USB Ethernet Adapter TP Link TL-UE300 connects only at 10MBit to 100MBit ethernet

[meise21]

Hi,
I am using an USB ethernet adapter on an old i-Mac running Xubuntu 18.04.2LTS. It manages to connect to my 100MBit ethernet but only at slow speed 10MBit.

If I do an ethtool on my adapter I get the following:


Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Half 1000baseT/Full
Supported pause frame use: No
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 10baseT/Half 10baseT/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: Symmetric
Link partner advertised auto-negotiation: Yes
Link partner advertised FEC modes: Not reported
Speed: 10Mb/s
Duplex: Full
Port: MII
PHYAD: 32
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: pumbg
Wake-on: g
Current message level: 0x00007fff (32767)
drv probe link timer ifdown ifup rx_err tx_err tx_queued intr tx_done rx_status pktdata hw wol
Link detected: yes


For some reason the advertised link modes are set to 10baseT/Half and 10baseT/Full only. I tried to manually set the advertised modes to also include 100MBit (half and full duplex) but if I do that the connection stops working. Any idea what is going wrong or how I could get more info?
Thanks in advance!
Markus

[pcfan1234]

Check your switch/modem/router. Important are the speeds supported by the device the computer is connected to.

[meise21]

The switch is a gigabit switch the router to the internet is 100MBit only. I thought this is the reason why "Link partner advertised link modes" shows 100MBit in ethtool.
Connections between other computers on the network are 100Mbit so this shouldn't be the problem.

[pcfan1234]

The advertised link modes are only between 2 directly connected devices. If your computer has a Gigabit NIC and the switch too (and the cable is ok and 8 wires), they can connect with Gigabit, regardless which speed is used between switch and router.
Check your cable. Is it able to connect with Gigabit on another computer/switch?

[meise21]

I played around some more and noticed a strange thing. If I connect both my PC not via my switch to my internet router but directly to my router I get a 100 MBit connection. Interestingly this changes also the values for "Advertised link modes" there I get 10, 100 and 1000MBit when I connect my PC to the router, but only 10MBit when i connect it to my switch (which is at least advertised as gigabit ethernet switch). I'll try more the next days.

[meise21]

Thanks for your tips. The problem was my apparently defective switch. I got a new one yesterday and everything works like a treat now...
Thanks,
Markus