Issue With Fiber Connection Between Two Locations

[pbiggs]

Hello,

We have two buildings in our campus which are quite close roughly 50 yards or so and we have an old Cisco 3560 connection back to an old switch in our building. They are using large SFPs and SC connectors. This set up is currently working but we want to eliminate the old switches and move over to our Cisco 9400. We have purchased the cables and SFPs to accomplish this. We have SC style patch panels on both ends so we had to get SC-LC connectors to get this working. 

I wanted to start slowly to troubleshoot any issues so I configured the Cisco 9400 (see below) and the Shop 3560 interfaces as a trunk with all the same settings. When we cabled it up it is not working.

We have also tried to add a new Cisco 9200L with the same configuration in the shop with SC to LC connectors and this is not working either. Possible Layer 1 problem? Am I missing anything?

This is the show run output from both sides

3560E-Shop#
interface TenGigabitEthernet0/2
description NEW FIBER TO TR
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,75,200-202,208
switchport mode trunk

9400_1#
interface TenGigabitEthernet5/0/2
description New Fiber from TR to SHOP
switchport trunk allowed vlan 1,75,200-202,208
switchport mode trunk
switchport nonegotiateCisco 3560 Shop Side of Trunk

Thank you in advance for your help with this.

Pete

[M02@rt37]

Hello @pbiggs 

On C9400 Te 5/0/2 does the SFP is recognized ? 

Wich SFP+ have you inserted ?

[pbiggs]

Yes all SFPs are recognized and are working. I’ve tried on both sides. On the new switches I’ve tried both 1 and 10 gig SFPs. That older one is a gbic 10 gig model 

[Reza Sharifi · Accepted solution]

Appears to be a layer-1 issue. If the physical interfaces don't come up, try and swap the strands on one side of the connection and test again.

HTH

[pbiggs]

Thank you I will try this and let you know.

[pbiggs]

I had the chance to try this yesterday but it didn’t work. I’m wondering if speed is the issue here. Having a 1 gig interface on one side and a 10gig interface on the other. 

[pbiggs]

Thank you again! It is working now. 

[Leo Laohoo]

Loop the connections at the optics end and see if the ports light up.

[pbiggs]

I will try this and let you know. Thank you. 

[pbiggs]

I will try this today. Sorry for delay we have also been working on a big wireless project. Thank you!

[pbiggs]

Hello

I wanted to update everyone about the final solution for this issue. After troubleshooting the problem and using a different switches the issue was resolved by flipping the cable and using 1Gig SFP on both sides. It doesn't actually fix the issue with the older switch but we have to replace that anyway and this seems to be a great time to handle that also. The 1gig SFP is in our Cisco 9400 switch in a 10gig port but since we need a 1 gig SFP on the far side using a 1gig SFP worked. Thank you for all your help with this. 

[Reza Sharifi]

Glad to know all is working for you now.