Step 2: Display the Status of a Specific SONET Interface

Action

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

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

Sample Output

The following sample output is for an interface with the physical link down:

user@router> show interfaces so-1/1/1 

Physical interface: so-1/1/1, Enabled, Physical link is Down

  Interface index: 17, SNMP ifIndex: 16

  Description: router-02 pos 4/0

  Link-level type: Cisco-HDLC, MTU: 4474, Clocking: Internal, SONET mode

  Speed: OC3, Loopback: None, CRC: 32, Payload scrambler: Enabled

  Device flags   : Present Running Down

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

  Link flags     : Keepalives

  Keepalive Input: 621 (00:02:57 ago), Output: 889 (00:00:09 ago)

  Input rate     : 0 bps (0 pps), Output rate: 0 bps (0 pps)

  Active alarms  : LOL, LOS

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

  Logical interface so-1/1/1.0 (Index 18) (SNMP ifIndex 30)

    Description: router-02 pos 4/0

    Flags: Device-down Point-To-Point SNMP-Traps, Encapsulation: Cisco-HDLC

    Protocol inet, MTU: 4470

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

        Destination: 10.10.10.48/30, Local: 10.10.10.50

    Protocol iso, MTU: 4469

What It Means

The first line of the sample output shows that the physical link is down. This means that the physical link is unhealthy and cannot pass packets. Further down the sample output, look for active alarms and defects. When you see this situation, to further diagnose the problem, see Display Extensive Status Information for a Specific SONET Interface to display more extensive information about the SONET interface and the physical interface that is down.

Sample Output

The following output is for an interface with the physical layer up and the link layer down:

user@router> show interfaces so-3/0/1 

Physical interface: so-3/0/1, Enabled, Physical link is Up

  Interface index: 28, SNMP ifIndex: 55

  Description:  Customer ABC

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

  Link flags     : Keepalives

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

  Keepalive: Input: 113 (00:00:02 ago), Output: 119 (00:00:02 ago)

  Input rate     : 80 bps (0 pps)

  Output rate    : 88 bps (0 pps)

  SONET alarms   : None

  SONET defects  : None

  Logical interface so-3/0/1.0 (Index 22) (SNMP ifIndex 56) 

    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: 192.168.2.124/30, Local: 192.168.2.125

What It Means

The sample output shows that the link layer is down. This means that the logical interface is not established end to end. When you see this situation, to further diagnose the problem, see Monitor Statistics for a SONET Interface to monitor statistics for the SONET interface and the logical interface that is down.