Khoa Pham's Tech Blog

I’m setting up a new Nexus 5000 vpc cluster. For the keep alive links, I used the old 1GB SFP modules because the links don’t send much traffic. However, it didn’t work

Now that’s interesting because from the Cisco Datasheet, it says

Supported Tranceiver Options:
Cisco SFP-10G-SR 10GBASE-SR SFP+ module (MMF)
Cisco SFP-10G-LR 10GBASE-LR SFP+ module (SMF)
Cisco SFP-H10GB-CU1M 10GBASE-CU SFP+ cable 1m (Twinax cable)
Cisco SFP-H10GB-CU3M 10GBASE-CU SFP+ cable 3m (Twinax cable)
Cisco SFP-H10GB-CU5M 10GBASE-CU SFP+ cable 5m (Twinax cable)
Cisco GLC-T 1000BASE-T SFP
Cisco GLC-SX-MM GE SFP, LC connector SX transceiver (MMF)
Cisco GLC-LH-SM GE SFP, LC connector LX/LH transceiver (SMF)
Cisco SFP-GE-T 1000BASE-T SFP, extended temperature range
Cisco SFP-GE-S GE SFP, LC connector SX transceiver (MMF), extended temperature range and digital optical monitoring (DOM)
Cisco-SFP-GE-L GE SFP, LC connector LX/LH transceiver (SMF), extended temperature range and DOM
Cisco DS-SFP-FC4G-SW 4-Gbps Fibre Channel SW SFP, LC (for Fibre Channel expansion module ports)
Cisco DS-SFP-FC4G-LW 4-Gbps Fibre Channel LW SFP, LC (for Fibre Channel expansion module ports)
Cisco DS-SFP-FC8G-SW 8-Gbps Fibre Channel SW SFP+, LC (for Fibre Channel expansion module ports)
Cisco DS-SFP-FC8G-LW 8-Gbps Fibre Channel LW SFP+, LC (for Fibre Channel expansion module ports)

So I spent a little bit of time playing with the config. It turned out that you have to tell the switch to run at 1Gb on the SFP

I’m on the newest version of Nexus, ver 7.0 N1(1). Not sure why it doesn’t auto-detect the speed. The NX-OS is still evolving, stay tuned for more tips and tricks.