explain this? (Choose three.)

Refer to the exhibit. Why is the static route not active?

Refer to the exhibit. Why is the static route not active?

Refer to the exhibit. What does the 'user' type indicate about the route?

A network administrator configures a default route using 'set routing-options static route 0.0.0.0/0 next-hop 10.0.0.1 preference 10' and later enables OSPF which also advertises a default route with default preference 150. Which route becomes active in the routing table?

An engineer configures a static route to 192.168.0.0/16 with next-hop 172.16.1.1. The router has a directly connected route for 172.16.1.0/30 via interface ge-0/0/0.1. However, the static route appears as 'hidden' in the routing table. What is the most likely cause?

Two routers running IBGP with full mesh have a routing loop for prefix 10.1.1.0/24. Both routers have an IBGP route (preference 170) for the prefix with next-hop 10.2.2.2, and an OSPF route (preference 10) for the same prefix. The OSPF next-hop on each router points to the other router's loopback interface. Which action should be taken to stop the loop while preserving BGP route advertisement?

Which JunOS command displays the active route for a specific destination along with the outgoing interface?

A network has two equal-cost OSPF paths to 192.168.1.0/24. The engineer wants to enable per-flow load balancing. Which configuration element is required?

An enterprise uses OSPF across multiple areas. To reduce routing table size in the backbone area, the engineer wants to advertise a single summary route for all subnets in area 2. Which configuration is appropriate?

What is the default preference value of a directly connected (direct) route in JunOS?

An administrator suspects that routing protocol updates are being sent to an incorrect next-hop. Which command can be used to capture and analyze the routing protocol packets on an interface?

A route learned via BGP appears as 'hidden' in the routing table. Which condition is most likely the cause?

Which TWO statements are true about the default route in JunOS? (Choose two.)

Which THREE conditions must be met for a route to be considered active in the JunOS routing table? (Choose three.)

Which TWO factors are directly used when comparing route preferences in JunOS? (Choose two.)

Refer to the exhibit. Why is the route for 192.168.1.0/24 hidden?

Refer to the exhibit. How many active routes exist for 10.1.1.0/24?

Refer to the exhibit. The route for 192.168.0.0/16 is hidden. What is the most likely reason?

A network engineer configures a static route to a remote network. They want the route to be automatically removed from the routing table if the directly connected interface used to reach the next hop fails. Which configuration approach should be used?

A network administrator is troubleshooting a missing route in the routing table. The route is learned via OSPF, and the OSPF neighbor adjacency is up. Which command would help determine if OSPF received the route?

A router has multiple equal-cost paths to the same destination. Which statement describes how Junos load balances traffic across these paths?

A network engineer configures a static route to 10.0.0.0/8 with a preference of 20. An OSPF internal route to 10.0.0.0/8 has a default preference of 10. Which route will be active in the routing table?

A network is experiencing intermittent routing loops. The engineer discovers that routes are being redistributed from OSPF into BGP and then from BGP back into OSPF on different routers. What is the most effective way to prevent this?

A static route is configured with next-hop 10.0.0.1, but the route does not appear in the routing table. The interface ge-0/0/0 has IP 192.168.1.2/24 and is up. What is the most likely reason?

An engineer is configuring multiple static routes to the same destination for redundancy. The primary link uses 192.168.1.1 and the backup uses 192.168.2.1. They want the backup to be used only when the primary next-hop is unreachable. Which configuration is correct?

A router is running OSPF and iBGP. Both protocols learn a route to 10.0.0.0/8. The OSPF route is in the routing table with a preference of 10, and the iBGP route has a preference of 170. Which event would cause the iBGP route to become active?

A network must forward traffic to 10.1.1.0/24 through a specific next-hop 192.168.1.1, even if a dynamic route with a lower preference is available. Which configuration will achieve this?

Which TWO statements about route preferences in Junos are correct?

Which THREE factors are considered when Junos selects the active route among multiple routes to the same destination?

Which TWO configuration statements are valid for defining a static route on a Junos device?

Refer to the exhibit. How many next hops are installed for the 10.1.1.0/24 route?

Refer to the exhibit. If the primary next-hop (192.168.1.1) becomes unreachable, what will happen to the route?

Refer to the exhibit. What is the most likely cause of this BGP route being hidden?

An administrator configures a static route to 192.168.2.0/24 with next-hop 10.0.0.1. The route does not appear in the routing table. What is the most likely cause?

A router has an OSPF route to 10.10.10.0/24 with preference 10 and a static route to the same prefix with preference 5. Which route is active in the routing table?

An engineer configures two static routes to 172.16.0.0/16 with next-hops 10.0.1.1 and 10.0.2.1, both with the same preference and same metric. How does Junos handle traffic to this prefix?

An administrator executes 'show route 192.168.1.0/24' and sees no output, but the route is configured. Which command should be used to display the reason the route is not active?

You configure an aggregate route for 172.16.0.0/16. What must exist for this aggregate to be active in the routing table?

A static route to 10.0.0.0/8 has next-hop 192.168.1.1. The route is not installed in the routing table. Which condition must be met for the route to become active?

A router receives two OSPF routes for 10.10.10.0/24: one intra-area with preference 10 and metric 1, and one external type 2 with preference 150 and metric 20. Which route is selected as active?

A router has a directly connected route to 10.10.10.0/24 on interface ge-0/0/0.0, a static route to the same prefix with next-hop 192.168.1.1, and an OSPF route to the same prefix. Which route is active in the routing table?

An administrator wants to drop traffic destined to the 10.10.10.0/24 network without sending an ICMP unreachable message back to the source. Which static route option should be used?

Which two factors does Junos use to select the best route when multiple routes to the same prefix exist? (Choose two.)

Which two static route options result in traffic being dropped at the router? (Choose two.)

Which three characteristics are true for OSPF? (Choose three.)

Refer to the exhibit. Why is the route via 10.0.0.1 selected as the active route?

A network engineer is managing a hub-and-spoke OSPF network for a retail company. The hub router (hub01) is at the data center with a loopback address 10.99.99.99. The spoke router (spoke01) is at a branch office and connects to hub01 via two links: a primary T1 link on interface ge-0/0/0.0 and a backup LTE link on interface lte-0/0/0.0. Both links are in area 0. Recently, the spoke router began sending traffic to the hub's loopback over the LTE link instead of the T1 link, causing higher latency and data charges. The engineer checks the routing table on spoke01 and sees that the route to 10.99.99.99/32 has two equal-cost next-hops: one via ge-0/0/0.0 and one via lte-0/0/0.0. The engineer wants to ensure that only the T1 link is used under normal conditions, with the LTE link as a backup. Which action should the engineer take to achieve this?

A service provider operates a Juniper MX router that receives a default route from two different ISPs via EBGP. Both ISPs advertise 0.0.0.0/0 with the same local preference (100), same AS path length, and same metric. The network administrator wants to load balance outgoing traffic across both ISPs for redundancy and bandwidth utilization. After applying the configuration, the administrator checks the routing table and sees that only one default route is active, the one from ISP-A. The other route from ISP-B is present but not active. The administrator verifies that both routes have the same preference (170) and same BGP attributes. The ISP links are different: ISP-A is connected via interface ge-0/0/0.0 with next-hop 10.1.1.2, and ISP-B via interface ge-0/0/1.0 with next-hop 10.2.2.2. What is the most likely reason that both routes are not active and load-balanced?

A network engineer is troubleshooting a connectivity issue between two directly connected routers, R1 and R2. Both routers have IP addresses configured on their respective interfaces, and the interfaces are up. However, 'ping 192.168.1.2 source 192.168.1.1' from R1 fails. The engineer checks the routing table on R1 and sees a static route to 0.0.0.0/0 via a different next-hop, but no route for the 192.168.1.0/24 network. What is the most likely cause?

Which TWO statements about static routes in Junos OS are correct? (Choose two.)

Which THREE factors influence the selection of the active route in the Junos routing table when multiple routes exist for the same destination? (Choose three.)

You are managing a small branch office with a Juniper SRX firewall that connects to the internet via a single ISP. The internal network uses 192.168.1.0/24. You need to configure a default route so that all internet-bound traffic goes to the ISP's next-hop 203.0.113.1. The SRX has two interfaces: ge-0/0/0 (untrust) with IP 203.0.113.2/30 and ge-0/0/1 (trust) with IP 192.168.1.1/24. You add the following configuration: 'set routing-options static route 0.0.0.0/0 next-hop 203.0.113.1'. After committing, devices on the trust network can ping the internet (e.g., 8.8.8.8) successfully. However, users report that they cannot access a specific public website hosted at 198.51.100.10. You verify that the SRX can reach that IP via ping and traceroute. What is the most likely cause of this issue?

Your company recently acquired a small office that uses a Juniper MX router to connect to two ISPs for redundancy. The router has two uplinks: xe-0/0/0 to ISP-A (next-hop 10.0.0.1) and xe-0/0/1 to ISP-B (next-hop 10.0.1.1). The router receives a full BGP table from both ISPs. You want to prefer ISP-A for most traffic, but use ISP-B as a backup. You have configured BGP with local-preference 200 on routes from ISP-A and local-preference 100 on routes from ISP-B. After committing, you check the routing table and see that for some destinations, the route from ISP-B is active despite having lower local-preference. What is the most likely reason?

A service provider is migrating from a legacy core network to Juniper MX series routers. In the new design, each MX router runs OSPF as the IGP with a single backbone area 0 and multiple non-backbone areas for customer aggregation. The network uses route summarization at area border routers (ABRs) to reduce routing table size. During testing, engineers notice that some customer prefixes from area 1 are not being propagated to the backbone area, even though the ABR has a valid route to those prefixes and has been configured with 'area 1 range 192.168.0.0/16'. The ABR is an MX240 running Junos 21.4R1. The 'show ospf route' command on the ABR shows the individual customer prefixes (e.g., 192.168.1.0/24) in the OSPF routing table, but the summary route is not present in the backbone area's database. Additionally, 'show ospf database summary' on a backbone router does not show the summary LSA for 192.168.0.0/16. What is the most likely cause?

You are configuring a Juniper MX router to act as a BGP route reflector for your ISP network. The router has several iBGP peers, including clients and non-clients. You have configured the route-reflector-cluster-id and set the clients. After the configuration, you notice that some prefixes are not being reflected to a specific client router. The client has a valid BGP session to the route reflector and can see other prefixes. You check the BGP routing table on the route reflector and see that the missing prefixes are present but have the 'non-routable' flag. The route reflector's BGP table shows the prefix with a next-hop that is reachable via an IGP route. What is the most likely cause?

You are a network engineer at a company that uses a pair of Juniper EX4300 switches in a virtual chassis (VC) configuration for the campus core. The VC is running OSPF with a single area and has multiple uplinks to an upstream router. The router is advertising a default route via OSPF. You want all inter-vlan traffic within the VC to be switched, but internet-bound traffic should be routed via the default route. You notice that some VLANs are not able to reach the internet while others can. All VLANs have a default gateway on the VC, which is the same IP (the VC's management IP). Users in the failing VLANs can ping the default gateway but cannot ping the upstream router's interface IP. What is the most likely cause?

Which two statements about static routes in Junos OS are correct?

Refer to the exhibit. A network administrator configured a static route to 10.0.0.0/24 with next-hop 192.168.1.1. The route is not appearing in the active routing table. What is the most likely reason?

You are a network engineer for a company that uses two Juniper routers, R1 and R2, connected via an Ethernet link. R1 and R2 are running OSPF in the same area, and R2 also has an eBGP session with a service provider to reach the internet. On R1, you have configured a static route to the subnet 172.16.10.0/24 with a next-hop of 192.168.1.2, which is the IP address of R2's interface facing R1. You have verified that the static route is configured correctly in the configuration, but traffic from R1 to 172.16.10.0/24 is not being forwarded. You check the routing table on R1 and see that the static route is present but marked as 'hidden'. You also notice that R1 has an OSPF-learned route to 192.168.1.0/30 (the link between R1 and R2) with a cost of 1. What is the most likely reason for the hidden static route?