Does the 2.5G port on RT-AX86U support autonegotiation?

[liug]

On my RT-AX86U Pro, "ethtool eth5" gives

Settings for eth5:
Supported ports: [ TP ]
Supported link modes: 100baseT/Full
1000baseT/Full
2500baseT/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 2500baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: No
Advertised FEC modes: Not reported
Speed: 2500Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 17
Transceiver: internal
Auto-negotiation: off
MDI-X: Unknown
Link detected: yes

I am puzzled by the line "Advertised auto-negotiation: No". Does that mean the 2.5G on RT-AX86U doesn't support auto-negotiation?

If I check a LAN port, eg: "ethtool eth2", I get:

Settings for eth2:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Half 1000baseT/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Half 1000baseT/Full
Advertised pause frame use: Symmetric
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Link partner advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Half 1000baseT/Full
Link partner advertised pause frame use: No
Link partner advertised auto-negotiation: Yes
Link partner advertised FEC modes: Not reported
Speed: 1000Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 3
Transceiver: internal
Auto-negotiation: on
MDI-X: Unknown
Link detected: yes

Now you can see "Advertised auto-negotiation: Yes". Does this mean only the 4 LAN ports support auto-negotiation?

​

 

[RMerlin]

ethtool is a generic Ethernet tool that may not fully support Broadcom's switch. If you query the port with Broadcom's own tool you get a different result.

# ethctl eth5 media-type
    Auto-Negotiation: Enabled
    PHY Capabilities: 2.5GFD|1GFD|100MFD
    Link is Up at Speed: 1G, Duplex: FD

 

[sfx2000]

ethtool is a generic Ethernet tool that may not fully support Broadcom's switch. If you query the port with Broadcom's own tool you get a different result.

One has to be careful with ethtool - as @RMerlin mentions, there's a dependency on the drivers...