Understanding Ethernet media types

About media types

You can configure the speed and the duplex setting, or specify autonegotiation, for an Ethernet interface. The media types available for the filer interfaces are described in the following table.

Note
For 10Base-T and 100Base-T interfaces, the mediatype option of the interface and its link partner (the interface on the other end of the connection) must be the same; that is, both interfaces must be configured either for speed and duplex or for autonegotiation. Otherwise, a duplex mismatch will occur, which can lead to poor performance.

Media-type value	Description
tp	10Base-T, half-duplex
tp-fd	10Base-T, full-duplex
100tx	100Base-T, half-duplex
100tx-fd	100Base-T, full-duplex
auto	Autonegotiate speed, duplex, and flow control. See How media type auto works.
1000fx	1000Base-SX, full-duplex (Gigabit Ethernet Controller)
auto-1000fx	Autonegotiate speed, duplex, and flow control (Gigabit Ethernet Controller)

For information about setting media-type values, see Configuring network interfaces.

Understanding media-type settings for a fiber Gigabit Ethernet interface

The media-type setting for a fiber Gigabit Ethernet interface depends on the type of Gigabit Ethernet controller installed on your filer. You can use the sysconfig command to identify the type of controller on your filer.

If the sysconfig command output indicates that you have a Gigabit Ethernet Controller with a roman numeral as part of its name, you do not specify the media type; the Gigabit Ethernet interface only supports full-duplex. In addition, by default, the interface detects whether the link partner autonegotiates. Based on the outcome of autonegotiation, the operational flow control setting is determined. For example, sysconfig command output for this type of controller might show the following:

slot 4: Gigabit Ethernet Controller III

        e4 MAC Address:     00:03:47:dd:9f:5e (auto-1000sx-fd-up)

If the sysconfig command output indicates that you have a Gigabit Ethernet Controller without the roman numeral as part of its name, you must ensure that the filer interface and its link partner have the same media type configured (that is, both have autonegotiation enabled or disabled); otherwise, the Gigabit Ethernet Controller does not work. The media type auto-1000fx enables autonegotiation and 1000fx disables autonegotiation on the Gigabit Ethernet Controller.

Because the Gigabit Ethernet Controller only supports full-duplex, full-duplex status does not need to be explicitly configured on the interface.

How media type auto works

The behavior of media type auto is determined by the type of network adapter installed on your filer. The following table lists the parameters that are autonegotiated and the possible values for those parameters for each type of network adapter.

Note
You can use the ifstat command determine the speed, duplex, and flow control settings that get negotiated between the interface of the filer and the link partner. For more information, see Displaying network interface information.

Network adapter	Parameters that are autonegotiated (with possible values)
10Base-T/100Base-T	Speed and duplex (half or full)
100Base-T/1000Base-T	Speed. If speed is 100 Mbps, duplex (half or full) and flow control are negotiated. If speed is 1000 Mbps, flow control is negotiated.
10Base-T/100Base-T/ 1000Base-T	Speed. If speed is 10 Mbps, duplex (half or full) is negotiated. If speed is 100 Mbps, duplex and flow control are negotiated. If speed is 1000 Mbps, flow control is negotiated.
Gigabit Ethernet	Flow control.