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QFX5100 48T - Configure QSFP slot for QSFP-SR4 optics

‎12-13-2018 09:32 AM

Hi all,


We are trying to use the QSFP ports on our QFX5100s.  We are wanting to use a full 40GE interface by using an SR4 optic to uplink to our MX core router.  The MX picked up the optics and show them as et interfaces, but the QFX is not picking them up.


When I try to configure them, all I can get is to the channelized 10G, but no options for 40.  

The optics do not register in the "show chassis hardware" and I am not sure how to declare those ports as 40Ge.


Anyone have experience with this or know how to set it up?

I have tried looking through documentation, but I can't seem to find anything on this.



Ethernet Switching

Re: QFX5100 48T - Configure QSFP slot for QSFP-SR4 optics

‎12-13-2018 11:59 AM

I would suggest that you disable auto-channelization as mentioned on


By default, the 40-Gbps QSFP+ ports on EX4600 and QFX5100 switches are channelized automatically (auto-channelized) if any of the four channels on a 40-Gbps QSFP+ port receive data, unless you have configured channelization either at the chassis level or at the port level. Auto-channelization is not supported on interfaces contained in expansion modules, or on Virtual Chassis ports. 

You can disable auto-channelization by including the disable-auto-speed-detection statement at the [edit chassis fpc slot-number pic pic-number (port port-number | port-range port-range-low port-range-high) channel-speed] hierarchy

It could also be that the ports are defined as virtual-chassis ports. Does 'show virtual-chassis vc-port' output any ports? If yes, then remove them via 'request virtual-chassis vc-port delete pic-slot 0 port X'


If you are still stuck, then provide output from 'show chassis hardware' and configuration related to interfaces and chassis.

Best regards,

Jonas Hauge Klingenberg
Juniper Ambassador & Technology Architect, SEC DATACOM A/S (Denmark)