A Juniper switch connects to a Cisco switch via a trunk link. The Juniper switch is configured with `set interfaces ge-0/0/2 unit 0 family ethernet-switching port-mode trunk` and `set interfaces ge-0/0/2 unit 0 family ethernet-switching vlan members [10 20 30]`. The Cisco switch is configured with the same allowed VLANs. Frames from VLAN 30 are not being forwarded across the link, but VLANs 10 and 20 work. What is the most likely cause?

The native VLAN on the Juniper trunk is set to VLAN 30, causing a mismatch with the Cisco switch.

The trunk port is configured as access mode on the Juniper switch, so only one VLAN is forwarded.

VLAN 30 is not in the Juniper switch's VLAN database, so the trunk port cannot forward it.

The Cisco switch is not tagging VLAN 30 frames with 802.1Q, so the Juniper switch drops them.

An administrator configures a trunk port on a Juniper switch with `set interfaces ge-0/0/3 unit 0 family ethernet-switching port-mode trunk` and `set interfaces ge-0/0/3 unit 0 family ethernet-switching native-vlan-id 100`. A device connected to the other end of the trunk sends untagged frames. In which VLAN will the Juniper switch place these frames?

The frames are dropped because trunk ports do not accept untagged frames.

The frames are tagged with VLAN 100 before being processed.

VLAN 1, because untagged frames are always placed in the default VLAN.

VLAN 100, because the native VLAN is configured to receive untagged frames.

A network administrator is connecting two Juniper switches with a trunk link. The administrator wants to ensure that VLAN 50 traffic is not sent across the link, but all other VLANs are. Which configuration should be applied to the trunk port?

Set the native VLAN to 50 and include all other VLANs in the members list.

Include all VLANs in the members list except VLAN 50.

Configure the port as an access port in VLAN 50.

Use a firewall filter to block VLAN 50 traffic on the trunk.

A network engineer is connecting a Juniper switch to a legacy switch that does not support 802.1Q tagging. The link must carry traffic for VLAN 10 and VLAN 20. The engineer configures the Juniper trunk port with `native-vlan-id 10` and includes VLAN 20 in the members list. What is the expected behavior?

Both VLAN 10 and VLAN 20 traffic will be untagged.

Both VLAN 10 and VLAN 20 traffic will be tagged with 802.1Q.

VLAN 10 traffic will be untagged, and VLAN 20 traffic will be tagged with 802.1Q.

The link will not work because the legacy switch does not support tagging.

Juniper NetworksCertified Associate, Data Center

Domain 2Objective 2

Port Modes JN0-281 Practice Questions (Page 1)

Part of the Layer 2 Switching and VLANs domain, which makes up ~21% of our current practice bank. Juniper Networks does not publish an official question count, but from its 90-minute exam (~35–60 total, ~7–13 in this domain), expect 1–2 from this objective — we provide 12 practice questions to prepare you well beyond it. (estimate)

12questions here

3free pages

6concepts

Questions 1–5

1application · medium
A Juniper switch connects to a Cisco switch via a trunk link. The Juniper switch is configured with `set interfaces ge-0/0/2 unit 0 family ethernet-switching port-mode trunk` and `set interfaces ge-0/0/2 unit 0 family ethernet-switching vlan members [10 20 30]`. The Cisco switch is configured with the same allowed VLANs. Frames from VLAN 30 are not being forwarded across the link, but VLANs 10 and 20 work. What is the most likely cause?
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2application · easy
An administrator configures a trunk port on a Juniper switch with `set interfaces ge-0/0/3 unit 0 family ethernet-switching port-mode trunk` and `set interfaces ge-0/0/3 unit 0 family ethernet-switching native-vlan-id 100`. A device connected to the other end of the trunk sends untagged frames. In which VLAN will the Juniper switch place these frames?
Select an answer first
3foundation · easy
Which type of link would you configure to allow VLANs 10, 20, and 30 to traverse between two switches?
Select an answer first
4expert · medium
A network administrator is connecting two Juniper switches with a trunk link. The administrator wants to ensure that VLAN 50 traffic is not sent across the link, but all other VLANs are. Which configuration should be applied to the trunk port?
Select an answer first
5expert · hard
A network engineer is connecting a Juniper switch to a legacy switch that does not support 802.1Q tagging. The link must carry traffic for VLAN 10 and VLAN 20. The engineer configures the Juniper trunk port with `native-vlan-id 10` and includes VLAN 20 in the members list. What is the expected behavior?
Select an answer first

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Port Modes JN0-281 Practice Questions (Page 1)

Questions 1–5

Which type of link would you configure to allow VLANs 10, 20, and 30 to traverse between two switches?

A network administrator is connecting two Juniper switches with a trunk link. The administrator wants to ensure that VLAN 50 traffic is not sent across the link, but all other VLANs are. Which configuration should be applied to the trunk port?

Keep studying — Layer 2 Switching and VLANs