close

keyboard_arrow_left

Table of Contents Expand all

list Table of Contents

English

show interfaces (Loopback)

date_range 04-Dec-23

arrow_backward

arrow_forward

Syntax

content_copy zoom_out_map
show interfaces lo0
<brief | detail | extensive | terse>
<descriptions>
<media>
<snmp-index snmp-index>
<statistics>

Description

Display status information about the local loopback interface.

Note:

Logical interface lo0.16385 is the loopback interface for the internal routing instance. Created by the internal routing service process, this interface facilitates internal traffic. It prevents any filter created on loopback lo0.0 from blocking internal traffic.

Options

lo0	Display standard status information about the local loopback interface.
brief \| detail \| extensive \| terse	(Optional) Display the specified level of output.
descriptions	(Optional) Display interface description strings.
media	(Optional) Display media-specific information.
snmp-index `snmp-index`	(Optional) Display information for the specified SNMP index of the interface.
statistics	(Optional) Display static interface statistics.

Required Privilege Level

view

Output Fields

Table 1 lists the output fields for the show interfaces (loopback) command. Output fields are listed in the approximate order in which they appear.

Table 1: Loopback show interfaces Output Fields
Field Name	Field Description	Level of Output
Physical Interface
`Physical Interface`	Name of the physical interface.	All levels
`Enabled`	State of the interface. Possible values are described in the “Enabled Field” section under Common Output Fields Description.	All levels
`Interface index`	Physical interface index number, which reflects its initialization sequence.	`detail extensive` none
`SNMP ifIndex`	SNMP index number for the physical interface.	`detail extensive` none
`Generation`	Unique number for use by Juniper Networks technical support only.	`detail extensive`
`Type`	Type of interface.	All levels
`Link-level type`	Encapsulation type used on the physical interface.	All levels
`MTU`	Size of the largest packet to be transmitted.	All levels
`Clocking`	Reference clock source of the interface.	All levels
`Speed`	Network speed on the interface.	All levels
`Device flags`	Information about the physical device. Possible values are described in the “Device Flags” section under Common Output Fields Description.	All levels
`Interface flags`	Information about the interface. Possible values are described in the “Interface Flags” section under Common Output Fields Description.	All levels
`Link type`	Data transmission type.	`detail extensive`
`Link flags`	Information about the link. Possible values are described in the “Link Flags” section under Common Output Fields Description.	`detail extensive` none
`Physical info`	Information about the physical interface.	`detail extensive`
`Hold-times`	Current interface hold-time up and hold-time down. Value is in milliseconds.	`detail extensive`
`Current address`	Configured MAC address.	`detail extensive`
`Hardware address`	Media access control (MAC) address of the interface.	`detail extensive`
`Alternate link address`	Backup link address.	`detail extensive`
`Last flapped`	Date, time, and how long ago the interface went from down to up. The format is `Last flapped: year-month-day hour:minute:second timezone (hour:minute:second ago)`. For example, `Last flapped: 2002-04-26 10:52:40 PDT (04:33:20 ago)`.	`detail extensive`
`Statistics last cleared`	Time when the statistics for the interface were last set to zero.	`detail extensive`
`Traffic statistics`	Number and rate of bytes and packets received and transmitted on the physical interface. `Input bytes, Output bytes`—Number of bytes received and transmitted on the interface. `Input packets, Output packets`—Number of packets received and transmitted on the interface.	`detail extensive`
`Input errors`	`Errors`—Input errors on the interface. `Drops`—Number of packets dropped by the output queue of the I/O Manager ASIC. `Framing errors`—Number of packets received with an invalid frame checksum (FCS). `Runts`—Frames received smaller than the runt threshold. `Giants`—Frames received larger than the giant threshold. `Policed Discards`—Frames that the incoming packet match code discarded because the frames were not recognized or were not of interest. Usually, this field reports protocols that Junos does not support. `Resource errors`—Sum of transmit drops.	`extensive`
`Output errors`	`Carrier transitions`—Number of times the interface has gone from `down` to `up`. This number does not normally increment quickly, increasing only when the cable is unplugged, the far-end system is powered down and then up, or another problem occurs. If the number of carrier transitions increments quickly, possibly once every 10 seconds, the cable, the remote system, or the interface is malfunctioning. `Errors`—Sum of outgoing frame terminations and FCS errors. `Drops`—Number of packets dropped by the output queue of the I/O Manager ASIC. If the interface is saturated, this number increments once for every packet dropped by the ASIC RED mechanism. `MTU errors`—Number of packets larger than the MTU threshold. `Resource errors`—Sum of transmit drops.	`extensive`
Logical Interface
`Logical interface`	Name of the logical interface.	All levels
`Index`	Logical interface index number, which reflects its initialization sequence.	`detail extensive`
`SNMP ifIndex`	Logical interface SNMP interface index number.	`detail extensive`
`Generation`	Unique number for use by Juniper Networks technical support only.	`detail extensive`
`Flags`	Information about the logical interface; values are described in the “Logical Interface Flags” section under Common Output Fields Description.	`brief detail extensive`
`Encapsulation`	Encapsulation on the logical interface.	`brief detail extensive`
`Input packets`	Number of packets received on the logical interface.	None specified
`Output packets`	Number of packets transmitted on the logical interface.	None specified
`Traffic statistics`	Total number of bytes and packets received and transmitted on the logical interface. These statistics are the sum of the local and transit statistics. When a burst of traffic is received, the value in the output packet rate field might briefly exceed the peak cell rate. It takes awhile (generally, less than 1 second) for this counter to stabilize.	`detail extensive`
`Local statistics`	Statistics for traffic received from and transmitted to the Routing Engine. When a burst of traffic is received, the value in the output packet rate field might briefly exceed the peak cell rate. It takes awhile (generally, less than 1 second) for this counter to stabilize.	`detail extensive`
`Protocol`	Protocol family configured on the logical interface (such as `iso` or `inet6`).	`detail extensive` none
`MTU`	MTU size on the logical interface.	`detail extensive` none
`Generation`	Unique number for use by Juniper Networks technical support only.	`detail extensive`
`Route Table`	Route table in which this address exists; for example, `Route table:0` refers to inet.0.	`detail extensive`
`Flags`	Information about the protocol family flags. Possible values are described in the “Family Flags” section under Common Output Fields Description.	`detail extensive` none
`Addresses, Flags`	Information about the address flags. Possible values are described in the “Addresses Flags” section under Common Output Fields Description.	`detail extensive`
`Destination`	IP address of the remote side of the connection.	`detail extensive` none
`Local`	IP address of the logical interface.	`detail extensive` none
`Broadcast`	Broadcast address on the logical interface.	`detail extensive` none
`Generation`	Unique number for use by Juniper Networks technical support only.	`detail extensive`

Sample Output