Description

When a 100G transceiver is a fiber cable, then the port won't come up and when a 100G transceiver is a DAC (Direct Attach Copper) cable, then the port will come up as 40G instead of 100G. The CLI command "show interfaces vcp-<> extensive" will show the speed as 40G.

Solution

PR specifies this applies for all QFX platform (Junos). Also, we can confirm the issue is seeing right away port is configured as VC port, and will happen only with 100g DAC/fiber cables. Besides, interfaces will show as 40G instead for 100G:

 

root@device> show interfaces vcp-<> extensive

 

Physical interface: vcp-<>, Enabled, Physical link is Down

Interface index: 128, SNMP ifIndex: 0, Generation: 131

Type: 105, Link-level type: Virtual-Chassis-Interface, MTU: 1514, Clocking: Unspecified, Speed: 40000mbps <<< Speed will be set as 40G.

We can see triggers for the same below:

 

This issue might be seen if the following conditions are met:

* On Junos QFX5110 and QFX5120 platforms

* 100G transceiver (DAC/Fiber) as VC port or network port.

Resolved In
Junos
22.1R3-S5
22.2R3-S1
22.2R3-S3
22.3R2-S1
22.3R3
22.3R3-S2
22.4R2
22.4R3
23.1R2
23.2R1
23.2R2
23.3R1
23.3R2

PR link: https://prsearch.juniper.net/problemreport/PR1711407

Modification History

2023-10-25 : Article Created