Symptom

When a Nexus 3500 is uses a SFP-10G-SR/ SFP-10G-SR , for a standard point-to-point connection, the link will come up fine. However this issue arises when attempting to use the break-in feature. In some cases it will accept the issue command of speed 40000 , and never come up and fail to recognize the Transceiver optic. In other cases it will state "ERROR: Speed is 40G, but the transceiver doesn't support this speed". e.g. switch# sh version | i ima NXOS image file is: bootflash:nxos.7.0.3.I7.2.bin switch# show interface eth1/1 - 8 transceiver Ethernet1/1 transceiver is not present Ethernet1/5 transceiver is present type is 10Gbase-LR switch# show interface eth1/1 - 8 status -------------------------------------------------------------------------------- Port Name Status Vlan Duplex Speed Type -------------------------------------------------------------------------------- Eth1/1 -- xcvrAbsen routed full 40G -- Eth1/5 -- connected routed full 40G 10Gbase-LR

Conditions

if device is running 7.0(3)I7(2) up to 7.0(3)I7(7), while wanting to use SFP-10G-SR Transceiver for a 40G interface, it won't come up.

Workaround

upgrade switch 7.0(3)I7(8) or 9.x or use 10G-LR optic

Further Problem Description