The OBA was configured for 100Full and I configured the Nexus like this:
interface Ethernet1/38
switchport access vlan 238
speed 100
duplex full
logging event port link-status
The OBAs are hot-swappable, if I pulled it out, waited a couple seconds and then reseated it, the link would come up briefly and then go down. The following messages were displayed:
2018 Apr 10 12:25:41 TEST-93108TC %ETHPORT-5-SPEED: Interface Ethernet1/38, operational speed changed to 100 Mbps
2018 Apr 10 12:25:41 TEST-93108TC %ETHPORT-5-IF_DUPLEX: Interface Ethernet1/38, operational duplex mode changed to Full
2018 Apr 10 12:25:41 TEST-93108TC %ETHPORT-5-IF_UP: Interface Ethernet1/38 is up in mode access
2018 Apr 10 12:26:03 TEST-93108TC %ETHPORT-5-IF_DOWN_LINK_FAILURE: Interface Ethernet1/38 is down (Link failure)
You can see that the link would come up, set to 100Full and then go down within 30 seconds.
The solution
It turns out that setting the port using "speed 100" or "speed 1000" and duplex full doesn't disable negotiation. You need to enter:no negotiation auto
in the configuration of the port.
interface Ethernet1/38
switchport access vlan 238
speed 100
duplex full
no negotiation auto
logging event port link-status
The other option was to get credentials for the OBA and set it to auto. Once I did that and removed the no negotiation auto the port came up at 1000 full and stayed up.
interface Ethernet1/38
switchport access vlan 238
logging event port link-status
2018 Apr 10 12:27:16 TEST-93108TC %ETHPORT-5-SPEED: Interface Ethernet1/38, operational speed changed to 1 Gbps
2018 Apr 10 12:27:16 TEST-93108TC %ETHPORT-5-IF_DUPLEX: Interface Ethernet1/38, operational duplex mode changed to Full
2018 Apr 10 12:27:16 TEST-93108TC %ETHPORT-5-IF_UP: Interface Ethernet1/38 is up in mode access