YAT on adding a 2.5Gbps port using a USB to Ethernet Adapter (RTL8157)

[jksmurf]

Hi,

I appreciate there’s been lots of prior threads on this attempt as shown in the selective list below, all of which I have now pretty much read. I also appreciate it’s going to be far less of a hassle and a headache to just buy a Wi-Fi 6 class router that has two 2.5Gbps Ports, one WAN and one LAN, but let’s just say the tinkerer in me wants to … tinker, if the cost is low and I can use the gizmo for something else if it’s a no go (which I can).

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Whilst there are records showing the evolution from RTL8156 to RTL8156B to RTL8156BG chipsets (ignoring the Aquantia AQC111U chipsets for now), there has not been much feedback on whether the RTL8157 works (plug and play, with the few required changes in the GUI of course, but no driver compilation, which is beyond my level of expertise).

This Reddit thread suggests better stability and fewer disconnects with the newer RTL8157 chipset based USB to Ethernet adapters (although some Amazon feedback suggest the opposite) so having both a RT-AX86U and a RT-AX86U Pro I thought I’d see if there’s been any update or improvements on the trials for “the quest” of adding a stable 2.5Gbps port?

 

[Tech9]

RTL8157 chipset

If you don't find information about it on SNB Forums - get one, test and report findings.

 

[markwk]

I'm having success with the UGREEN USB 3.1 to 2.5Gbps adapter. This one is very cheap (< $25) on Amazon, and based on the RTL8156BG series of chipsets. In particular ethtool -i reports it as rtl8156b-2 v3 10/20/23. It runs very cool compared to previous gigabit adapters I've used in the past.

With a gigabit fiber ISP feed to my RT-AX86U Pro I'm seeing consistently higher up/down speeds (around 5%, +/- 1%) than the built-in 1Gpbs and 2.5Gbps ports in the Asus router,, according to speedtest.net and other browser-based measurement tools. The metrics from these are coarse IMHO compared to iperf, just FWIW. As to why its faster, that's still a mystery to me?! This adapter can sustain 2.34Gpbs as measured by iperf between an Intel NUC and a desktop with a PCIE 2.5Gpbs card based on the rtl8125b-2_0.0.2 (Alma linux for both). Not quite as fast as two hosts with internal PCIE 2.5Gbps cards, but good enough for the cheap price.

Have had it a couple of months, finger's crossed. Plan is to add dual-WAN with two fiber providers.

 

[Tech9]

The question is what speed it can achieve when connected to the router's USB port. Can you test 2.5GbE port to this USB-to-2.5GbE?

 

[markwk]

The question is what speed it can achieve when connected to the router's USB port. Can you test 2.5GbE port to this USB-to-2.5GbE?

Sorry for the obtuse description, this is connected to the USB 3.0 port on my AX-86U and the fiber WAN feed is connected to it. Flawless for one month now.

 

[Tech9]

But your WAN is Gigabit, no? We have reports for working well adapters, but they can't reach 2.5GbE speeds when connected to the router.

 

[markwk]

Yep, just basic 1Gbps functionality with the current ISP (AT&T), the second ISP (Google) will be energizing our recently-installed yard-box soon (we hope).

Unfortunately 2.5Gbps is kind of falling by the wayside for ISP speeds. Google is only provisioning 1, 3, and 8 in our area for new customers.