Hi, Not all MPCs support breakouts. You can check on the ability with of the PIC and what speeds it can breakout. show chassis pic fpc-slot <fpc> pic-slot <pic> Output on a MPC7E-MRATE will show the following. For example, while the MPC7E-MRATE supports 4x10 breakouts, it doesn’t support 4x25 on a 100G capable port. mx> show chassis pic fpc-slot 4 pic-slot 0 | find "Port speed information" Port speed information: Port PFE Capable Port Speeds 0 0 4x10GE, 40GE 1 0 4x10GE, 40GE 2 0 4x10GE, 40GE, 100GE 3 0 4x10GE, 40GE 4 0 4x10GE, 40GE 5 0 4x10GE, 40GE, 100GE {master} mx> If the PIC can handle it, the port can be configured by setting it to 10G. mx> show configuration chassis fpc 4 pic 1 port 0 | display set set chassis fpc 4 pic 1 port 0 speed 10g Hope that helps, -- Trent From: NANOG <nanog-bounces+trent=dingo.net.au@nanog.org> On Behalf Of Paschal Masha Sent: Thursday, February 24, 2022 16:47 To: nanog <nanog@nanog.org> Subject: 40G QSFP+ to 4 SFP+ on MX960 Hello, Has anyone managed to get the 40G QSFP+ to 4 SFP+ breakout cable to work on the 2X40GE QSFPP Juniper MICs? Which commands did you use to channelize the port under the "chassis fpc" mode to get it to channelize to 4x10g at least for one 40G port on that MIC? My device : MX960. On a side note, 40G modules/ports are a waste from a design perspective. Thanks in advance Regards Paschal Masha | Engineering Skype ID: paschal.masha <http://zuku.co.ke/es/sig_img.jpg>