This article assists in troubleshooting an issue seen for QFX10K where after the upgrade few of the interfaces are missing from the "show interface <>" output after the upgrade.

• 100G interface not seen in the "show interface" output.

{master:0}

user@qfx10k> show interfaces et-0/0/53 

error: device et-0/0/53 not found

• The optics is present in the "show chassis hardware".
• On further check we can see that in a port group if one of the interface is 100G then other 2 interfaces cannot be used.
• However in the older versions we may have the port with channelized configuration along with 100G speed configuration.
• But on the 20.4 version we have to have all the interfaces in the PG channelized or dechannelized.

[edit chassis fpc 0 pic 0 port 53 speed]

 'speed 100g'

  PIC:0 port:52 configured in 10g speed. Port 53 configured in 100G. Mode is not valid

error: configuration check-out failed

{master:0}[edit]

user@QFX10K# show chassis | display set 

set chassis aggregated-devices ethernet device-count 64

set chassis fpc 0 pic 0 port 51 channel-speed 10g

set chassis fpc 0 pic 0 port 53 speed 100g

{master:0}[edit]

user@QFX10K# set chassis fpc 0 pic 0 port 53 speed 100g 

warning: Port 51 and 52 will be disabled or enabled when port 53 in 100g mode is enabled or disabled

{master:0}[edit]

user@QFX10K# delete chassis fpc 0 pic 0 port 51 channel-speed 10g 

warning: Ports 51 52 53 will be channelized or dechannelized

After committing the above changes the port et-0/0/53 will come up.