Top Tips Of Up To The Minute JN0-664 Free Practice Exam

NEW QUESTION 1
Exhibit

Referring to the exhibit, which three statements are correct about route 10 0 0.0/16 when using the default BGP advertisement rules'? (Choose three.)

• A. R1 will prepend AS 65531 when advertising 10 0.0 0/16 to R2.
• B. R1 will advertise 10.0.0.0/16 to R2 with 192 168 1 1 as the next hop.
• C. R2 will advertise 10.0.0.0/16 to R3 with 192.168.1 1 as the next hop
• D. R4 will advertise 10 0.0 0/16 to R6 with 172.16 1 1 as the next hop
• E. R2 will advertise 10.0.0.0/16 to R4 with 172.16.1.1 as the next hop

Answer: BDE

Explanation:
The problem in this scenario is that R1 and R8 are not receiving each other’s routes because of private AS numbers in the AS path. Private AS numbers are not globally unique and are not advertised to external BGP peers. To solve this problem, you need to do the following:
✑ Configure loops on routers in AS 65412 and advertise-peer-as on routers in AS 64498. This allows R5 and R6 to advertise their own AS number (65412) instead of their peer’s AS number (64498) when sending updates to R7 and R8. This prevents a loop detection issue that would cause R7 and R8 to reject the routes from R5 and R62.
✑ Configure remove-private on advertisements from AS 64497 toward AS 64498 and from AS 64500 toward AS 64499. This removes any private AS numbers from the AS path before sending updates to external BGP peers. This allows R2 and R3 to receive the routes from R1 and R4, respectively3.

NEW QUESTION 2
Your organization manages a Layer 3 VPN for multiple customers To support advanced route than one BGP community on advertised VPN routes to remote PE routers.
Which routing-instance configuration parameter would support this requirement?

• A. vrf-export
• B. vrf-import
• C. vrf-target export
• D. vrf-target import

Answer: C

Explanation:
The vrf-target export parameter is used to specify one or more BGP extended community attributes that are attached to VPN routes when they are exported from a VRF routing instance to remote PE routers. This parameter allows you to control which VPN routes are accepted by remote PE routers based on their import policies. You can specify more than one vrf-target export value for a VRF routing instance to support advanced route filtering or route leaking scenarios.

NEW QUESTION 3
Which two statements are correct about the customer interface in an LDP-signaled pseudowire? (Choose two)

• A. When the encapsulation is vlan-ccc or extended-vlan-ccc, the configured VLAN tag is not included in the control plane LDP advertisement
• B. When the encapsulation is ethernet-ccc, only frames without a VLAN tag are accepted in the data plane
• C. When the encapsulation is vLan-ccc or extended-vlan-ccc, the configured VLAN tag is included in the control plane LDP advertisement
• D. When the encapsulation is ethemet-ccc, tagged and untagged frames are both accepted in the data plane.

Answer: CD

Explanation:
The customer interface in an LDP-signaled pseudowire is the interface on the PE router that connects to the CE device. An LDP-signaled pseudowire is a type of Layer 2 circuit that uses LDP to establish a point-to-point connection between two PE routers over an MPLS network. The customer interface can have different encapsulation types depending on the type of traffic that is carried over the pseudowire. The encapsulation types are ethernet-ccc, vlan-ccc, extended-vlan-ccc, atm-ccc, frame-relay- ccc, ppp-ccc, cisco-hdlc-ccc, and tcc-ccc. Depending on the encapsulation type, the customer interface can accept or reject tagged or untagged frames in the data plane, and include or exclude VLAN tags in the control plane LDP advertisement. The following table summarizes the behavior of different encapsulation types:

NEW QUESTION 4
Exhibit

Referring to the exhibit, which two statements are true? (Choose two.)

• A. This route is learned through EBGP
• B. This is an EVPN Type-2 route.
• C. The device advertising this route into EVPN is 192.168.101.5.
• D. The devices advertising this route into EVPN are 10 0 2 12 and 10.0.2.22.

Answer: BC

Explanation:
This is an EVPN Type-2 route, also called a MAC/IP advertisement route, that is used to advertise host IP and MAC address information to other VTEPs in an EVPN network. The route type field in the EVPN NLRI has a value of 2, indicating a Type-2 route. The device advertising this route into EVPN is 192.168.101.5, which is the IP address of the VTEP that learned the host information from the local CE device. This IP address is carried in the MPLS label field of the route as part of the VXLAN encapsulation.

NEW QUESTION 5
Which three mechanisms are used by Junos platforms to evaluate incoming traffic for CoS purposes? (Choose three )

• A. rewrite rules
• B. behavior aggregate classifiers
• C. traffic shapers
• D. fixed classifiers
• E. multifield classifiers

Answer: BDE

Explanation:
Junos platforms use different mechanisms to evaluate incoming traffic for CoS purposes, such as:
✑ Behavior aggregate classifiers: These classifiers use a single field in a packet header to classify traffic into different forwarding classes and loss priorities based on predefined or user-defined values.
✑ Fixed classifiers: These classifiers use a fixed field in a packet header to classify traffic into different forwarding classes and loss priorities based on predefined values.
✑ Multifield classifiers: These classifiers use multiple fields in a packet header to classify traffic into different forwarding classes and loss priorities based on user- defined values and filters.
Rewrite rules and traffic shapers are not used to evaluate incoming traffic for CoS purposes, but rather to modify or shape outgoing traffic based on CoS policies.

NEW QUESTION 6
Exhibit

You must ensure that the VPN backbone is preferred over the back door intra-area link as long as the VPN is available. Referring to the exhibit, which action will accomplish this task?

• A. Configure an import routing policy on the CE routers that rejects OSPF routes learned on the backup intra-area link.
• B. Enable OSPF traffic-engineering.
• C. Configure the OSPF metric on the backup intra-area link that is higher than the L3VPN link.
• D. Create an OSPF sham link between the PE routers.

Answer: D

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. To create a sham link, you need to configure the local and remote addresses of the PE routers under the [edit protocols ospf area area-id] hierarchy level1.

NEW QUESTION 7
Exhibit.

Referring to the exhib.t, what must be changed to establish a Level 1 adjacency between routers R1 and R2?

• A. Change the level l disable parameter under the R1 protocols isis interface lo0.0 hierarchy to the level 2 disable parameter.
• B. Remove the level i disable parameter under the R2 protocols isis interface loo . 0 configuration hierarchy.
• C. Change the level 1 disable parameter under the R2 protocols isis interface ge-1/2/3 .0 hierarchy to the level 2 disable parameter
• D. Add IP addresses to the interface ge-l/2/3 unit 0 family iso hierarchy on both R1 and R2.

Answer: B

Explanation:
IS-IS routers can form Level 1 or Level 2 adjacencies depending on their configuration and network topology. Level 1 routers are intra-area routers that share the same area address with their neighbors. Level 2 routers are inter-area routers that can connect different areas. Level 1-2 routers are both intra-area and inter-area routers that can form adjacencies with any other router.
In the exhibit, R1 and R2 are in different areas (49.0001 and 49.0002), so they cannot form a Level 1 adjacency. However, they can form a Level 2 adjacency if they are both configured as Level 1-2 routers. R1 is already configured as a Level 1-2 router, but R2 is configured as a Level 1 router only, because of the level 1 disable command under the lo0.0 interface. This command disables Level 2 routing on the loopback interface, which is used as the router ID for IS-IS.
Therefore, to establish a Level 1 adjacency between R1 and R2, the level 1 disable command under the R2 protocols isis interface lo0.0 hierarchy must be removed. This will enable Level 2 routing on R2 and allow it to form a Level 2 adjacency with R1.

NEW QUESTION 8
A packet is received on an interface configured with transmission scheduling. One of the configured queues In this scenario, which two actions will be taken by default on a Junos device? (Choose two.)

• A. The excess traffic will be discarded
• B. The exceeding queue will be considered to have negative bandwidth credit.
• C. The excess traffic will use bandwidth available from other queueses
• D. The exceeding queue will be considered to have positive bandwidth credit

Answer: AB

Explanation:
Transmission scheduling is a CoS feature that allows you to allocate bandwidth among different queues on an interface. Each queue has a configured bandwidth percentage that determines how much of the available bandwidth it can use. If a queue exceeds its allocated bandwidth, it is considered to have negative bandwidth credit and its excess traffic will be discarded by default. If a queue does not use all of its allocated bandwidth, it is considered to have positive bandwidth credit and its unused bandwidth can be shared by other queues.

NEW QUESTION 9
You are configuring a BGP signaled Layer 2 VPN across your MPLS enabled core network. Your PE-2 device connects to two sites within the s VPN
In this scenario, which statement is correct?

• A. By default on PE-2, the site's local ID is automatically assigned a value of 0 and must be configured to match the total number of attached sites.
• B. You must create a unique Layer 2 VPN routing instance for each site on the PE-2 device.
• C. You must use separate physical interfaces to connect PE-2 to each site.
• D. By default on PE-2, the remote site IDs are automatically assigned based on the order that you add the interfaces to the site configuration.

Answer: D

Explanation:
BGP Layer 2 VPNs use BGP to distribute endpoint provisioning information and set up pseudowires between PE devices. BGP uses the Layer 2 VPN (L2VPN) Routing Information Base (RIB) to store endpoint provisioning information, which is updated each time any Layer 2 virtual forwarding instance (VFI) is configured. The prefix and path information is stored in the L2VPN database, which allows BGP to make decisions about the best path.
In BGP Layer 2 VPNs, each site has a unique site ID that identifies it within a VFI. The site ID can be manually configured or automatically assigned by the PE device. By default, the site ID is automatically assigned based on the order that you add the interfaces to the site configuration. The first interface added to a site configuration has a site ID of 1, the second interface added has a site ID of 2, and so on.
Option D is correct because by default on PE-2, the remote site IDs are automatically assigned based on the order that you add the interfaces to the site configuration. Option A is not correct because by default on PE-2, the site’s local ID is automatically assigned a value of 0 and does not need to be configured to match the total number of attached sites. Option B is not correct because you do not need to create a unique Layer 2 VPN routing instance for each site on the PE-2 device. You can create one routing instance for all sites within a VFI. Option C is not correct because you do not need to use separate physical interfaces to connect PE-2 to each site. You can use subinterfaces or service instances on a single physical interface.

NEW QUESTION 10
Exhibit

R4 is directly connected to both RPs (R2 and R3) R4 is currently sending all ,o,ns upstream to R3 but you want all joins to go to R2 instead Referring to the exhibit, which configuration change will solve this issue?

• A. Change the bootstrap priority on R2 to be higher than R3
• B. Change the default route in inet.2 on R4 from R3 as the next hop to R2
• C. Change the local address on R2 to be higher than R3.
• D. Change the group-range to be more specific on R2 than R3.

Answer: A

Explanation:
PIM Bootstrap Router (BSR) is a mechanism that allows PIM routers to discover and announce rendezvous point (RP) information for multicast groups. BSR uses two roles: candidate BSR and candidate RP. Candidate BSR is the router that collects information from all available RPs in the network and advertises it throughout the network. Candidate RP is the router that wants to become the RP and registers itself with the BSR. There can be only one active BSR in the network, which is elected based on the highest priority or highest IP address if the priority is the same. The BSR priority can be configured manually or assigned automatically. The default priority is 0 and the highest priority is 2515. In this question, R4 is directly connected to both RPs (R2 and R3) and is currently sending all joins upstream to R3 but we want all joins to go to R2 instead. To achieve this, we need to change the BSR priority on R2 to be higher than R3 so that R2 becomes the active BSR and advertises its RP information to R4.
Reference: 1: https://study-ccnp.com/multicast-rendezvous-points-explained/

NEW QUESTION 11
Exhibit

You want Site 1 to access three VLANs that are located in Site 2 and Site 3 The customer- facing interface on the PE-1 router is configured for Ethernet-VLAN encapsulation.
What is the minimum number of L2VPN routing instances to be configured to accomplish this task?

• A. 1
• B. 3
• C. 2
• D. 6

Answer: B

Explanation:
To allow Site 1 to access three VLANs that are located in Site 2 and Site 3, you need to configure three L2VPN routing instances on PE-1, one for each VLAN. Each L2VPN routing instance will have a different VLAN ID and a different VNI for VXLAN encapsulation. Each L2VPN routing instance will also have a different vrf-target export value to identify which VPN routes belong to which VLAN. This way, PE-1 can forward traffic from Site 1 to Site 2 and Site 3 based on the VLAN tags and VNIs.

NEW QUESTION 12
Exhibit

Referring to the exhibit, what do the brackets [ ] in the AS path identify?

• A. They identify the local AS number associated with the AS path if configured on the router, or if AS path prepending is configured
• B. They identify an AS set, which are groups of AS numbers in which the order does not matter
• C. They identify that the autonomous system number is incomplete and awaiting more information from the BGP protocol.
• D. They identify that a BGP confederation is being used to ensure that there are no routing loops.

Answer: B

Explanation:
The brackets [ ] in the AS path identify an AS set, which are groups of AS numbers in which the order does not matter. An AS set is used when BGP aggregates routes from different ASs into a single prefix. For example, if BGP aggregates routes 10.0.0.0/16 and 10.1.0.0/16 from AS 100 and AS 200, respectively, into a single prefix 10.0.0.0/15, then the AS path for this prefix will be [100 200]. An AS set reduces the length of the AS path and prevents routing loops.

NEW QUESTION 13
Exhibit

You want to implement the BGP Generalized TTL Security Mechanism (GTSM) on the network
Which three statements are correct in this scenario? (Choose three)

• A. You can implement BGP GTSM between R2, R3, and R4
• B. BGP GTSM requires a firewall filter to discard packets with incorrect TTL.
• C. You can implement BGP GTSM between R2 and R1.
• D. BGP GTSM requires a TTL of 1 to be configured between neighbors.
• E. BGP GTSM requires a TTL of 255 to be configured between neighbors.

Answer: ADE

Explanation:
BGP GTSM is a technique that protects a BGP session by comparing the TTL value in the IP header of incoming BGP packets against a valid TTL range. If the TTL value is within the valid TTL range, the packet is accepted. If not, the packet is discarded. The valid TTL range is from 255 – the configured hop count + 1 to 255. When GTSM is configured, the BGP packets sent by the device have a TTL of 255. GTSM provides best protection for directly connected EBGP sessions, but not for multihop EBGP or IBGP sessions because the TTL of packets might be modified by intermediate devices.
In the exhibit, we can see that R2, R3, and R4 are in the same AS (AS 20) and R1 is in a different AS (AS 10). Based on this information, we can infer the following statements:
✑ You can implement BGP GTSM between R2, R3, and R4. This is not correct because R2, R3, and R4 are IBGP peers and GTSM does not provide effective protection for IBGP sessions. The TTL of packets between IBGP peers might be changed by intermediate devices or routing protocols.
✑ BGP GTSM requires a firewall filter to discard packets with incorrect TTL. This is not correct because BGP GTSM does not require a firewall filter to discard packets with incorrect TTL. BGP GTSM uses TCP option 19 to negotiate GTSM capability between peers and uses TCP option 20 to carry the expected TTL value in each packet. The receiver checks the expected TTL value against the actual TTL value and discards packets with incorrect TTL values.
✑ You can implement BGP GTSM between R2 and R1. This is correct because R2 and R1 are EBGP peers and GTSM provides effective protection for directly connected EBGP sessions. The TTL of packets between directly connected EBGP peers is not changed by intermediate devices or routing protocols.
✑ BGP GTSM requires a TTL of 1 to be configured between neighbors. This is not correct because BGP GTSM requires a TTL of 255 to be configured between neighbors. The sender sets the TTL of packets to 255 and the receiver expects the TTL of packets to be 255 minus the configured hop count.
✑ BGP GTSM requires a TTL of 255 to be configured between neighbors. This is correct because BGP GTSM requires a TTL of 255 to be configured between neighbors. The sender sets the TTL of packets to 255 and the receiver expects the TTL of packets to be 255 minus the configured hop count.

NEW QUESTION 14
Exhibit

You are examining an L3VPN route that includes the information shown in the exhibit Which statement is correct in this scenario?

• A. The information shows a Type 1 route distinguisher.
• B. The information shows a Type 0 route distinguisher
• C. The information shows a Type 2 route distinguisher.
• D. The information shows a route target

Answer: B

Explanation:
The information shows a Type 0 route distinguisher, which is one of the three types of route distinguishers defined by RFC 4364. A route distinguisher is a 64-bit value that is prepended to an IPv4 address to create a VPN-IPv4 address, which is unique within a VPN routing and forwarding (VRF) table. A Type 0 route distinguisher has two fields: an administrator subfield (2 bytes) and an assigned number subfield (6 bytes). The administrator subfield can be an AS number or an IP address, and the assigned number subfield can be any value assigned by the administrator. In this example, the administrator subfield is 65530 (an AS number) and the assigned number subfield is 1.

NEW QUESTION 15
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.)

• A. set protocols ospf overload timeout 900
• B. set protocols ospf3 realm ipv4-unicast overload timeout 900
• C. set protocols ospf overload
• D. set protocols oapf3 overload timeout 900
• E. set protocols ospf3 overload

Answer: AE

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.

NEW QUESTION 16
You are a network architect for a service provider and want to offer Layer 2 services to your customers You want to use EVPN for Layer 2 services in your existing MPLS network.
Which two statements are correct in this scenario? (Choose two.)

• A. Segment routing must be configured on all PE routers.
• B. VXLAN must be configured on all PE routers.
• C. EVPN uses Type 2 routes to advertise MAC address and IP address pairs learned using ARP snooping
• D. EVPN uses Type 3 routes to join a multicast tree to flood traffic.

Answer: CD

Explanation:
EVPN is a technology that connects L2 network segments separated by an L3 network using a virtual Layer 2 network overlay over the Layer 3 network. EVPN uses BGP as its control protocol to exchange different types of routes for different purposes. Type 2 routes are used to advertise MAC address and IP address pairs learned using ARP snooping from the local CE devices. Type 3 routes are used to join a multicast tree to flood traffic such as broadcast, unknown unicast, and multicast (BUM) traffic.

NEW QUESTION 17
Exhibit

Which two statements about the output shown in the exhibit are correct? (Choose two.)

• A. The PE is attached to a single local site.
• B. The connection has not flapped since it was initiated.
• C. There has been a VLAN ID mismatch.
• D. The PE router has the capability to pop flow labels

Answer: AD

Explanation:
According to 1 and2, BGP Layer 2 VPNs use BGP to distribute endpoint provisioning information and set up pseudowires between PE devices. BGP uses the Layer 2 VPN (L2VPN) Routing Information Base (RIB) to store endpoint provisioning information, which is updated each time any Layer 2 virtual forwarding instance (VFI) is configured. The prefix and path information is stored in the L2VPN database, which allows BGP to make decisions about the best path.
In the output shown in the exhibit, we can see some information about the L2VPN RIB and the pseudowire state. Based on this information, we can infer the following statements:
✑ The PE is attached to a single local site. This is correct because the output shows only one local site ID (1) under the L2VPN RIB section. A local site ID is a unique identifier for a site within a VPLS domain. If there were multiple local sites attached to the PE, we would see multiple local site IDs with different prefixes.
✑ The connection has not flapped since it was initiated. This is correct because the output shows that the uptime of the pseudowire is equal to its total uptime (1w6d). This means that the pseudowire has been up for one week and six days without any interruption or flap.
✑ There has been a VLAN ID mismatch. This is not correct because the output shows that the remote and local VLAN IDs are both 0 under the pseudowire state section. A VLAN ID mismatch occurs when the remote and local VLAN IDs are different, which can cause traffic loss or misdelivery. If there was a VLAN ID mismatch, we would see different values for the remote and local VLAN IDs.
✑ The PE router has the capability to pop flow labels. This is correct because the output shows that the flow label pop bit is set under the pseudowire state section. The flow label pop bit indicates that the PE router can pop (remove) the MPLS flow label from the packet before forwarding it to the CE device. The flow label is an optional MPLS label that can be used for load balancing or traffic engineering purposes.

NEW QUESTION 18
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