We are in the process of bring up new MLXe routers with 2 port CFP2 100 gig cards. We are connecting these to 870 100 gig QSFP28 interfaces using sr4 optics. We were told to order the CFP2-TO-QSFP28-MOD for the Brocades to convert to QSFP28. We can get link from Brocade to Brocade using the Brocade adapter MPO cables and Brocade sr4 optics. We can get 870 to 870 to link... We cannot get Brocade to 870 to link trying many different things. We can see light from Brocade to 870 via the 870 cli.. We can not see the 870 light in the Brocade. Yet when we got Brocade to Brocade it works... What have we missed?? Has anyone else out there done this before?