Right. Missed that. Thanks. Yes, then I agree. Don't put that switch directly on your wan link.
2 Likes
(I'm glad this subject came up, though. I run my WAN link through a managed switch because it makes it easy to run multiple routers (yes, this is possible with my uplink) or switch between them without physically moving cables. So I double-checked my settings.
On my Dell PowerConnect the management VLAN is fixed at 1. Ordinary paranoia made me set the WAN port's native, untagged VLAN to 86 (to "86" something is an American expression meaning to reject or eject it), and tagged on 201 as required by the carrier. So that's okay.)
1 Like
A dual ethernet (onboard) and USB 3 Raspberry Pi 4b will give you ~ 700 Mb/s.
However, I have a Gigabit FiOS link, and I know it can do better than 700 Mb/s.
I went with a Compute Module 4 with DFRobot board & case, which has the second Ethernet port connect not with USB3, but with PCI express. THAT gives me 900 Mb/s, which is on par using Eero routers. https://www.dfrobot.com/product-2242.html
YMMV. State, local, and VAT taxes are the buyer's responsibility. Void where prohibited.
1 Like
The RPi4 will do 1gbit, if set up correctly.
3 Likes
The DFRobot board is certainly a nice option (and would be even nicer if CM4s were readily available...) but your statement about the Pi 4 + USB dongle is not accurate. It is no trouble at all to get full gigabit speeds with the Pi 4 setup as long as you avoid certain adapters which are known to have less efficient drivers. The TP-Link UE300 is a popular choice because it is cheap, widely available, and performs very well.
3 Likes
The fast availability of a Compute Module 4 is a definite problem. The original estimate I had from Mouser was 5 months (November to March), but Seeed Studio got me one in November. I was prepared to suffer with "only" 700 MB/s performance under OpenWRT until then. 
1 Like
No. I used a Pi 4b with the Vantec Dual USB 3 ethernet adapter (dual RTL8153 PHYs on a single USB port) as my main router for around 6 months (roughly March-Sep 2021), three local routed networks and gigabit fibre WAN. It effortlessly passed 940mpbs in every direction without noticeable CPU, except when doing NAT and PPPoE over WAN; and in that latter case the overhead was no different from an x86 router running PCIe Intel NICs.
USB3 ethernet does not cost 200mbps of bandwidth; or any perceptible bandwidth at all in my experience. Some claim it introduces 1-2ms latency, I never noticed.
Edit: For completeness, one non-default thing i did was manually distribute the interrupt core affinities in /etc/rc.local. In support of that I also added pci=nomsi to the kernel command line*: otherwise you can't move the IRQ affinities for either the built-in Broadcom NIC or the USB3 bus, I forget which. I mainly did this because I didn't like the way the interrupts all piled up on core 0. From memory I think the only real-world problem it solved was when testing multiple simultaneous gigabit streams across 2 or more networks with iperf[3], I bumped against some ceiling or other.
*Note: I don't recommend ever doing this on a general purpose linux system like a desktop, but on a dedicated device running an embedded system like OpenWRT its effects are easily assessed.
4 Likes
Your sweeping generalization is wrong, my USB 3 adapter cost me 200 MB/s
for a month.
As the previously poster noted, it depends on the adapter and its driver.
If the chipset and driver caused the problem, then USB didn't cause it. That same chipset would have cost you 200mbps if it was soldered to the motherboard.
(Aside: the driver does indeed matter. An RTL8153 USB3 adapter that does 941mpbs with ease under Linux only gets me somewhat over 600mbps on a MacBook Air running OSX. Nobody knocks themselves out maintaining 3rd party ethernet drivers for OSX since using them is a niche thing.)
Woah did not understand that whole edit section. I hope that isn't important for maximising the Pi's performance?
Probably not, unless you're running more than one local subnet and have lots of high-bandwidth streams or transfers going through the router simultaneously. And even then, if irqbalance is running (install it if it's not) that'll be close enough.
1 Like
This topic was automatically closed 10 days after the last reply. New replies are no longer allowed.