I am running TW on my Dell XPS 13 which I hook up to my 23 Inch Dell LCD while I am in my home office through the Dell Thunderbolt DA300 I recently bought. I had originally bought the DA200 with the purchase of the laptop but it did not support the full resolution that my Dell LCD is capable of so I upgraded to the DA300.

Every port on the hub works just fine every-time under the very latest update of TW except for the Ethernet pass through port for some reason. Every once in a while it might be recognized by the Connections window in TW and work for a while but about 98% of the other times it just won't work, as in not recognized, and the port's lights won't turn on despite being connected to a switch.

I have independently checked all the other equipment including the switch, cable being used and the hub itself (under windows and on another machine) and they all work just fine so it has got to be TW related.

I did so preliminary Googling and digging on my own before posting here and it seems that the wired Ethernet uses the Realtek RTL8152 chip, based on that discovery;

Code:
> sudo lshw -C network                            
  *-network                  
       description: Wireless interface
       product: QCA6174 802.11ac Wireless Network Adapter
       vendor: Qualcomm Atheros
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: wlp2s0
       version: 32
       serial: 9c:b6:d0:90:3e:1b
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=ath10k_pci driverversion=5.1.4-1-default firmware=RM.4.4.1.c2-00057-QCARMSWP-1 ip=192.168.1.159 latency=0 link=yes multicast=yes wireless=IEEE 802
.11
       resources: irq:145 memory:dc000000-dc1fffff
  *-network
       description: Ethernet interface
       physical id: 2
       bus info: usb@4:1.2
       logical name: enp57s0u1u2
       serial: e4:b9:7a:9f:3b:d3
       size: 10Mbit/s
       capacity: 1Gbit/s
       capabilities: ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8152 driverversion=v1.09.9 duplex=half link=no multicast=yes port=MII speed=10Mbit/s

So TW can sees it but the card wont register on the Connections window

Code:
> lsmod | grep r8152
r8152                  73728  0
mii                    16384  2 usbnet,r8152
usbcore               303104  8 xhci_hcd,usbnet,usbhid,uvcvideo,btusb,xhci_pci,cdc_ether,r8152

it even shows up on the ip a output;


Code:
> ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: wlp2s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 9c:b6:d0:90:3e:1b brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.159/24 brd 192.168.1.255 scope global dynamic noprefixroute wlp2s0
       valid_lft 603252sec preferred_lft 603252sec
    inet6 fe80::f372:c56f:858d:de8c/64 scope link noprefixroute  
       valid_lft forever preferred_lft forever
4: vmnet1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/ether 00:50:56:c0:00:01 brd ff:ff:ff:ff:ff:ff
    inet 172.16.130.1/24 brd 172.16.130.255 scope global vmnet1
       valid_lft forever preferred_lft forever
5: vmnet8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/ether 00:50:56:c0:00:08 brd ff:ff:ff:ff:ff:ff
    inet 172.16.109.1/24 brd 172.16.109.255 scope global vmnet8
       valid_lft forever preferred_lft forever
7: enp57s0u1u2: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
    link/ether e4:b9:7a:9f:3b:d3 brd ff:ff:ff:ff:ff:ff
8: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 100
    link/none  
    inet 10.8.0.7/24 brd 10.8.0.255 scope global noprefixroute tun0
       valid_lft forever preferred_lft forever

> dmesg | grep enp57s0u1u2
[   10.266758] r8152 4-1.2:1.0 enp57s0u1u2: renamed from eth0
[  367.219056] r8152 4-1.2:1.0 enp57s0u1u2: renamed from eth0

I even tried changing the state of the link from down to up running the
Code:
sudo ip link set dev enp57s0u1u2 up
but it doesn't budge.

I am stuck and have no idea how to follow this up further!

any help would be much appreciated.