Users may find that the physical interface in a Juniper Networks EX or QFX Series Switch is not listed in the show interface command output.
In this article, you will find the steps to troubleshoot this problem when it occurs.
Although an interface is configured, the following error message is reported when the show interfaces <interface> command is run.
Example
root@switch> show interfaces ge-0/1/0 error: device ge-0/1/0 not found
As an example, consider that the following interface is not found:
And the output of the show virtual-chasses vc-port command shows that the configured interface is Absent:
root@switch> show virtual-chassis vc-port fpc0: -------------------------------------------------------------------------- Interface Type Trunk Status Speed Neighbor or ID (mbps) ID Interface PIC / Port vcp-0 Dedicated 1 Down 32000 vcp-1 Dedicated 2 Down 32000 1/0 Configured Absent
If the expected Physical Interface is not listed as shown in the above output, refer to the following possible causes:
The interface is an optical interface with one of the following problems:
The interface may not have a transceiver installed or inserted, or it is not fully connected.
The transceiver that is connected to the interface may not be detected due to the following:
Compatibility: Dead transceiver
1G transceivers will not be detected in EX4200/EX3200 SFP+ modules on interfaces 1 and 3, because these interfaces are 10G by default.
The transceiver may not be compatible with the EX/QFX switch interface into which it is being inserted. (We recommend that you use transceivers that are compatible with Juniper EX switches. Third party transceivers are not guaranteed to work.)
A Juniper manufactured transceiver is not necessarily compatible with EX Series switches. Refer to the Juniper Hardware Compatibility Tool and verify that the Junos OS version that your device is running supports this transceiver.
Dead cable
Patch panel
Range of the transceiver (Long, Short, Medium)
Third party device in between (Attenuator, Amplifier, Repeater):
Fiber optic attenuator is a passive device that is used to reduce the amplitude of a light signal without significantly changing the wave form itself.
Used to convert long range transceivers into short range
Fiber optic amplifier is used to compensate for weakening of information during transmission because of fiber optic attenuation.
Fiber optic repeater can also serve this purpose, but it is not good enough. It can function only on a specific wavelength and is not suitable for WDM systems.
Used to convert short range transceivers into long range
For example, the following interface is not found:
root@Kswitch> show interfaces ge-3/0/0 error: device ge-3/0/0 not found
And the output of the command show virtual-chassis shows that a member is NotPrsnt:
root@switch> show virtual-chassis Preprovisioned Virtual Chassis Virtual Chassis ID: 6eb0.0094.e64b Mastership Neighbor List Member ID Status Serial No Model priority Role ID Interface 0 (FPC 0) Prsnt BR0208233776 ex4200-24f 128 Backup 1 vcp-0 1 (FPC 1) Prsnt BR0209456997 ex4200-24f 128 Master* 3 vcp-0 0 vcp-1 2 (FPC 2) Prsnt BR0208233803 ex4200-24f 128 Linecard 3 vcp-1 3 (FPC 4) NotPrsnt BP0208180138 ex4200-48t
If this is the symptom, refer to KB21064 - [EX] Resolution Guide - Troubleshoot Virtual Chassis (VC) [juniper.net] to correct the issue.
The interface may be configured as a Virtual Chassis (VC) Port. In this example, the interface ge-0/1/0 has been configured as a VC-Port; hence, it will not show up in the Interface Terse Output.
To correct this, refer to the instructions on setting an Uplink Port as a Virtual Chassis Port:
CLI Procedure
For Legacy Devices: LCD Procedure
The interface may be auto-channelized. Refer to KB32409 - [QFX] EX4600/QFX5100/QFX5200 interfaces are auto-channelized while connecting with QFX10K [juniper.net] to disable auto-channel-speed-detection.
For QFX10000 family, the port might be a shared port that is disabled on the port group. Refer to QFX10000 Linecards to verify that the port is supposed to be disabled.
If the Juniper device is a QFX5120-48Y or an EX4650-48Y, and you are connecting a 1G transceiver, follow the instructions provided in KB35439 - [QFX/EX] Configuring 1G and 25G ports on QFX5120-48Y(M) and EX4650-48Y [juniper.net].
2020-02-06: Added QFX
2022-06-09 Added links to troubleshoot transceivers for auto-channelized interfaces, port groups, and 1g transceivers on QFX5120