CCR2004 25Gb no link

RouterOS General
1

We have a CCR2004-1G-12S+2XS router with a Cisco SFP28-25GSR-85 SFP28 connected through a breakout cable to a Cisco Nexus9000 C93108TC-EX with a Cisco QSFP28-SR4-100G. We are unable to get a link on either the Mikrotik or Nexus. This setup works well with a 40G breakout cable on the Nexus to a 10G SFP+. We are not able to get the 25G working correctly.

Mikrotik - 6.47.4
Auto Negotiation on
Tried also hard coding to 25G
Tx Power 0.824 dBm
Rx Power 0.100 dBm

Cisco Nexus - NXOS: version 7.0(3)I7(8)
interface breakout module 1 port 54 map 25g-4x
Auto negotiation on
Tried speed 25000 and no negotiate auto
Tx Power 0.16 dBm
Rx Power 1.42 dBm

2

We had to set the below on each port on the cisco connecting at 25G:

fec cl108

3

https://www.lookingpoint.com/blog/why-the-fec-wont-my-100gb-and-25gb-links-come-up

4

Thanks, I’ll try that