Monitor SONET Interfaces

By monitoring SONET interfaces, you begin the process of isolating SONET interface problems when they occur.

To monitor your SONET interface, follow these steps:

Display the Status of SONET Interfaces

Purpose

To display the status of SONET interfaces, use the following Junos OS command-line interface (CLI) operational mode command:

Action

user@host> show interfaces terse so*

Meaning

The sample output lists only the SONET interfaces. It shows the status of both the physical and logical interfaces.

For a description of what the output means, see Table 26.

Table 26: Status of SONET Interfaces

Physical Interface	Logical Interface	Status Description
so-1/0/0 Admin Up Link Up	so-1/0/0.0 Admin Up Link Up	This interface has both the physical and logical links up and running.
so-1/1/1 Admin Down Link Up	so-1/1/1.0 Admin Up Link Down	This interface is administratively disabled. The physical link is healthy (Link Up), but the logical link is not established end to end (Link Down).
so-3/0/1 Admin Up Link Up	so-3/0/1.0 Admin Up Link Down	This interface is administratively enabled and the physical link is healthy (Link Up), but the logical interface is not established end to end (Link Down).
so-5/3/0 Admin Up Link Down	so-5/3/0.0 Admin Up Link Down	This interface has the physical link down and the logical interface is down also.

Physical Interface

Logical Interface

Status Description

so-1/0/0

Admin Up

Link Up

so-1/0/0.0

Admin Up

Link Up

This interface has both the physical and logical links up and running.

so-1/1/1

Admin Down

Link Up

so-1/1/1.0

Admin Up

Link Down

This interface is administratively disabled. The physical link is healthy (Link Up), but the logical link is not established end to end (Link Down).

so-3/0/1

Admin Up

Link Up

so-3/0/1.0

Admin Up

Link Down

This interface is administratively enabled and the physical link is healthy (Link Up), but the logical interface is not established end to end (Link Down).

so-5/3/0

Admin Up

Link Down

so-5/3/0.0

Admin Up

Link Down

This interface has the physical link down and the logical interface is down also.

Display the Status of a Specific SONET Interface

Purpose

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

Action

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

Meaning

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

Meaning

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.

Display Extensive Status Information for a Specific SONET Interface

Purpose

To display extensive status information about a specific interface, use the following Junos OS CLI operational mode command:

Action

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

Sample Output

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

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 statistics:
    Input : 621 (last seen 00:05:35 ago)
    Output: 905 (last seen 00:00:07 ago)
  Statistics last cleared: Never
  Traffic statistics:
   Input  bytes  :            378736540                    0 bps
   Output bytes  :              6786356                    0 bps
   Input  packets:               225924                    0 pps
   Output packets:               104798                    0 pps
   Input errors: 
    Errors: 8, Drops: 0, Framing errors: 4181286, Runts: 0, Giants: 8
    Policed discards: 9474, L3 incompletes: 0, L2 channel errors: 0
    L2 mismatch timeouts: 3, HS link CRC errors: 0, HS link FIFO overflows: 0
   Output errors:  
    Carrier transitions: 2, Errors: 0, Drops: 0, Aged packets: 0
    HS link FIFO underflows: 0
   Active alarms   : LOL, LOS  <--  SONET active alarms and defects
   Active defects  : LOL, LOF, LOS, SEF, AIS-L, AIS-P, PLM-P
  SONET PHY:            Seconds        Count  State  <-- SONET media-specific 
errors
    PLL Lock                  0            0  OK
    PHY Light               328            1  Light Missing
  SONET section: <--  SONET section errors
    BIP-B1                    0            0
    SEF                     329            3  Defect Active
    LOS                     329            2  Defect Active
    LOF                     329            2  Defect Active
    ES-S                    329
    SES-S                   329
    SEFS-S                  329
   SONET line:
    BIP-B2                    0            0
    REI-L                     0            0
    RDI-L                     0            0  OK
    AIS-L                   328            1  Defect Active
    BERR-SF                   0            0  OK
    BERR-SD                   0            0  OK
    ES-L                    329
    SES-L                   329
    UAS-L                   318
    ES-LFE                    0
    SES-LFE                   0
    UAS-LFE                   0
   SONET path:
    BIP-B3                    0            0
    REI-P                     0            0
    LOP-P                     1            1  OK
    AIS-P                   328            1  Defect Active
    RDI-P                     0            0  OK
    UNEQ-P                    0            0  OK
    PLM-P                   328            1  Defect Active
    ES-P                    329
    SES-P                   329
    UAS-P                   318
    ES-PFE                    0
    SES-PFE                   0
    UAS-PFE                   0
[...Output truncated...]

Meaning

The sample output details where the errors might be occurring. Error details include input and output errors, active alarms and defects, and media-specific errors. The SONET section, line, and path errors help narrow down the source of the problem.

If the physical link is down, look at the active alarms and defects for the SONET interface and troubleshoot the SONET media accordingly. SeeList of Common SONET Alarms and Errors for an explanation of SONET alarms.

Monitor Statistics for a SONET Interface

Purpose

To monitor statistics for a SONET interface, use the following Junos OS CLI operational mode command:

Action

user@host> monitor interface so-fpc/pic/port

Caution: We recommend that you use this command only for diagnostic purposes. Do not leave it on during normal router operations because real-time monitoring of traffic consumes additional CPU and memory resources.

Sample Output

user@router> monitor interface so-1/1/1

router                       Seconds: 168                 Time: 15:48:50
Interface: so-1/1/1, Enabled, Link is Down
Encapsulation: Cisco-HDLC, Keepalives, Speed: OC3
Traffic statistics:                                           Current Delta
  Input bytes:                  375527568 (0 bps)                       [0]
  Output bytes:                   6612857 (0 bps)                     [475]
  Input packets:                   224001 (0 pps)                       [0]
  Output packets:                  102090 (0 pps)                      [20]
Encapsulation statistics:
  Input keepalives:                     0                               [0]
  Output keepalives:                  176                              [17]
Error statistics:
  Input errors:                         0                               [0]
  Input drops:                          0                               [0]
  Input framing errors:               179                              [17]
  Policed discards:                    47                               [0]
  L3 incompletes:                       0                               [0]
  L2 channel errors:                    0                               [0]
  L2 mismatch timeouts:                 0                               [0]
  Carrier transitions:                  1                               [0]
  Output errors:                        0                               [0]
  Output drops:                         0                               [0]
  F2      : 0x00  Z3        : 0x00  Z4        : 0x00
Interface warnings:
  o Received keepalive count is zero
  o Framing errors are increasing, check FCS configuration and link
Next='n', Quit='q' or ESC, Freeze='f', Thaw='t', Clear='c', Interface='i'

Meaning

This output checks for and displays common interface failures, whether or not loopback is detected, and any increases in framing errors. Information from this command can help you narrow down possible causes of an interface problem.

Note: If you are accessing the router from the console connection, make sure you set the CLI terminal type using the set cli terminal command.

The statistics in the second column are the cumulative statistics since the last time they were cleared using the clear interfaces statistics interface-name command. The statistics in the third column are the statistics since the monitor interface interface-name command was executed.

If the framing errors are increasing, verify that the frame check sequence (FCS) and scrambling configuration match on both ends of the connection. If the configuration is correct, check the cabling to the router and have the carrier verify the integrity of the line.

If the input errors are increasing, check the cabling to the router and have the carrier verify the integrity of the line.

If you are sending output keepalives but are not receiving any input keepalives, verify that the encapsulation and keepalive configurations match on both ends of the connection.

Table 27 lists and describes the SONET error statistics in the output for the monitor interface command. The output fields are listed in the order in which they appear in the output.

Table 27: SONET Error Statistics

Output Field	Output Field Description
Input errors	Sum of the incoming frame aborts and FCS errors.
Input 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 that is dropped by the ASIC’s random early detection (RED) mechanism.
Input framing errors	The number of packets that have FCS errors.
Policed discards	Frames that the incoming packet match code discarded because they were not recognized or of interest. Usually, this field reports protocols that the Junos OS does not handle.
L3 incompletes	Increments when the incoming packet fails Layer 3 (usually IPv4) sanity checks of the header. For example, a frame with less than 20 bytes of available IP header would be discarded and this counter would increment.
L2 channel errors	Increments when the software cannot find a valid logical interface for an incoming frame.
L2 mismatch timeouts	Count of malformed or short packets that cause the incoming packet handler to discard the frame as unreadable.
Carrier transitions	Number of times the interface has gone from down to up. This number should not increment quickly, increasing only when the cable is unplugged, the far-end system is powered down and up, or a similar problem occurs. If it increments quickly (perhaps once every 10 seconds), then the cable, the far-end system, or the PIC is broken.
Output errors	Sum of the outgoing frame aborts and FCS errors. Because output errors are rare, hardware problems, configuration, or software bugs might contribute to the cause of them. Use the output of the show interfaces type-fpc/pic/port extensive command for more details about which output errors are incrementing. Also, analyze the system or interface load to determine if those areas are contributing to the cause of the problem. If the problem persists, open a case with the Juniper Networks Technical Assistance Center (JTAC) at support@juniper.net or at 1-888-314-JTAC (within the United States) or 1-408-745-9500 (from outside the United States).
Output 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 that is dropped by the ASIC’s RED mechanism.