Supported vs. advertised link modes for interface

[Patrick_3000]

I have SCALE installed on a server with dual on-board 10 gbps interfaces that use the Intel x550-T2 chipset, and I have one of these interfaces connected to a cable modem that supports maximum 2.5 gbps speed and then passed as a virtual adapter to an OPNsense VM.

The problem is that the interface will not connect at 2.5 gpbs and instead negotiates down to 1 gbps even though the x550-T2 chipset is supposed to support multigig speeds including 2.5 gbps.

I ssh'd into the SCALE server and ran ethtool on the interface, and it listed 2.5 gbps as a supported but not an advertised link mode. I've included the output below.

Does anyone know how to force a supported link mode of speed 2.5 gbps to show as advertised so that I can connect at that speed? I'd rather do this in the SCALE UI because I don't like making command line modifications that could break or cause problems when updating SCALE.

In case it's relevant, the motherboard is ASRock Rack x570d4u-2L2T, and the CPU is Ryzen 7 pro 5750g.

Here is the ethtool output:

Supported ports: [ TP ]
Supported link modes: 100baseT/Full
1000baseT/Full
10000baseT/Full
2500baseT/Full
5000baseT/Full
Supported pause frame use: Symmetric
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 100baseT/Full
1000baseT/Full
10000baseT/Full
Advertised pause frame use: Symmetric
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Speed: 1000Mb/s
Duplex: Full
Auto-negotiation: on
Port: Twisted Pair
PHYAD: 0
Transceiver: internal
MDI-X: Unknown
Supports Wake-on: umbg
Wake-on: g
Current message level: 0x00000007 (7)
drv probe link
Link detected: yes

 

[Patrick_3000]

I solved this by changing an ethtool setting. It turns out that the following command will change the advertised speed for an interface to 2.5 gbps: "ethtool -s [interface name] speed 2500 duplex full" provided that 2.5 gbps is a supported speed. After that, it correctly negotiated with the cable modem to 2.5 gbps.

You can enter this from the command line via ssh, but if you want it to persist after reboot, you'll need to add it as an init script in the SCALE UI under System Settings, Advanced.