Interfaces remain in "Up Down" state even though the light levels are good on the port.
Labuser@labrouter> show interfaces et-0/1/0
Aug 15 01:54:32
Physical interface: et-0/1/0, Enabled, Physical link is Down
Interface index: 180, SNMP ifIndex: 554
Description: AE18:LAG:
Link-level type: Flexible-Ethernet, MTU: 9176, LAN-PHY mode, Speed: 100Gbps, BPDU Error: None, Loop Detect PDU Error: None, Ethernet-Switching Error: None, MAC-REWRITE Error: None, Loopback: Disabled, Source filtering: Disabled, Flow control: Disabled, Media type: Fiber
Device flags : Present Running Down
Interface flags: Hardware-Down SNMP-Traps Internal: 0x4000
CoS queues : 8 supported, 8 maximum usable queues
Current address: 50:c7:09:8b:09:3c, Hardware address: 50:c7:09:8b:01:c0
Last flapped : 2024-08-14 23:41:00 CDT (02:13:32 ago)
Input rate : 0 bps (0 pps)
Output rate : 0 bps (0 pps)
Active alarms : LINK
Active defects : LINK, LOCAL-FAULT
PCS statistics Seconds
Bit errors 0
Errored blocks 0
Ethernet FEC Mode : FEC91
Ethernet FEC statistics Errors
FEC Corrected Errors 0
FEC Uncorrected Errors 0
FEC Corrected Errors Rate 0
FEC Uncorrected Errors Rate 0
PRBS Statistics : Disabled
Interface transmit statistics: Disabled
Labuser@Labrouter> show interfaces diagnostics optics et-0/1/0
Aug 15 01:50:36
Physical interface: et-0/1/0
Module temperature : 32 degrees C / 90 degrees F
Module voltage : 3.2550 V
Module temperature high alarm : Off
Module temperature low alarm : Off
Module temperature high warning : Off
Module temperature low warning : Off
Module voltage high alarm : Off
Module voltage low alarm : Off
Module voltage high warning : Off
Module voltage low warning : Off
Module temperature high alarm threshold : 75 degrees C / 167 degrees F
Module temperature low alarm threshold : -5 degrees C / 23 degrees F
Module temperature high warning threshold : 70 degrees C / 158 degrees F
Module temperature low warning threshold : 0 degrees C / 32 degrees F
Module voltage high alarm threshold : 3.5990 V
Module voltage low alarm threshold : 3.0790 V
Module voltage high warning threshold : 3.4700 V
Module voltage low warning threshold : 3.0990 V
Laser bias current high alarm threshold : 89.999 mA
Laser bias current low alarm threshold : 4.999 mA
Laser bias current high warning threshold : 79.999 mA
Laser bias current low warning threshold : 9.999 mA
Laser output power high alarm threshold : 2.8184 mW / 4.50 dBm
Laser output power low alarm threshold : 0.3548 mW / -4.50 dBm
Laser output power high warning threshold : 2.5119 mW / 4.00 dBm
Laser output power low warning threshold : 0.3981 mW / -4.00 dBm
Laser rx power high alarm threshold : 2.8184 mW / 4.50 dBm
Laser rx power low alarm threshold : 0.0692 mW / -11.60 dBm
Laser rx power high warning threshold : 2.5119 mW / 4.00 dBm
Laser rx power low warning threshold : 0.0871 mW / -10.60 dBm
Lane 0
Laser bias current : 46.793 mA
Laser output power : 1.524 mW / 1.83 dBm
Laser receiver power : 1.480 mW / 1.70 dBm
Laser bias current high alarm : Off
Laser bias current low alarm : Off
Laser bias current high warning : Off
Laser bias current low warning : Off
Laser receiver power high alarm : Off
Laser receiver power low alarm : Off
Laser receiver power high warning : Off
Laser receiver power low warning : Off
Tx loss of signal functionality alarm : Off
Rx loss of signal alarm : Off
Tx laser disabled alarm : Off
Lane 1
Laser bias current : 43.917 mA
Laser output power : 1.205 mW / 0.81 dBm
Laser receiver power : 1.152 mW / 0.61 dBm
Lane 2
Laser output power : 1.402 mW / 1.47 dBm
Laser receiver power : 0.999 mW / -0.00 dBm
Lane 3
Laser bias current : 44.624 mA
Laser output power : 1.405 mW / 1.48 dBm
Laser receiver power : 1.292 mW / 1.11 dBm
Labuser@labrouter> show chassis pic fpc-slot 0 pic-slot 1
Aug 15 01:58:05
FPC slot 0, PIC slot 1 information:
Type 16x10/25GE 4x40/100GE Builtin
State Online
Uptime 2 hours, 17 minutes, 11 seconds
PIC port information:
Fiber Xcvr vendor Wave- Xcvr JNPR
Port Cable type type Xcvr vendor part number length Firmware Rev
0 100GBASE LR4 T2 SM PROLABS JNP-QSFP100G-LR4 1310 nm 0.0 REV 01
1 100GBASE LR4 T2 SM PROLABS JNP-QSFP100G-LR4 1310 nm 0.0 REV 01
Here in this case, ports/interfaces are down due to FEC mismatch. Correcting the Interface FEC mode resolved the issue
Labuser@labrouter# show | compare
Aug 15 02:00:37
[edit interfaces et-0/1/0]
+ gigether-options {
+ fec none;
+ }
Aug 15 02:00:59
Physical interface: et-0/1/0, Enabled, Physical link is Up
Device flags : Present Running
Interface flags: SNMP-Traps Internal: 0x4000
Last flapped : 2024-08-15 02:00:48 CDT (00:00:11 ago)
Active alarms : None
Active defects : None
Ethernet FEC Mode : NONE