Step 7: Verify the Status of the Logical Interface

Action

To verify the status of the logical interface, use the following two JUNOS CLI operational mode commands:

user@host> show interfaces so-fpc/pic/port

user@host> show interfaces so-fpc/pic/port terse

Sample Output 1

The following sample output displays the information for a logical interface that is up:

user@host> show interfaces so-2/2/0

Physical interface: so-2/2/0, Enabled, Physical link is Up

Interface index: 21, SNMP ifIndex: 45

Link-level type: Cisco-HDLC, MTU: 4474, Clocking: Internal, SONET mode, Speed: 
OC3, Loopback: None

FCS: 16, Payload scrambler: Enabled

Device flags   : Present Running

Interface flags: Point-To-Point SNMP-Traps

Link flags     : No-Keepalives

Input rate     : 0 bps (0 pps)

Output rate    : 0 bps (0 pps)

SONET alarms   : None

SONET defects  : None

Logical interface so-2/2/0.0 (Index 7) (SNMP ifIndex 33)

Flags: Point-To-Point SNMP-Traps Encapsulation: Cisco-HDLC

Protocol inet, MTU: 4470, Flags: None

Addresses, Flags: Is-Preferred Is-Primary

Destination: 10.0.2/24, Local: 10.0.2.1

user@host> show interfaces so-2/2/0 terse

Interface       Admin Link Proto Local                 Remote

so-2/2/0        up    up

so-2/2/0.0      up    up   inet  10.0.2.1/24     

What It Means

The show interfaces command in sample output 1shows that the logical link is up because there are no flags indicating that the link layer is down. The output for the show interfaces terse command shows that logical interface so-2/2/0.0 is up.

Sample Output 2

The following sample output displays the information for a logical interface that is down:

user@host> show interfaces so-2/2/0

Physical interface: so-2/2/0, Enabled, Physical link is Up

Interface index: 21, SNMP ifIndex: 45

Link-level type: Cisco-HDLC, MTU: 4474, Clocking: Internal, SONET mode, Speed: 
OC3, Loopback: None,

FCS: 16, Payload scrambler: Enabled

Device flags   : Present Running Loop-Detected

Interface flags: Link-Layer-Down Point-To-Point SNMP-Traps

Link flags     : Keepalives

Keepalive settings: Interval 10 seconds, Up-count 1, Down-count 3

Keepalive: Input: 14 (00:00:05 ago), Output: 14 (00:00:05 ago)

Input rate     : 0 bps (0 pps)

Output rate    : 0 bps (0 pps)

SONET alarms   : None

SONET defects  : None

Logical interface so-2/2/0.0 (Index 7) (SNMP ifIndex 33)

Flags: Device-Down Point-To-Point SNMP-Traps Encapsulation: Cisco-HDLC

Protocol inet, MTU: 4470, Flags: None

Addresses, Flags: Dest-route-down Is-Preferred Is-Primary

Destination: 10.0.2/24, Local: 10.0.2.1

user@host> show interfaces so-2/2/0 terse

Interface       Admin Link Proto Local                 Remote

so-2/2/0        up    down

so-2/2/0.0      up    down inet  10.0.2.1/24

What It Means

Both commands in sample output 2 show that the logical interface is down. The first command shows that the link layer, device, and destination route are all down. The second command shows that logical interface so-2/2/0.0 is down.