JN0-102 · Question #344
Which command would initiate a loopback on a Gigabit Ethernet interface ge-0/0/0?
The correct answer is B. # set interfaces ge-0/0/0 gigether-options loopback. To initiate a physical loopback on a Gigabit Ethernet interface in Junos, the set interfaces command is used with the gigether-options loopback stanza in configuration mode. This command specifically enables the hardware loopback function on the specified interface.
Question
Which command would initiate a loopback on a Gigabit Ethernet interface ge-0/0/0?
Options
- A
set interfaces ge-0/0/0 unit 0 loopback
- B
set interfaces ge-0/0/0 gigether-options loopback
- C
set interfaces ge-0/0/0 loopback
- D
loopback ge-0/0/0
How the community answered
(23 responses)- A9% (2)
- B87% (20)
- D4% (1)
Why each option
To initiate a physical loopback on a Gigabit Ethernet interface in Junos, the `set interfaces` command is used with the `gigether-options loopback` stanza in configuration mode. This command specifically enables the hardware loopback function on the specified interface.
The `unit 0 loopback` command configures a logical loopback on a logical interface, not a physical hardware loopback on the GE interface itself.
The `set interfaces ge-0/0/0 gigether-options loopback` command is the correct way to configure a hardware loopback on a physical Gigabit Ethernet interface in Junos configuration mode. This places the interface into a loopback state at the physical layer for diagnostic purposes.
Commands starting with `>` are operational mode commands, not configuration mode commands for persistent changes.
This command syntax is incorrect and not a valid Junos command for configuring loopback.
Concept tested: Configuring interface physical loopback
Source: https://www.juniper.net/documentation/us/en/software/junos/interfaces-app-services/topics/topic-map/interfaces-loopback-mode.html
Topics
Community Discussion
No community discussion yet for this question.