Use the XCO CLI to add, delete, and show the static IP addresses for management sub interfaces.
efa mgmt subinterface staticip add [ --subinterface sub | --ip1 ip1 | --ip2 ip2]
Here ip1 and ip2 can be either IPv4 or IPv6 address. All other assumptions and limitations for IPv6 static IPs are same as IPv4 static IPs. You can also configure a mix of IPv4 and IPv6 address for ip1 and ip2.
efa mgmt subinterface staticip remove --subinterface <int-id>
efa mgmt subinterface staticip show