What is the primary purpose of Q-in-Q (802.1ad) tunneling in a service provider network?

To encrypt customer traffic to ensure confidentiality across the provider backbone

To carry multiple customer VLANs across a provider network by adding an outer service-provider VLAN tag

To enable routing between customer VLANs at the provider edge

To replace customer VLAN tags with provider VLAN tags to simplify switching

What happens to a customer STP BPDU when it enters a provider switch configured with L2PT?

It is translated into a provider-specific BPDU and forwarded

It is processed by the provider's STP and may affect the provider's spanning tree

It is dropped to prevent loops in the provider network

It is encapsulated with a special MAC address and forwarded across the provider network

Which Junos configuration statement is used to enable L2PT on an interface?

set ethernet-switching-options l2pt interface ge-0/0/1

set interfaces ge-0/0/1 unit 0 l2pt

set protocols l2pt interface ge-0/0/1

A customer reports that their VLAN traffic is not passing through a Q-in-Q tunnel. Which issue is most likely to cause this?

The customer's switch is using a different MAC address

The outer tag on the provider interface does not match the expected service-provider VLAN

The provider network is using OSPF for routing

The customer's VLAN ID is not registered with the provider

A service provider is offering a transparent LAN service to a customer that runs its own spanning tree protocol (STP) across multiple sites. The provider's network also runs STP. The customer's BPDUs must be carried across the provider network without affecting the provider's STP topology. What should the provider implement?

Q-in-Q tunneling on the provider edge interfaces to encapsulate customer BPDUs.

Use a separate VLAN for customer STP traffic and enable STP on that VLAN in the provider core.

Layer 2 Protocol Tunneling (L2PT) on the provider edge interfaces to encapsulate and forward customer STP BPDUs.

Configure the provider edge interfaces as access ports and disable STP on them.

Juniper NetworksCertified Professional, Enterprise Routing and Switching (JNCIP-ENT)

Domain 4Objective 4

Layer 2 Traffic Tunneling (Q-in-Q, L2PT) JN0-650 Practice Questions (Page 1)

Part of the Ethernet Switching and Spanning Tree domain, which makes up ~12% of our current practice bank. Juniper Networks does not publish an official question count, but from its 90-minute exam (~35–60 total, ~4–7 in this domain), expect 1–1 from this objective — we provide 18 practice questions to prepare you well beyond it. (estimate)

18questions here

4free pages

7concepts

Questions 1–5

1foundation · easy
What is the primary purpose of Q-in-Q (802.1ad) tunneling in a service provider network?
Select an answer first
2foundation · easy
What happens to a customer STP BPDU when it enters a provider switch configured with L2PT?
Select an answer first
3foundation · easy
Which Junos configuration statement is used to enable L2PT on an interface?
Select an answer first
4foundation · easy
A customer reports that their VLAN traffic is not passing through a Q-in-Q tunnel. Which issue is most likely to cause this?
Select an answer first
5application · medium
A service provider is offering a transparent LAN service to a customer that runs its own spanning tree protocol (STP) across multiple sites. The provider's network also runs STP. The customer's BPDUs must be carried across the provider network without affecting the provider's STP topology. What should the provider implement?
Select an answer first

Finished these 5 questions?

Review the revealed explanations, or continue through the curriculum.

Next 5 questions →Back to JN0-650

Free Basic Practice is a study aid with revealable answers — not a scored exam. Examers.io is independent and not affiliated with or endorsed by Juniper Networks. “JN0-650” is a trademark of its owner, used for identification only.