Hi,

I have TL-SG108E for my local network at home. In the Switch settings, I set the ports 1 and 2 to 1000MF connected to my PCs and it works fine in Gigabit mode. I have an IOT device which supports only 100M mode. If I set the port to 100MF, it is auto negotiating to 100M Half Duplex mode instead of 100M Full Duplex mode.

This is in 100MF setting:

$ ethtool eth0
Settings for eth0:
    Supported ports: [ TP     MII ]
    Supported link modes:   10baseT/Half 10baseT/Full
                            100baseT/Half 100baseT/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
    Advertised pause frame use: Symmetric Receive-only
    Advertised auto-negotiation: Yes
    Advertised FEC modes: Not reported
    Link partner advertised link modes:  100baseT/Half
    Link partner advertised pause frame use: No
    Link partner advertised auto-negotiation: No
    Link partner advertised FEC modes: Not reported
    Speed: 100Mb/s
    Duplex: Half
    Auto-negotiation: on
    Port: Twisted Pair
    PHYAD: 8
    Transceiver: internal
    MDI-X: Unknown
netlink error: Operation not permitted
        Current message level: 0x0000003f (63)
                               drv probe link timer ifdown ifup

======

As you can see, it is in Half Duplex mode. My internet speed is also getting capped to 30 Mbps instead of 100Mbps

Link partner advertised link modes is 100baseT/Half

Now, When I set the Speed/Duplex to "Auto" in the switch settings, it is auto negotiating to 100M Full Duplex mode.

See the ethtool output now:

$ ethtool eth0
Settings for eth0:
    Supported ports: [ TP     MII ]
    Supported link modes:   10baseT/Half 10baseT/Full
                            100baseT/Half 100baseT/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
    Advertised pause frame use: Symmetric Receive-only
    Advertised auto-negotiation: Yes
    Advertised FEC modes: Not reported
    Link partner advertised link modes:  10baseT/Half 10baseT/Full
                                         100baseT/Half 100baseT/Full
    Link partner advertised pause frame use: No
    Link partner advertised auto-negotiation: Yes
    Link partner advertised FEC modes: Not reported
    Speed: 100Mb/s
    Duplex: Full
    Auto-negotiation: on
    Port: Twisted Pair
    PHYAD: 8
    Transceiver: internal
    MDI-X: Unknown
netlink error: Operation not permitted
        Current message level: 0x0000003f (63)
                               drv probe link timer ifdown ifup
    Link detected: yes

I tried using different ethernet cable and no change. So, should I use "Auto" mode for this? I am trying to set the ports to 100MF but the OS detects as 100MH. Please advise.