JN0-664: Service Provider Professional (JNCIP-SP)

Exhibit.

Referring to the exhibit; the 10.0.0.0/24 EBGP route is received on R5; however, the route is being hidden.

What are two solutions that will solve this problem? (Choose two.)

On R4, create a policy to change the BGP next hop to 172.16.1.1 and apply it to IBGP as an export policy.
On R4, create a policy to change the BGP next hop to itself and apply it to IBGP as an export policy.
On R4, add the internal IBGP interface prefixes to the BGP routing tables.
On R4, add the external EBGP interface's prefix to the IGP routing tables.

Correct answer: B, D

Exhibit

You are attempting to summarize routes from the 203.0.113.128/25 IP block on R8 to AS 64500. You implement the export policy shown in the exhibit and all routes from the routing table stop being advertised.

In this scenario, which two steps would you take to summarize the route in BGP? (Choose two.)

Remove the from protocol bgp command from the export policy.
Add the set protocols bgp family inet unicast add-path command to allow additional routes to the RIB tables. -
Add the set routing-options static route 203.0.113.123/25 discard command.
Replace exact in the export policy with orlonger.

Correct answer: A, C

Exhibit

Referring to the exhibit, PIM-SM is configured on all routers, and Anycast-RP with Anycast-PIM is used for the discovery mechanism on RP1 and RP2. The interface metric values are shown for the OSPF area.

In this scenario, which two statements are correct about which RP is used? (Choose two.)

Source2 will use RP2 and Receiver2 will use RP2 for group 224.2.2.2.
Source2 will use RP1 and Receiver2 will use RP1 for group 224.2.2.2.
Source1 will use RP1 and Receiver1 will use RP1 for group 224.1.1.1.
Source1 will use RP1 and Receiver1 will use RP2 for group 224.1 1 1

Correct answer: A, C

Explanation:

A sham link is a logical link between two PE routers that belong to the same OSPF area but are connected through an L3VPN. A sham link makes the PE routers appear as if they are directly connected, and prevents OSPF from preferring an intra-area back door link over the VPN backbone. A sham link creates an OSPF multihop neighborship between the PE routers using TCP port 646.The PEs exchange Type 1 OSPF LSAs instead of Type 3 OSPF LSAs for the L3VPN routes, which allows OSPF to use the correct metric for route selection1.

After a recent power outage, your manager asks you to investigate ways to automatically reduce the impact caused by suboptimal routing in your OSPF and OSPFv3 network after devices reboot.

Which three configuration statements accomplish this task? (Choose three.)

set protocols ospf3 realm ipv4-unicast overload timeout 900
set protocols ospf overload
set protocols ospf overload timeout 900
set protocols ospf3 overload
set protocols ospf3 overload timeout 900

Correct answer: A, C, E

Explanation:

To reduce the impact of suboptimal routing in OSPF and OSPFv3 after devices reboot, you can use the overload feature to prevent a router from being used as a transit router for a specified period of time. This allows the router to stabilize its routing table before forwarding traffic for other routers. To enable the overload feature, you need to do the following:For OSPF, configure the overload statement under [edit protocols ospf] hierarchy level. You can also specify a timeout value in seconds to indicate how long the router should remain in overload state after it boots up. For example, set protocols ospf overload timeout 900 means that the router will be in overload state for 15 minutes after it boots up.For OSPFv3, configure the overload statement under [edit protocols ospf3] hierarchy level. You can also specify a realm (ipv4-unicast or ipv6-unicast) and a timeout value in seconds to indicate how long the router should remain in overload state after it boots up for each realm. For example, set protocols ospf3 realm ipv4-unicast overload timeout 900 means that the router will be in overload state for 15 minutes after it boots up for IPv4 unicast routing.

To reduce the impact of suboptimal routing in OSPF and OSPFv3 after devices reboot, you can use the overload feature to prevent a router from being used as a transit router for a specified period of time. This allows the router to stabilize its routing table before forwarding traffic for other routers. To enable the overload feature, you need to do the following:

For OSPF, configure the overload statement under [edit protocols ospf] hierarchy level. You can also specify a timeout value in seconds to indicate how long the router should remain in overload state after it boots up. For example, set protocols ospf overload timeout 900 means that the router will be in overload state for 15 minutes after it boots up.

For OSPFv3, configure the overload statement under [edit protocols ospf3] hierarchy level. You can also specify a realm (ipv4-unicast or ipv6-unicast) and a timeout value in seconds to indicate how long the router should remain in overload state after it boots up for each realm. For example, set protocols ospf3 realm ipv4-unicast overload timeout 900 means that the router will be in overload state for 15 minutes after it boots up for IPv4 unicast routing.

Refer to the exhibit.

Click the Exhibit button.

PE-1 and PE-2 are configured with LDP-signaled pseudowires to provide connectivity between CE-1 and CE-2. You notice no connectivity exists between CE-1 and CE-2.

Referring to the exhibit, which two statements describe potential causes for this fault? (Choose two.)

The VC IDs are mismatched.
There is no LSP configured from PE-1 to PE-2.
Interface ge-0/0/0 on PE-1 is down.
There is no LSP configured from PE-2 to PE-1.

Correct answer: A, D

Which two statements describe PIM-SM? (Choose two)

Routers with receivers send join messages to their upstream neighbors.
Routers without receivers must periodically prune themselves from the SPT.
Traffic is initially flooded to all routers and an S,G is maintained for each group
Traffic is only forwarded to routers that request to join the distribution tree.

Correct answer: A, D

Explanation:

PIM sparse mode (PIM-SM) is a multicast routing protocol that uses a pull model to deliver multicast traffic. In PIM-SM, routers with receivers send join messages to their upstream neighbors toward a rendezvous point (RP) or a source-specific tree (SPT). The RP or SPT acts as the root of a shared distribution tree for a multicast group. Traffic is only forwarded to routers that request to join the distribution tree by sending join messages. PIM-SM does not flood traffic to all routers or prune routers without receivers, as PIM dense mode does.

Refer to the exhibit.

Click the Exhibit button.

Referring to the exhibit, you must provide VRF Internet access over a single connection for VPN-A Site 1, which connects to PE-1.

Which two statements are correct in this scenario? (Choose two.)

You must use the RIB group to move a default route, which is learned through BGP, from the inet. o table to the VPN-A. inet. 0 table.
You do not need to use the RIB group to move interface routes from the inet. o table to the VPN-A. inet. 0 table.
You do not need to use the RIB group default route, which is learned through BGP, from the inet. o table to the VPN-A. inet. 0 table.
You must use the RIB group to move interface routes from the inet . 0 table to the VPN-A. inet. 0 table.

Correct answer: A, B

Explanation:

In the provided exhibit, the configuration involves using a RIB (Routing Information Base) group to facilitate internet access for VPN-A Site 1 through PE-1. The goal is to provide VRF Internet access over a single connection.1. **Understanding RIB Groups**:- RIB groups allow for the import and export of routes between different routing tables.- In this scenario, we have two RIBs: `inet.0` (the main routing table) and `VPN-A.inet.0` (the VRF-specific routing table).2. **Statement Analysis**:- **A. You must use the RIB group to move a default route, which is learned through BGP, from the inet.0 table to the VPN-A.inet.0 table.**- Correct. To provide Internet access to VPN-A, the default route (0.0.0.0/0) learned via BGP in the `inet.0` table must be made available in the `VPN-A.inet.0` table. This is done using the RIB group to import the default route.- **B. You do not need to use the RIB group to move interface routes from the inet.0 table to the VPN-A.inet.0 table.**- Correct. Interface routes (connected routes) are typically directly added to both the global and the VRF routing tables without needing a RIB group. These routes are known to the VRF because the interfaces are part of the VRF configuration.- **C. You do not need to use the RIB group default route, which is learned through BGP, from the inet.0 table to the VPN-A.inet.0 table.**- Incorrect. As discussed, the default route needs to be imported into the VRF's routing table using a RIB group to enable Internet access for the VRF.- **D. You must use the RIB group to move interface routes from the inet.0 table to the VPN-A.inet.0 table.**- Incorrect. Interface routes are directly associated with the VRF interfaces and are automatically known to the VRF routing table. There is no need to use a RIB group for these routes.**Conclusion**:The correct answers are:**A. You must use the RIB group to move a default route, which is learned through BGP, from the inet.0 table to the VPN-A.inet.0 table.****B. You do not need to use the RIB group to move interface routes from the inet.0 table to the VPN-A.inet.0 table.****Reference**:- Juniper Networks Documentation on RIB Groups: [RIB Groups Overview](https://www.juniper.net/documentation/en_US/junos/topics/concept/rib-groups-overview.html)- Junos OS VPNs Configuration Guide: [Junos VPNs Configuration](https://www.juniper.net/documentation/en_US/junos/topics/concept/vpns-overview.html)

In the provided exhibit, the configuration involves using a RIB (Routing Information Base) group to facilitate internet access for VPN-A Site 1 through PE-1. The goal is to provide VRF Internet access over a single connection.

1. **Understanding RIB Groups**:

- RIB groups allow for the import and export of routes between different routing tables.

- In this scenario, we have two RIBs: `inet.0` (the main routing table) and `VPN-A.inet.0` (the VRF-specific routing table).

2. **Statement Analysis**:

- **A. You must use the RIB group to move a default route, which is learned through BGP, from the inet.0 table to the VPN-A.inet.0 table.**

- Correct. To provide Internet access to VPN-A, the default route (0.0.0.0/0) learned via BGP in the `inet.0` table must be made available in the `VPN-A.inet.0` table. This is done using the RIB group to import the default route.

- **B. You do not need to use the RIB group to move interface routes from the inet.0 table to the VPN-A.inet.0 table.**

- Correct. Interface routes (connected routes) are typically directly added to both the global and the VRF routing tables without needing a RIB group. These routes are known to the VRF because the interfaces are part of the VRF configuration.

- **C. You do not need to use the RIB group default route, which is learned through BGP, from the inet.0 table to the VPN-A.inet.0 table.**

- Incorrect. As discussed, the default route needs to be imported into the VRF's routing table using a RIB group to enable Internet access for the VRF.

- **D. You must use the RIB group to move interface routes from the inet.0 table to the VPN-A.inet.0 table.**

- Incorrect. Interface routes are directly associated with the VRF interfaces and are automatically known to the VRF routing table. There is no need to use a RIB group for these routes.

**Conclusion**:

The correct answers are:

**A. You must use the RIB group to move a default route, which is learned through BGP, from the inet.0 table to the VPN-A.inet.0 table.**

**B. You do not need to use the RIB group to move interface routes from the inet.0 table to the VPN-A.inet.0 table.**

**Reference**:

- Juniper Networks Documentation on RIB Groups: [RIB Groups Overview](https://www.juniper.net/documentation/en_US/junos/topics/concept/rib-groups-overview.html)

- Junos OS VPNs Configuration Guide: [Junos VPNs Configuration](https://www.juniper.net/documentation/en_US/junos/topics/concept/vpns-overview.html)

Which two statements are correct about reflecting inet-vpn unicast prefixes in BGP route reflection? (Select two.)

Route reflectors add their cluster ID to the AS path when readvertising client routes.
Route reflectors do not change any existing BGP attributes by default when advertising routes.
A BGP peer does not require any configuration changes to become a route reflector client.
Clients add their originator ID when advertising routes to their route reflector

Correct answer: B, C

Explanation:

Route reflection is a BGP feature that allows a router to reflect routes learned from one IBGP peer to another IBGP peer, without requiring a full-mesh IBGP topology. Route reflectors do not change any existing BGP attributes by default when advertising routes, unless explicitly configured to do so. A BGP peer does not require any configuration changes to become a route reflector client, only the route reflector needs to be configured with the client parameter under [edit protocols bgp group group-name neighbor neighbor-address] hierarchy level.

Which statement is true regarding BGP FlowSpec?

It uses a remote triggered black hole to protect a network from a denial-of-service attack.
It uses dynamically created routing policies to protect a network from denial-of-service attacks
It is used to protect a network from denial-of-service attacks dynamically
It verifies that the source IP of the incoming packet has a resolvable route in the routing table

Correct answer: C

In which two ways does OSPF prevent routing loops in multi-area networks? (Choose two.)

All areas are required to connect as a full mesh.
The LFA algorithm prunes all looped paths within an area.
All areas are required to connect to area 0.
The SPF algorithm prunes looped paths within an area.

Correct answer: C, D

Explanation:

OSPF is an interior gateway protocol that uses link-state routing to exchange routing information among routers within a single autonomous system. OSPF prevents routing loops in multi-area networks by using two methods: area hierarchy and SPF algorithm. Area hierarchy is the concept of dividing a large OSPF network into smaller areas that are connected to a backbone area (area 0). This reduces the amount of routing information that each router has to store and process, and also limits the scope of link-state updates within each area.All areas are required to connect to area 0 either directly or through virtual links2. SPF algorithm is the method that OSPF uses to calculate the shortest path to each destination in the network based on link-state information. The SPF algorithm runs on each router and builds a shortest-path tree that represents the topology of the network from the router's perspective.The SPF algorithm prunes looped paths within an area by choosing only one best path for each destination3.