Description

Customer sometimes may need one port to operate as 10G and rest ports run as 1G on QFX5120-48Y switches.

Unfortunately, this port-speed combination is not available.

Symptoms

One 10G port failed to come up after applying CLI command "set chassis fpc 0 pic 0 port-range 0 47 channel-speed disable-auto-speed-detection".

Example:

{master:0}
labroot@jtac-qfx5120-48y-8c-r2010> show configuration chassis | display set
Jul 04 04:24:41
set chassis fpc 0 pic 0 port-range 0 47 channel-speed disable-auto-speed-detection

{master:0}
labroot@jtac-qfx5120-48y-8c-r2010> show interfaces terse xe-0/0/7          
Jul 04 04:25:03

Interface              Admin Link Proto   Local                Remote
xe-0/0/7               up   down
xe-0/0/7.16386         up   down                <<<<<<<<<<<<<<

Solution

QFX5120-48Y switches work on a “quad-port” mode in which 4x consecutive physical ports must be working on the same speed as per PR1745720.

For example, ports 4 to 7 must be all operating as 10G if we need one of them to run as 10G. Plus, default port speed for the first 48 ports on QFX5120-48Y switches is 10G.


With that said, customer has to manually configure 1G or 25G port speed with “quad-port” mode via CLI commands “set chassis fpc <fpc_number pic <pic_number> port <port_number> speed 1G/25G” or remove the configuration if they need 10G ports.
 

Modification History

For Publish