Step 1: Display the Status of a Specific ATM1 Interface

Action

To display the status of a specific ATM interface, use the following JUNOS CLI operational mode command:

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

Sample Output

The following sample output is for an ATM1 interface:

user@host> show interfaces at-2/0/1 

Physical interface: at-2/0/1, Enabled, Physical link is Down

  Interface index: 23, SNMP ifIndex: 43

  Link-level type: ATM-PVC, MTU: 4482, Clocking: Internal, SONET mode, Speed: 
OC3, Loopback: None, Payload scrambler: Enabled

  Device flags   : Present Running Down

  Link flags     : None

  Input rate     : 0 bps (0 pps)

  Output rate    : 0 bps (0 pps)

  SONET alarms   : LOL, LOS

  SONET defects  : LOL, LOF, LOS, SEF, AIS-L, AIS-P, RDI-P, PLM-P

  Logical interface at-2/0/1.10 (Index 30) (SNMP ifIndex 65) 

    Flags: Device-Down Point-To-Point SNMP-Traps Encapsulation: ATM-SNAP

  Input packets : 0 

  Output packets: 0

    Protocol inet, MTU: 4470, Flags: None

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

        Destination: 192.168.100.0/30, Local: 192.168.100.1

    VCI 2.100

      Flags: Active

      Total down time: 0 sec, Last down: Never

  Traffic statistics:

       Input  packets:                    0

       Output packets:                    0

What It Means

The first line of the sample output shows that the physical link is down and therefore the logical link is down also. This means that the interface cannot pass packets.

Further down the sample output, look for active alarms and defects. If there are any, and to further diagnose the problem, see Display Extensive Status Information for a Specific ATM1 Interface to display more extensive information about the ATM interface and the physical interface that is down.