Step 2: Display the Status of a Specific T1 Interface

Action

To display the status of a specific T1 interface when you need to investigate its status further, use the following JUNOS CLI operational mode command:

user@host> show interfaces t1-fpc/pic/port

Sample Output

user@host> show interfaces t1-1/1/0              

Physical interface: t1-1/1/0, Enabled, Physical link is Down

  Interface index: 24, SNMP ifIndex: 20

  Link-level type: PPP, MTU: 1504, Clocking: Internal, Speed: T1, Loopback: 
None, FCS: 16, Framing: ESF

  Device flags   : Present Running Down

  Interface flags: Hardware-Down Point-To-Point SNMP-Traps

  Link flags     : Keepalives

  Last flapped   : 2002-01-01 00:00:35 UTC (00:00:59 ago)

  Input rate     : 0 bps (0 pps)

  Output rate    : 0 bps (0 pps)

  DS1   alarms   : LOF, LOS

  DS1   defects  : LOF, LOS

What It Means

The first line of the sample output shows the status of the link. In this example, the first line shows that the physical link is down. If the first line shows that the physical link is up, the physical link is healthy and can pass packets. If this line shows that the physical link is down, the physical link is unhealthy and cannot pass packets. Also, the output shows loss of frame (LOF) and loss of signal (LOS) alarms active. Any active alarm or defect can cause the interface to be down.