Important: Auto-negotiation in X4 series adapters is not yet
mature, and should not be used.
To configure the behavior of auto-negotiation on X4 series adapters, use ethtool:
- Configure auto-negotiation on or off:
ethtool -s <interface> autoneg [on|off] - Set auto-negotiation advertised speeds to 1 Gb/s only:
ethtool -s <interface> advertise 0x20 - Set auto-negotiation advertised speeds to 10 Gb/s only:
ethtool -s <interface> advertise 0x1000 - Set auto-negotiation advertised speeds to 1 Gb/s and 10 Gb/s:
ethtool -s <interface> advertise 0x1020 - Identify interface auto-negotiation pause frame setting:
ethtool -a <interface> - Configure auto-negotiation of pause frames:
ethtool -A <interface> autoneg on [rx on|off] [tx on|off]
Note:
If 50G‑CR2 is advertised, auto-negotiation does not request or show ability for
IEEE 10 Gb/s FEC, and does not request or show ability for consortium Clause 91 FEC and Clause 74
FEC. As an effect of this:
- Any advertised 10 Gb/s and 40 Gb/s technologies have no BaseR support if 50G‑CR2 is also being advertised.
- Any advertised 25G‑CR technology has no BaseR or RS FEC support for consortium if 50G‑CR2 is also being advertised.
Note: Due to a limitation in ethtool, when
auto-negotiation is enabled you must also do one of the following to ensure that speed configuration
functions:
- Specify the speed and the duplex mode.
- Specify the speed and set an advertise mask.