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man pages section 4: Device and Network Interfaces

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Updated: Wednesday, July 27, 2022

mcxe (4D)


mcxe - Mellanox ConnectX-2 10GbE NIC Driver




The mcxe 10 Gigabit Ethernet driver is a multi-threaded, loadable, clonable, GLD-based, STREAMS driver supporting the Data Link Provider Interface, dlpi(4P), on Mellanox ConnectX-2 10GigE controllers.

The mcxe driver functions include controller initialization, frame transmit and receive, promiscuous and multicast support.

Application Programming Interface

The cloning character-special device, /dev/mcxe, is used to access all Mellanox ConnectX–2 10-Gigabit devices installed within the system. It will also support Mellanox ConnectX-2 VPI cards supported by Oracle that have both ports or the second port configured for 10-GBe.

The mcxe driver is managed by the dladm(8) command line utility. dladm allows VLANs to be defined on top of mcxe instances and for mcxe instances to be aggregated. See dladm(8) for details.

You must send an explicit DL_ATTACH_REQ message to associate the opened stream with a particular device (PPA). The PPA ID is interpreted as an unsigned integer data type and indicates the corresponding device instance (unit) number. The driver returns an error (DL_ERROR_ACK) if the PPA field value does not correspond to a valid device instance number for the system. The device is initialized on first attach and de-initialized (stopped) at last detach.

The values returned by the driver in the DL_INFO_ACK primitive in response to your DL_INFO_REQ are:

  • Maximum SDU is 9000.

  • Minimum SDU is 0.

  • DLSAP address length is 8.

  • MAC type is DL_ETHER.

  • SAP (Service Access Point) length value is -2, meaning the physical address component is followed immediately by a 2-byte SAP component within the DLSAP address.

  • Broadcast address value is the Ethernet/IEEE broadcast address (FF:FF:FF:FF:FF:FF).

  • Once in the DL_ATTACHED state, you must send a DL_BIND_REQ to associate a particular SAP with the stream.


The mcxe driver performs auto-negotiation to select the link speed and mode. Link speed and mode can only be 10000 Mbps full-duplex. See the IEEE 802.3 Standard for more information.



Special character device


64-bit device driver (x86)


64-bit device driver (sparc)


Configuration file


See attributes(7) for a description of the following attributes:

PCIe-based systems
Interface Stability

See Also

streamio(4I), dlpi(4P), driver.conf(5), attributes(7), dladm(8), netstat(8)

IEEE 802.3 Standard

Writing Device Drivers in Oracle Solaris 11.4

Network Interface Guide

STREAMS Programming Guide