Configure Intel X550 for 2.5 GbE speed

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Joined: 2014/07/17 04:48:28

Configure Intel X550 for 2.5 GbE speed

Post by larryg » 2021/01/15 22:09:12

I've installed an Intel X550-T1 NIC and am trying to get it to connect to a QNAP Switch at 2.5 GbE speed. After updating the Intel network driver I cannot seem to get it to connect at 2.5 GbE speed, it always connects at 1.0 GbE speed. Prior to installing this card, I had a QNAP QXG-2G1T-I225 2.5GbE NIC, based on the Intel i225-LM chipset, installed and it connect to my switch without problem at 2.5GbE.

Here's the steps I followed
I downloaded the latest Intel Linux driver and built and installed the rpm it creates. The new version (5.9.4) is installed and replaced the original CentOS 8 version (5.1.0-k-rh8.2.0). When using the modinfo command I see

[root@BackupServer /etc/sysconfig/network-scripts]# modinfo ixgbe
filename: /lib/modules/4.18.0-240.1.1.el8_3.x86_64/updates/drivers/net/ethernet/intel/ixgbe/ixgbe.ko
version: 5.9.4
license: GPL
description: Intel(R) 10GbE PCI Express Linux Network Driver
author: Intel Corporation, <>
rhelversion: 8.3

The following information is from the readme file for this driver

Devices that support AQRate (X550 and later) will include 2.5 Gbps and 5 Gbps
in the speeds that the driver advertises during auto-negotiation, even though
ethtool will not display 2.5 Gbps or 5 Gbps as "Supported link modes" or
"Advertised link modes." These speeds are only available through unmodified
auto-negotiation. You cannot use ethtool -s advertise to force auto-negotiation
to advertise 2.5 Gbps or 5 Gbps. If a 2.5 Gbps or 5 Gbps link is created,
ethtool will report the correct link speed.

This implies to me that it should be connecting at 2.5 GbE but it will not. Has anyone installed an Intel X550 and got it to work at 2.5 GbE and has any ideas what could be the problem?

By the way, here's what ethtool is reporting

[root@BackupServer /etc/sysconfig/network-scripts]# ethtool enp1s0
Settings for enp1s0:
Supported ports: [ TP ]
Supported link modes: 100baseT/Full
Supported pause frame use: Symmetric
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 100baseT/Full
Advertised pause frame use: Symmetric
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Speed: 1000Mb/s
Duplex: Full
Port: Twisted Pair
Transceiver: internal
Auto-negotiation: on
MDI-X: Unknown
Supports Wake-on: d
Wake-on: d
Current message level: 0x00000007 (7)
drv probe link
Link detected: yes

Posts: 37
Joined: 2018/04/25 13:30:50

Re: Configure Intel X550 for 2.5 GbE speed

Post by tomkep » 2021/02/28 17:52:26

X550-T is known to experience some issues getting 2.5 & 5 Gbps link speeds depending on the link partner and cable quality. And the omission of full support to "force" these link speeds is not helping here as well.

Fortunately recent ixgbe driver updates from Intel on sourceforge should already include support to selectively enable & disable these two link speeds in 'ethtool -s advertise' command. You can give it a try.

If you are lucky - this may already be available in RHEL/CentOS kernel. If not - it hopefully will show up there soon.

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