FIXING my USB3 2.5Gbe network adapters on Linux / Proxmox!

Do you have a USB3 2.5Gbe network adapter (using the Realtek 8156 chipset) that doesn't work well in Linux? Well, the kernel has included the upgraded Realtek drivers for awhile now, but for some reason it needs additional udev rules to load correctly. It's a pretty simple fix and results in dramatically improved bandwidth (full duplex ~1.5Gbps and half duplex ~1.9Gbps), and functions properly with the correct driver.

Link to my blog post which includes the contents of the udev rules you need:

Here's the exact adapter I'm using for my cluster - I chose it because of the price and form factor, there are other options if you prefer USB-C or longer cables.

My Discord Server, where you can chat with me or suggest topics if you'd like:

Timestamps:
00:00 - Introduction
00:41 - The Problem
02:56 - The Solution
04:40 - Testing with iperf
05:58 - Testing Jumbo Frames
08:15 - Conclusion

Some links to products may be affiliate links, which may earn a commission for me.
#networking #realtek #linux

[tzonkov]

Great video. For those coming here after Dec 27, 2023 it seems the latest version of PVE (8.1.3) seems to have this fixed, on mine it loaded the r8152 driver without the workaround.

[harveyharrison]

Like all your segments, super well-paced, excellent delivery of obviously very well understood material..

[blowfly]

Dont forget to add '-M do' to any MTU ping test. -S 9000 will work on most adapters as it will just fragment the icmp request. The '-M do' will prevent the fragmentation and result in an error or no response it the src/dst/link truely does not support the icmp packet size. 1472 is max for 1500 mtu due to ipv4 ethernet overheads. 1452 for ipv6.

[fuzzlabrador]

This video was really helpful! I was having trouble fixing my USB3 2.5Gbe network adapters on Linux / Proxmox, and your instructions were easy to follow. I was able to get everything working in no time. Thanks for sharing your knowledge!

[wbedard]

Yeah, I ran into this same issue when I built out my Proxmox cluster this past year. Google sent me to a great article where someone pointed out this solution. I would note that the HP Elitedesk 805's (1-liter office desktops...) that I'm using have USB 3.1 (10Gbps SuperSpeed) ports. With that configuration, those Sabrent adapters have no trouble hitting 2.4Gbps, event without jumbo frames. Thanks for all the great content you've been creating recently!

[popeter]

your video was absolute perfect timing for me!, was trying to get these to work in a LACP and was having major issues so abandoned that plan, gonna try again now

[jeffgwpg]

Thanks for this! I am a Fedora user and this resolved my issue after the 6.35 kernel was released. Adding the udev rule allowed the USB nic to be detected and once readdressed, I was able to get it working again.

[Schraubfreak]

Great stuff, thanks. It works perfect. I have now around 2.35 Gbits/sec in both directions. But one little thing is that you don't need to restart the Server for the changes. Only "udevadm control --reload-rules && udevadm trigger" and unplug/plug in the adapters do the same.

[ThBeowulf]

This explains a lot... I ended up switching to a Pluggable USB 3 adapter and that worked but I'll have to pull the Sabarent adapters out of the drawer and try them again.

Thanks!

[danieldewindt]

what is the command used at 1:00. is shows all network config in a nice list

[zyghom]

I applied this solution to the card "Anker USB C to 2.5 Gbps Ethernet Adapter" and 2.5Gbps full duplex - thank you ;-)

[ochbad]

wow... I've been building that exact driver from source to solve the same problem. had no idea it was already in the kernel! thanks for the video!

[piero]

Great video and good catch! I was humbling on the same issue, thank you.

[bugon]

funny - I returned my three 2G5 USB NICs last month telling my source "those don't have the RTL chips I ordered" - my bad XD
Please continue to provide the solutions to my problems - it's nice to know I'm not alone 😘

[milesduheaume]

I'm a bit of a Newbe and I've been having a run of straight failures in Projects in my Homelab lately and it's starting to play on my morale! I had just purchased the same adapter for a second NIC to properly implement pfSence, and thought I better just check around about adding a USB NIC to Proxmox; and luckily ran into this. So Man, Thank You! - for solving my problem BEFORE I knew I had one!

[kirksteinklauber]

Love this video as planning to update my small mini PC cluster with Dual NIC on an HA network setup!

[codewithme]

This is my second video of you since I came accross your channel. Amazing. I am going to look through your other videos as well. I have two dual port Mellanox connectx-3 cards with 40/56Gbe firmware. One of them on Dell R720 and another is on my PC. Both run proxmox in cluster and also host Truenas VMs. How should I set my cluster network to take advantage of the speed for storage and VM migration? Adapters are connected via QSFP+ DAC cable.

[hsmptg]

Great video!
I see that you are also a Network expert.
I wonder if you could give a WireShark tutorial on how to see if IPcams are making connections outside our LAN, and how to avoid that by setting properly the firewall on our router.

[daronsong]

😂 how the ipv6 addresses have BEEF and CAFE as part of the network names!!! 😂😂😂😂😂😂😂😂

[wolf]

You might want to check which exact version of RTL8156 these adapters have - which you can by checking the bcdVersion (30.0 is 8156, 31.0 is 8156B, 31.04 is 8156BG, 31.05 as spotted in ASUS version might also be BG or BSG). The original version has some hardware related instability issues including random disconnections and hangs that had to be fixed in hardware...