JN0-680: Data Center, Professional - Free download from ExamHUB

A customer has built a VXLAN using an EVPN signaling infrastructure with remote facilities with VXLAN using EVPN signaling connected to the Internet. The customer notices that the network is completely stable with no protocol errors in the underlay or overlay. The customer, however, cannot pass any application data across the network.

Which statement would explain the intermittent loss?

There is an LACP key mismatch.
The MTU is exceeded.
The routing protocol authentication has failed.
The BPDU protection is invoked.

Correct answer: D

You have deployed a multicast server attached to a QFX5100 Series device serving as a VTEP.

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

By default, the QFX5100 will send copies of the multicast packets to all locally attached devices in the same VLAN.
By default, the QFX5100 will send copies of the multicast packets to locally attached devices in the same VLAN that are interested receivers only.
By default, the QFX5100 will encapsulate the multicast packets in VXLAN and forward them to all remotely connected VTEPs.
By default, the QFX5100 will encapsulate the multicast packets in VXLAN and forward them to remotely connected VTEPs with interested receives only.

Correct answer: AC

Explanation:

Reference: https://www.juniper.net/documentation/en_US/junos/topics/topic-map/sdn-vxlan.html#jd0e168

Which protocol is used between VCF member devices to create a loop-free topology?

LLDP
MSTP
RSTP
VCCP

Correct answer: D

Explanation:

Reference: http://www.juniper.net/documentation/en_US/release-independent/vcf/information-products/pathway-pages/vcf-best-practices-guide.pdf

Referring to the exhibit, each leaf node is a QFX5100 acting as a VXLAN Layer 2 Gateway using EVPN signaling. Leaf 2 and Leaf 3 are both attached to the same EVPN Ethernet segment. Leaf 2 has been elected the designated forwarder for VLAN 200 on that Ethernet segment.

In this scenario, which two actions will Leaf 1 perform with the broadcast Ethernet frame received from Host A? (Choose two.)

Leaf 1 will strip the VLAN tag from the Ethernet frame before encapsulating it in VXLAN.
Leaf 1 will send a VXLAN encapsulated copy of the Ethernet frame to both Leaf 2 and Leaf 3.
Leaf 1 will change the VLAN tag of the Ethernet frame to 200 before encapsulating it in VXLAN.
Leaf 1 will send a VXLAN encapsulated copy of the Ethernet frame to Leaf 2 only.

Correct answer: AD

Explanation:

Reference: https://www.juniper.net/documentation/en_US/junos/topics/topic-map/sdn-vxlan.html

You have built a mixed-mode VCF consisting of two QFX5100-24Qs as spines, two QFX5100-48S as leaf nodes, and one EX4300 as a leaf node. The VCF is working for all devices, except the EX4300 40GbE fabric links will not join the VCF.

In this scenario, what must be corrected to solve the connectivity problem?

Reboot all of the VCF members.
Power off all of the VCF members and power up the spines before powering up the leafs.
Zeroize the EX4300, cleat all the tables with the clear ethernet-switching tables command on all members, and reissue the request virtual-chassis mixed-mode command.
Turn off authonegotiation on the EX4300 and the attached spine interfaces, and then use the request virtual-chassis vc-port set command on the spine ports connected to the EX4300.

Correct answer: A

Explanation:

Reference: https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/vcf-adding-device.html(Required only if you are adding a device that turns a non-mixed VCF into a mixed VCF) Log in to the VCF and set all devices in the VCF to mixed mode. Configure all devices to reboot to complete this procedure. user@device> request virtual-chassis mode mixed all-members reboot The VCF experiences downtime as part of the reboot step.

Reference: https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/vcf-adding-device.html

(Required only if you are adding a device that turns a non-mixed VCF into a mixed VCF) Log in to the VCF and set all devices in the VCF to mixed mode. Configure all devices to reboot to complete this procedure.

user@device> request virtual-chassis mode mixed all-members reboot

The VCF experiences downtime as part of the reboot step.

Your server administrator asks you to preserve the inner VLAN tags of the frames coming from a Layer 2 VXLAN Gateway of the EVPN-enabled segment.

Which two parameters must you add to the configuration to allow the VLAN tag to be passed? (Choose two.)

layer2-protocol-tunneling
decapsulate-accept-inner-vlan
dotlq-tunneling
encapsulate-inner-vlan

Correct answer: BD

Explanation:

Reference: https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/encapsulate-inner-vlan.htmlReference: https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/decapsulate-accept-inner-vlan.html

Reference: https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/encapsulate-inner-vlan.html

Reference: https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/decapsulate-accept-inner-vlan.html

Which two statements are correct when performing a unified ISSU? (Choose two.)

The master Routing Engine and backup Routing Engine must be running the same software version before you can perform a unified ISSU.
Unicast RPF-related statistics are not saved across a unified ISSU, and the unicast RPF counters are reset to zero during a unified ISSU.
Unicast RPF-related statistics are saved across a unified ISSU, and the unicast RPF counters are not reset to zero during a unified ISSU.
The backup Routing Engine must be running the most recent software version before you can perform a unified ISSU.

Correct answer: AB

Explanation:

Reference: https://www.juniper.net/documentation/en_US/junos/topics/reference/requirements/issu-system-requirements.html

In a preprovisioned mixed Virtual Chassis, which statement is correct about converting a 40Gbps QSFP+ to a Virtual Chassis port in an EX4300?

LLDP is enabled on that interface.
LLDP is disabled on that interface.
One end of the link is configured as a Virtual Chassis port.
Both ends of the link have the default configuration.

Correct answer: D

Explanation:

Reference: https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/virtual-chassis-qfx-series-cli.html

You are implementing a Virtual Chassis using QFX5100s and EX4300s in your data center.

In this scenario, which three hardware capabilities are affected? (Choose three.)

usable VCP connections limited to 10GbE
MAC table size
number of usable ports per member
number of supported routing instances
maximum number of firewall filters

Correct answer: BDE

Explanation:

Reference: http://africa.westcon.com/documents/54080/ex-series-qfx-series-switching-product-comparison-matrix.pdf

You are developing an EVPN service between your data centers to enable Layer 2 stretch and Virtual Machine Traffic Optimization (VMTO) operations.

In this scenario, which action must be performed on the IRB interface to accomplish this task?

Configure the same IP address and let the MAC address be dynamically assigned on each PE.
Configure the same IP address and the same MAC address on each PE.
Configure different IP addresses but the same MAC address on each PE.
Configure different IP addresses and different MAC addresses on each PE.

Correct answer: B

Explanation:

Reference: https://www.juniper.net/documentation/en_US/release-independent/solutions/information-products/pathway-pages/solutions/l3gw-vmto-evpn-vxlan-mpls.pdf