Juniper switch to Cisco Nexus 5k

[cwight2024]

I have Juniper ex-2300 connecting to Cisco Nexus 5k by fiber. The problem is Juniper will show the link lights but cannot bring up the Cisco Switch showing the link down. They have matching SFPs. I have verified that I can bring up the Cisco switch with a lookback jumper.  Has anyone seen this issue? 

[MHM Cisco World]

Check these 

Config  the speed manually, NSK don't support auto nego

Do show stp see if port is BA or not

MHM

[cwight2024]

I will have to check that. I can get the same result with a test Cisco 2960-C.