CRS504-4XQ with 100G-SR4

[franknord]

Hi,

I just received a CRS504-4XQ, but have issues getting the 100G links to work.
I moved one side of a working 100G-SR4 link between two Juniper QFX5210-32C to the CRS.
However, the link remains down on Router OS 7.8 and 7.9rc2.
I changed FEC to fec91 on the Mikrotik side as “auto” showed a disappearing SFP in /interface/ethernet/monitor qsfp28-4-1.
It is now matching FEC on the Juniper-side. While this didn’t help, I switched to FEC none on both sides.
The Mikrotik-side shows link-up for about 15s just to flap again, Juniper-side stays down.

Another question is how I can get rid of the breakout interfaces, as this is 1x 100G and we do not intend to split into 4x25G or 4x10G.

Any other ideas?

Cheers,
Frank

[sjoko]

Hi Franknord,
were you able to solve this ?
I'm experiencing similar connectivity problems connecting a satellite device QFX5200 to a mikrotik CRS518-16XS-2XQ-RM at 100G

[sjoko]

Using MikroTik RouterOS 7.14.2
Juniper junos 22.4R3

[sjoko]

Replying with a solution to my own followup;

I was able to solve this by setting fec-mode=fec91 on the Mikrotik, mode auto did not work.
Juniper seemed to use fixed fec-mode set to fec91, I read this in some Junos docs (can't remember where).
I had problems disabling it in the Juniper for interfaces on satellite devices (Fusion).